Successful skin alloplasty and allogeneic finger phalanx transplantation from haploidentical donor in ALL patient with severe chronic GvHD

Introduction

Current treatment strategies in relapsing/resistant (R/R) group in ALL include immunotherapy prior to allogeneic HSCT, as well as development and correction of late severe life-threatening complications. In particular, one should be vigilant for the development of endothelial dysfunction and thrombotic microangiopathy (TMA) in patients after HSCT, and, therefore, being more careful when choosing immunosuppressive prophylaxis and therapy of acute graft-versus-host disease (GvHD). The present clinical case of a patient with a resistant course of acute lymphoblastic leukaemia (ALL) shows that the use of monoclonal antibodies as a "bridge" therapy before haplo-HSCT was justified in this clinical situation. Despite severe lesions of skin, fascia and joint lesions, we managed to stop the development of "overlap" GvHD, due to continuous monitoring, immediate correction of infectious episodes, supervision of appropriate specialists, additional line of aGvHD therapy. Later on, we achieved stabilisation of severe GvHD, resolution of most sclerosed and fibrotic skin areas.

A few successful clinical cases of skin grafting from an allogeneic bone marrow donor have been described, in order to close large or deep areas of skin lesions due to severe GvHD. However, no data have been found of finger phalanx allografting from the bone marrow donor. The presented case is instructive, due to collaboration of surgeons within a multidisciplinary team employing some non-standard approaches in reconstructive surgery, which undoubtedly improved the child's quality of life, allowing him for self-service, attending school and living active lifestyle.

Clinical case description

A male patient, 6 years old, was admitted to the Russian Children's Clinical Hospital (Kazan), being diagnosed with acute B-II lymphoblastic leukemia (standard risk), in December 2015.The patient underwent program chemotherapy according to the ALL-BFM 2000 protocol followed by clinical and hematological remission on the 33^rd day. Maintenance therapy was completed in June 2018. In August 2018, upon maintenance therapy, the first early bone marrow relapse was registered, and p53 deletion was detected using fluorescence in situ hybridization (FISH) technique. The relapse was treated according to ALL-REZ-BFM protocol, blocks F1-F2 resulting in the second clinical and hematological remission. Consolidation chemotherapy (block R2) was then performed.

Since October 2018, the patient has been observed at the RM Gorbacheva Research Institute of Pediatric Oncology, Hematology and Transplantation. In remission state, an aberrant CD19-expressing subpopulation (1% of nucleated cells) was revealed by flow cytometry. The patient was administered Blinatumomab, a bispecific T-cell activator, at standard dosage, in order to achieve MRD-negative remission. During the therapy, persistent febrile fever and enlarged axillary, submandibular, and cervical lymph nodes were noted. A second bone marrow relapse was recorded in November 2018. Due to the progressive and chemotherapy-resistant course, the patient underwent therapy with Inotuzumab Ozogamycin, a monoclonal anti-CD22 antibody. Following a single course of inotuzumab, a complete regression of lymphadenopathy was registered, with normocellularity in bone marrow, blast counts of 0.4%, minimal residual disease (MRD) at 0.02% of nucleated cells. Due to the MRD-positive remission status, consolidation therapy was performed by 2 injections of Inotuzumab Ozogamicin. In January 2019, allogeneic HSCT from a haploidentical donor (maternal graft) was performed.

Considering the extremely high risk of developing transplant-associated microangiopathy (TMA) and veno-occlusive liver disease (VOD), the patient was subjected to non-myeloablative reduced-intensity conditioning regimen, i.e., fludarabine and melphalan (FluMel). Bone marrow was used as a source of hematopoietic stem cells (HSC). GvHD prevention was based on post-transplant cyclophosphamide, sirolimus (Cy, Sir). Calcineurin inhibitors were excluded from the GvHD prophylaxis. The transplant engraftment was based on neutrophil counts being registered on day +22. Since that time, the patient showed the first signs of grade 2 acute GvHD with cutaneous involvement. Basic immunosuppressive therapy with mTOR inhibitors (sirolimus) was continued, and therapy with glucocorticosteroids (GCS) was started (1 mg/kg), with subsequent increase to 2 mg/kg. The therapy resulted into positive dynamics, i.e., regression of rash elements upon reduction of GCS dose to 0.5 mg/kg. Bone marrow examination has confirmed a complete clinical and hematological, MRD-negative remission; p53 deletion was not detected by FISH, and complete donor chimerism was determined by means of STR method.

Later on, however, the recurrence of acute GvHD was noted at reduced GCS dosage, thus requiring mofetil mycophenolate (MMF) administration (750 mg/m²). The development of TMA at the D+60 was observed by increasing serum LDH level up to 566 U/l, high schistocyte ratio (to 38‰), and decreased platelet counts (35×10⁹/L). Therefore, sirolimus was discontinued, and GCS was completely canceled on D+89 after HSCT.

On day +110, the fresh maculopapular rash affected more than 50% of skin surface thus requiring the administration of GCS (1 mg/kg), along with JAK1/JAK2 inhibitor (ruxolitinib) added at a starting dose of 0.15 mg/kg. Positive dynamics were noted for the general skin surface. However, hyperemia and thickening of the skin, erosions and crusts were observed on the foot and palmar surfaces. From D+150 after HSCT, extracorporeal photopheresis (ECP) was added to GvHD therapy, more than 15 sessions of instrumental lymphocyte apheresis were performed, and positive clinical changes were noted thus making it possible to cancel GCS on the D+183.

Hence, the patient developed a steroid-dependent grade 3 cGvHD of the skin and mucosa, classified as "overlap" – syndrome type, which was complicated by TMA episodes, and inability to start therapy with calcineurin inhibitors. Since February 2020, the "off-label" therapy was started with Ibrutinib, a selective and covalent inhibitor of Bruton’s tyrosine kinase enzyme. I.e., the combined immunosuppressive therapy included ruxolitinib, ibrutinib and sirolimus. Nevertheless, the chronic skin GvHD still progressed, mainly in the area of the palms and soles. There were wound bleeding areas at epithelial surfaces, which required daily dressings by a pediatric surgeon.

Local therapy was applied in the form of sanation of wound surfaces and healing creams. Within 5 months, an undulatory response to local therapy was registered. Since July 2020, we observed a secondary wave of wound infections with Staphylococcus aureus, Candida spp. seeded from the lesions. Local sanation of wound surfaces were performed using ointments with antibacterial, antifungal and anti-inflammatory action (Fig. 1).

Figure 1. Severe chronic skin GvHD with sores and secondary infections

Upon disease progression, the skin surfaces became thin and lost their elasticity (turgor) like a parchment layer.

The degree of tissue lesions on feet and hands, combined with extended wound surfaces contributed to development of contractures in the flexion position. The therapy included bandaging the hands like a "glove" in finger extension, plaster casts in the hand extension position, application of individual insoles and inserts, and training with a tutor in physical therapy.

Since August 2020, a positive dynamics was observed by cleaning the wounds. However, the persisting biofilms on the surfaces prevented their healing. Local therapy was replaced by using of atraumatic dressings with enzymatic components. Hand and feet areas prone for bleeding were covered with dressings of mesh structure with anhydrous ointment widely used in combustiology, thus promoting regeneration of epidermis. Local appearance showed positive dynamics with reduction of wound size, absence of secondary infections.

At the end of November 2020, the patient suffered with varicella-zoster virus infection which aggravated the skin changes and epithelization of hands and feet. Since December 2020, the formation of hand and feet contractures was observed (Fig. 2).

Figure 2. The course of chronic GvHD with moderately positive dynamics: cleaning and reduction of the wound surface areas, initial phase of sclerodactyly

The skin at the head, trunk and limbs exhibited signs of systemic scleroderma, by skin tightness and shine, Raynaud's syndrome, limited mobility in joints, along with restriction of mouth opening (formation of a "purse-string"-like mouth), impaired growth of eyelashes and eyebrows. In June 2021, we have registered persistent skin changes associated with tissue thinning, loss of hydration, microcirculatory vascular disorders, areas of dyspigmentation and skin desquamation. There were also scarring changes in the areas of secondary wound healing. However, the applied treatment, physical therapy, immobilization didn’t improve the outcome. The patient developed secondary syndactyly of 1-2-3-4-5 fingers at the both hands, flexion deformities of 2-3-4-5 fingers at both hands, flexion-adduction contracture of 1st finger at both hands, flexion deformity of 1-2-3-4-5 fingers of both feet. The patient underwent prolonged rehabilitation therapy with little effect, followed by the patient's disability and inability for supporting himself (Fig. 3).

Figure 3. Formation of contractures at the hands and feet in the patient with chronic GvHD

In addition to the significant changes in hands and feet, the patient had chronic infectious of ORL organs and eyes manifesting as chronic rhinosinusitis, dacryocystitis, keratoconjunctivitis, as well as multiple caries of temporary teeth due to long-term combined immunosuppressive therapy, skin and mucosal changes. In February 2021, endoscopic transnasal dacryocystorhinostomy was made for lacrimal duct formation. Bacteriology of the purulent discharge revealed a multidrug-resistant Stenotrophomonas maltophilia. In October 2021, the patient developed acute bacterial meningoencephalitis associated with Streptococcus pneumoniae isolated from the liquor, most likely of rhinogenic genesis. Sinusotomy was performed immediately, along with massive antibacterial therapy resulting in complete local recovery. Current stabilization was noted for the chronic cGvHD course accompanied by decreased number of infectious episodes.

Due to positive changes of skin, mucosa and joint lesions, we have performed surgical autodermoplasty of the left hand in May 2022. The surgery included counterposition of the 1^st finger (split flap from the left forearm). Wound healing accompanied by antibacterial treatment proceeded without complications. Grasping function of the 1^st finger of left hand was restored (Fig. 4).

Figure 4. Autodermoplasty of the left hand with counterposition of the 1^st finger

In August 2022, autodermoplasty of the right hand was performed with counterposition of the 1^st finger (split flap from the patient's left thigh). As a result, the 1^st finger of the right hand was contraposed, the base of the other fingers was free of scar deformities due to transplanted split flap. The transplanted flaps were partially engrafted. However, the ligation and pressure bandage have been prematurely removed due to secretion of discharge and fever (on the 8^th day). There were areas of partial flap rejection with secondary infection under the removed dressing. The infectious process was treated by systemic and local antibacterial therapy, the wounds healed by secondary intention within 1 month.

The third stage of hand reconstruction was performed in November 2022. It included autodermoplasty of the intermediate and proximal phalanges of the II to V fingers of the left hand (donor flap from the patient's left forearm). Despite antimicrobial prophylaxis, the post-surgical period was complicated by development of SIRS (systemic inflammatory response) followed by sepsis. The clinical picture developed in acute manner, with persistent fever up to 40°C, intense headaches, giddiness, lethargy, photophobia, vomiting, marked muscle weakness. The patient was immediately brought to the intensive care unit (ICU). At this time, the inflammation markers were as follows: C-reactive protein (CRP) increased from 1.21 mg/L to 97 mg/L, procalcitonin (PCT) level increased from initial 91 ng/mL to 247 ng/mL, along with marked metabolic and lactic acidosis. Blood clotting pattern corresponded to the disseminated intravascular coagulation (DIC) syndrome Clinical blood analysis revealed increase of leukocytes up to 56×10⁹/L with high neutrophil counts, thrombocytopenia 24×10⁹/L, schistocytosis up to 90‰. Blood biochemistry showed an increased levels of LDH (2640 U/L), creatine (0.125 mmol/L), urea (14 mmol/L), bilirubin (30 μmol/L), AST (1657 U/L), AST (456 U/L).

Myocardial damage and development of secondary cardiomyopathy was confirmed by serum markers, i.e., increased myoglobin (4105 ng/mL, reference, 17.4-106), creatinine phosphokinase (4357 ng/mL, reference, 0.6-6.3), high-sensitivity troponin I (106 ng/L, reference, 0.0-17.8).

ECHO-CG data: moderate decrease in systolic and diastolic function by restrictive type, Simpson ejection fraction decreased to 41.5%. ECG showed severe heart dysfunction, with heart rate of 99 beats per 1 minute, diffuse reduction of ventricular complexes. The patient had multiorgan failure: renal, hepatic, cardiovascular. The skin showed a severe vascular damage with multiple hemorrhages and peripheral thrombosis, especially in the upper and lower limbs.

This clinical pattern corresponded to the thrombotic microangiopathy associated with hematopoietic stem cell transplantation (TA-TMA) induced by an acute infections process, as well as massive long-term immunosuppressive therapy and prior monoclonal antibody therapy (MAT). Therefore, the entire immunosuppressive therapy has been canceled considering the risks of drug-induced TMA. A search of infection was performed: bacterial meningitis was excluded, active infectious process in ORL organs was excluded by CT scanning of paranasal sinuses. In the lung CT scans, we revealed focal infiltrative changes and bilateral subsegmental atelectasis in S9, S10, along with pleural effusions up to 10 mm. Bronchial lavage was collected at endoscopic videobronchoscopy, and the galactomannan Aspergillus fungal antigen was detected, with increased positivity index of 1.404. Parainfluenza and adenovirus were also found in BAL specimens by means of direct immunofluorescence (PIF).

In the area of postoperative wounds, we registered some delayed changes within 3 days of septic process: II-V fingers of the left hand in the area of transplanted skin flaps, mainly projected to the proximal phalanges. Partial rejection of the graft was observed, with hemorrhages under the skin flaps, the fingers are completely viable, with saved sensitivity at the site of donor flap collection (left forearm). Still the patient with sepsis and TMA exhibited cyanosis and trophic disorders in the scar areas of previously operated 1^st finger of the right hand dated August 2022 (Fig. 5).

Figure 5. Trophic changes of the first finger at the right hand (left) with subsequent outcome in dry necrosis of the nail phalanx (right)

Areas of partial rejection of the transplanted skin flaps in the projection of the proximal phalanges of the II-V fingers of the left hand were healed by secondary intention. Meanwhile, the trophic changes of soft tissues of the 1^st finger of the right hand resulted in dry necrosis of the nail phalanx.

Differential diagnosis was made between hemolytic-uremic syndrome (HUS) associated with infection, thrombotic thrombocytopenic purpura (TTP), and thrombotic microangiopathy associated with HSCT (TA-TMA). Additional laboratory tests showed normal levels of ADAMTS13 activity in plasma (55.2%, with reference values of 40 to 130%), haptoglobin, 0.348 to 0.104 g/L (reference values of 0.3 to 2.1 g/L). Coombs direct test for anti-erythrocytic antibodies to IgG, IgA, IgM, C3c, C3d was negative.

The intensive therapy included correction of acid-base balance, and combined antibacterial treatment (carbapenems, aminoglycosides, linezolid). Antifungal therapy was carried out with liposomal amphotericin B. Eculizumab (a recombinant humanized anti-C5 monoclonal antibody) was administered on the first day at the dose of 600 mg followed by a session of membrane plasma exchange. In total, 3 weekly injections of eculizumab (600 mg) and 2 sessions of membrane plasma exchange were performed. Within first 3 days of treatment, we have registered a decrease in proinflammatory markers, rhabdomyolysis markers, stabilization of blood clotting parameters with gradual resolution of DIC, decrease in common biochemical indices, recovery of renal and hepatic function, cardiac muscle contractility and ventricular ejection fraction. Paresthesia has became milder, along with gradual recovery of muscle tone, and improvement of most trophic changes in affected tissues. The patient’s physical status was stabilized.

The patient was discussed at a multidisciplinary consultation representing the RM Gorbacheva Research Institute of Pediatric Oncolgy, Hematology and Transplantology and N. Pirogov Clinic of High Medical Technologies. To remove the sources of dry necrosis, in absence of available autograft for covering the wound surfaces, we have decided to perform skin grafting with allogeneic tissues of maternal origin (from a haploidentical HSCT donor). At the end of January 2023, the following plastic surgery was performed on the right hand of patient: (1) arthrolysis of the metacarpophalangeal joint of the first finger; (2) formation of a stump of the first finger; (3), skin grafting to the palmar surface and to the 1^st, 3^rd, 4^th and 5^th fingers.

A free skin flap was taken from the HSC donor (patient’s mother), the graft was collected in the area of the left forearm. The surgical wounds healed without complications, both in donor and recipient. Complete engraftment of the transplanted skin flap was accompanied by antibacterial therapy, considering a risk of TMA development (Fig. 6).

Figure 6. Arthrolysis of the metacarpophalangeal joint of the 1^st finger of the right hand; a stump is formed at the 1^st finger (left), skin grafting on the palm surface and on the 1, 3, 4, 5 fingers of the right hand (right)

Due to persistence of scleroderma and fibrotic changes in the skin and joints, we have tried selective inhibitor of ROCK2 isoenzyme with antifibrotic activity approved by the Medical Commission since February 2023. The drug was applied at a dose of 200 mg daily per os. The therapy was well tolerated, being followed by improvement of skin elasticity and significant reduction of skin tightness thus enabling us to form skin folds all over the body, with tightness and skin shine retained on the scalp. Dyspigmentation and hyperpigmentation of skin were less pronounced, along with reduced tissue scarring. The function of mouth opening and motor function of the lower jaw has improved significantly. The child became active, well tolerates physical loads, being actively engaged in physical therapy, he is growing and gaining weight. Duration of the course therapy amounted to 9 month.

However, the function of the right hand and grip was still lost, there was soft tissue thinning, soreness and hypersensitivity at the finger stump. A decision was required whether to amputate the finger or to cover the stump with an additional skin flap. Taking into account the readiness of the parent and child for functional restoration, the patient was consulted again by a multidisciplinary team and Ethical Committee, and the decision was made for reconstructive surgical intervention.

Autografting of a toe was not possible in this case, due to flexor deformities of 1-2-3-4-5 toes at both feet. The option of taking a toe from the foot of a stem cell donor without affecting donor’s foot function was discussed. In October 2023, a following surgical intervention was performed: (1) the donor nail phalanx of the 2^nd toe at the right foot was allografted on a vascular pedicle to the position of nail phalanx at the 1^st finger of the right hand, with skin autodermoplasty (Fig. 7).

Figure 7. Allotransplantation of the nail phalanx of the 2^nd toe of the right foot, to the position of the nail phalanx of the 1^st finger on the right hand with skin autodermoplasty, and left hand subject to autodermoplasty (a). Left and right hands, 9 months after allografting of the nail phalanx (b)

Complete engraftment of the finger phalanx and skin flap was registered, and the postoperative period proceed without complications, accompanied by antibacterial therapy, immunosuppressive therapy, with control of the probability of TMA development. Over 6 months of rehabilitation period, we have detected a restored sensitivity of the transplanted finger, recovery of the grasping function of large and small objects. No trophic disorders were detected during the follow-up period.

Discussion

In pediatric practice, relapse of acute lymphoblastic leukaemia occurs in 10-20% of patients, and event-free survival in patients after the second and third relapses is barely 25% and 15%, respectively [1, 2]. The chemotherapeutic approach in the treatment of such relapses does not always provide a long-lasting effect thus requiring allogeneic HSCT at later terms. An alternative approach to the treatment of R/R ALL suggests targeted therapy with a monoclonal antibody, inotuzumab ozogamicin, an anti-CD22 antibody conjugated to a cytotoxic agent (calicheomycin). Upon binding to CD22-positive cells, calicheomycin is released into the cell, leading to DNA breakage and cell death [5]. Appropriate response rates have been shown in a pediatric phase I study, with overall response rate of 80% (95%, CI: 59-93%), and 84% of patients (95%, CI: 60-97%) achieving negative minimal residual disease status [3]. One-year overall survival was 55.1% (95%, CI: 39.1-77.7%). Seven patients (25%) exhibited serious adverse events manifesting as sinusoidal obstruction syndrome (SOS). Six cases were diagnosed after treatment with inotuzumab early after HSCT, and one case was documented after treatment for relapse after allo-HSCT [4]. The overall incidence of hepatotoxic complications is reflected in three large phase I/II studies B1931010, phase II and phase III studies INO-VATE.

The incidence of SOS was 8% among patients after HSCT and 4% in cases without HSCT (phase I/II B1931010 study). The phase II study showed the SOS incidence of 7% in patients treated weekly with inotuzumab ozogamicin, and in 23% of cases with single drug administration being followed by HSCT. In the phase III INO-VATE study (n=327), the incidence of SOS was 22% in patients receiving HSCT, and 8% among patients without HSCT [6, 7, 8].

Essentially, SOS is the result of damage to endothelium of liver microvessels and hepatocytes, leading to local deposition of red blood cells which obstruct the sinusoidal flow and subsequently cause liver damage and haemorrhagic necrosis [9,10,11]. In addition to the well-known clinical picture, laboratory changes such as decreased platelet levels, antithrombin III, protein C, factor VII and plasminogen activator inhibitor I activities may be seen in SOS [12]. Endothelial damage is a well established pathological substrate in SOS. However, there is increasing evidence for endothelial dysfunction involved in other complications such as acute GvHD and graft-associated thrombotic mycroangiopathy (TA-TMA) [13].

Endothelial cells support an anti-inflammatory and antithrombotic conditions thus maintaining normal blood flow by the fine tuning of vasculature and homeostatic balance. Various innate and adaptive immune responses and pathogen-associated molecular patterns in infections, along with toxic effects of immunosuppressive drugs, chemotherapy or radiotherapy, are considered highly negative with respect to the endothelial functions [14, 15]. TA-TMA results from accumulation of microthrombi, causing microcirculatory disturbances, leading to ischaemic organ dysfunction, especially of renal, intestinal and CNS vessels [16]. Among pathophysiological mechanisms of endothelial damage, activation of the alternative pathway of complement activation seems to be the main scenario in the TA-TMA development, which may be triggered by several factors, e.g., pathogen surface residues, deregulation of non-specific basal activation and antigen-antibody complexes. Either pathway converge on a membrane-antibody complex composed of C5b-9 proteins that binds to the surface of infectious pathogen or cells. Their destruction causes neutrophil activation, resulting in release of neutrophil extracellular traps (NETs) which then activate the complement cascade, inducing a direct damaging effect on the endothelium [18, 19].

The main infections associated with TA-TMA are caused by fungi (aspergillosis) or viruses, e.g., cytomegalovirus, adenovirus, HHV6, parvovirus B19 and BK-virus [17].

According to various studies, the incidence of TA-TMA developing after allo-HSCT ranges from 10 to 35%, with an onset time of 20 to 90 days after stem cell transfusion, although cases of later onset are also known. Several large studies have reported mortality rates of 50-75% in the first 3 months after TA-TMA diagnosis [17]. Among the main clinical and laboratory diagnostic criteria for TA-TMA, one may highlight such complications as multiorgan failure syndrome with renal involvement, pulmonary hypertension, arterial hypertension, posterior reversible encephalopathy syndrome and polyserositis. The most important laboratory markers of TA-TMA risk are as follows: thrombocytopenia, anaemia, shistocytosis, increased serum LDH, elevated C3, sC5b-9, proteinuria, normal ADAMTS13 level, negative Coombs' test (direct, indirect), decreased serum haptoglobin, autoantibodies to factor H [16, 22].

The main therapeutic approaches include withdrawal of calcineurin inhibitors and mTOR antagonists, antimicrobial therapy in case of evident infectious agents, therapeutic plasma exchange (especially in the presence of autoantibodies to factor H), etanercept, rituximab (used in some cases of TA-TMA), defibrotide and eculizumab [20, 22].

Severe GvHD is another risk factor for the development of TA-TMA. Some studies have shown a 4-fold increase in the TMA frequency in patients with GvHD [21]. TMA development in the context of GvHD is promoted by secondary endothelial damage in presence of circulating cytokines, reduction of vascular endothelial growth factor, activation of blood clotting, and endothelial damage caused by cytotoxic T-lymphocytes.

Chronic GvHD is among the most common complications after allogeneic HSCT and may affect up to 70% of recipients [23]. Steroid dependency and steroid resistance in GvHD patients remains a clinical problem in about half of patients with chronic GvHD and requires supplementary therapy for 2 years. There is still a proportion of patients who do not respond to therapy or do not have a sustained response [24]. Along with classic chronic GvHD, one may encounter the "overlap" GvHD (ocGvHD) with combined clinical signs of both acute and chronic GvHD at the same time [25]. The incidence of ocGvHD in pediatric population ranges from 3 to 39%, which is almost two times lower than in the adult patient cohorts [26]. The ABA2 study has evaluated clinical outcomes of cGvHD and ocGvHD in two cohorts of pediatric and adult patients (n=92). The cumulative incidence of cGvHD at 1 year after HSCT was 49.7% and 63.1%, respectively, depending on the cohort. Classic GvHD was observed in 62% of patients (n=57); cGvHD, and ocGvHD was observed in 38% of cases (n=35). Two-year OS in patients with cGvHD was 92%, with ocGvHD significantly lower at 64%. One-year relapse-free mortality was 17% in patients with ocGvHD compared to 0% in patients with cGvHD. This study suggests higher risk of serious complications in ocGvHD, with more severe symptoms and clinical course than in cases with classic cGvHD, and a much higher mortality rate [27].

There are only few articles in the literature describing skin lesions with the progression of deep wounds and ulcers associated with cGvHD [28]. In the absence of appropriate treatment, skin rejection resulting from GvHD may increase the risk of secondary infection due to massive erosive surfaces, ulceration and damage to underlying tissues [29]. Recurrent infection is one of the major mortality factors in patients with cGvHD due to the severe course of infectious episodes during long-term systemic immunosuppressive therapy [28].

Moreover, cGvHD is an immune-mediated disease characterised by chronic inflammation and fibrosis. The progression to fibrosis involves macrophages producing profibrotic cytokines, tumour growth factor beta (TGF-β) and platelet-derived growth factor alpha (PDGF-α), leading to collagen deposition secreted by activated fibroblasts [30].

In this view, Belumosudil, the selective ROCK2 inhibitor, has shown efficacy in recipients older than 12 years with persistent cGvHD who have failed to respond to 2-5 prior lines of systemic therapy. It reduces the production of IL-17 and IL-21, pro-inflammatory cytokines and mediators of autoimmunity. In a phase II clinical trial involving 65 participants with predominantly severe cGvHD, complete resolution was observed in 6% of patients and partial response in 69%, with a duration of response over 50 weeks [31]. Changes in cytoskeletal dynamics under the action of ROCK also lead to increased transcription of profibrotic genes. Activation of these genes promotes fibroblast differentiation into myofibroblasts and increases collagen production, which are key features of fibrotic diseases [32]. ROCK2-mediated effects on cytoskeletal dynamics and intracellular inflammatory cascades represent a promising therapeutic target for the treatment of various immune-mediated and fibrotic diseases [33].

The joint, muscular and skeletal manifestations caused by cGvHD are known to be associated with development of contractures, impaired motor activity of patients, and limitation of their vital activity and physical disability. A team from Spain presented 118 patients, 39 of whom (33%) developed eosinophilic fasciitis, but it is noteworthy that 11 of them had isolated joint contractures without sclerotic skin lesions [34]. The musculoskeletal problems concern large cohort of patients with severe course of cGvHD being managed by long-term physical rehabilitation [35].

The course of cGvHD associated with development of large wound defects requiring surgical intervention, is severely complicated by impaired wound healing ability, and the possibility of performing autologous skin flap transplantation is often not possible due to the lack of healthy skin areas in patients with extensive skin changes [36-38].

An interesting study concerned a long-term experience with cGvHD patients observed from 2009 to 2016 in Regensburg (Germany) and Karolinska University (Sweden). The authors presented seven cases with severe course of skin cGvHD and deep cutaneous ulceration affecting large areas. The patients were subjected to allogeneic skin flap grafting from the haematopoietic stem cell donors. All seven allogeneic skin grafts were tolerated and provided skin function over the damaged area without evidence of immunological damage to the transplanted flaps. In 3 out of 7 patients, skin flap transplantation was performed in 2 stages due to the presence of extensive wound defects and the inability of single-stage covering [36].

Refractory skin ulcers in patients with cGvHD remain a therapeutic challenge and are the result of prolonged inflammation with subsequent tissue fibrosis and peripheral vascular damage, leading to impaired microcirculation. The inflammatory state of skin ulcers carries the risk of attracting alloreactive immune cells that keep the risk of worse wound healing. Skin defects in the course of cGvHD are, therefore, extremely difficult to treat with standard surgery. In the case of complete donor chimerism after HSCT, one may expect tolerance to skin grafts from stem cell donors, thus allowing allogeneic skin transplantation [38].

Conclusion

This case of pediatric ALL with resistant/relapsing clinical course shows that the use of monoclonal antibodies is quite rational as a "bridge" therapy before haplo-HSCT. However, one should take into account the risk of endothelial dysfunction and TMA in patients after HSCT. Therefore, we must be careful when choosing the mode of immunosuppressive prophylaxis and therapy of aGvHD. Despite severe lesions of skin, fascia and joints, we managed to cancel the development of "overlap" acute/chronic GvHD due to continuous monitoring, immediate correction of infectious episodes, supervision of appropriate specialists, applying new lines of AGvHD therapy over time, thus achieving stabilisation of severe GvHD, resolution of most sclerotized and fibrotic skin areas. A multidisciplinary strategy of treatment and rehabilitation involved original approaches to reconstructive surgery playing a leading role in management of the patient, which undoubtedly improved the child's quality of life, allowing him to serve himself, live an active lifestyle and attend school.

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