Generalised severe recessive dystrophic epidermolysis bullosa (RDEB-GS) is a rare, incurable genetic disorder in which an essential skin component, type 7 collagen (C7), is defective or missing. As a result, skin and mucous membranes detach from the body, causing blisters and wounds. Bone marrow transplantation (BMT) can restore C7 in the skin, probably by supplying mesenchymal stem cells (MSCs) which turn into healthy new skin cells. However, BMT is a risky and unpleasant procedure because the drugs needed to stop the patient's immune system rejecting the donated bone marrow can themselves cause illness and sometimes death. Immune cells in the transplanted tissue may even attack the patient, causing graft versus host disease (GvHD). These doctors at the University of Minnesota tried a different BMT protocol in 10 children with RDEB-GS, using less intense immune-suppression pre-transplant. Three days post-transplant they gave an immunosuppressive drug called cyclophosphamide (PTCy). Two months later, when the patient's body had accepted the donor tissue, they were able to give more MSCs from the same donor. The graft failed in three patients, two of whom underwent repeat BMT followed in one by severe complications and death a year later. Successfully transplanted patients tended to show more C7 in their skin biopsies and improved symptoms with reductions in itch, pain and areas of blistered skin. None suffered GvHD in the short term. The authors conclude that PTCy BMT is feasible in people with RDEB-GS, even with “less-than-perfectly-matched” donors, and allows repeat “top-up” MSC grafts from the same donor.

Background Recessive dystrophic epidermolysis bullosa (RDEB) is a severe systemic genodermatosis lacking therapies beyond supportive care for its extensive, life-limiting manifestations. Objectives To report the safety and preliminary responses of 10 patients with RDEB to bone marrow transplant (BMT) with post-transplant cyclophosphamide (PTCy BMT) after reduced-intensity conditioning with infusions of immunomodulatory donor-derived mesenchymal stromal cells (median follow-up 16 months). Methods BMT toxicities, donor blood and skin engraftment, skin biopsies, photographic and dynamic assessments of RDEB disease activity were obtained at intervals from pre-BMT to 1 year post-BMT. Results Related donors varied from haploidentical (n = 6) to human leucocyte antigen (HLA)-matched (n = 3), with one HLA-matched unrelated donor. Transplant complications included graft failure (n = 3; two pursued a second PTCy BMT), veno-occlusive disease (n = 2), posterior reversible encephalopathy (n = 1) and chronic graft-versus-host disease (n = 1; this patient died). In the nine ultimately engrafted patients, median donor chimerism at 180 days after transplant was 100% in peripheral blood and 27% in skin. Skin biopsies showed stable (n = 7) to improved (n = 2) type VII collagen protein expression by immunofluorescence and gain of anchoring fibril components (n = 3) by transmission electron microscopy. Early signs of clinical response include trends toward reduced body surface area of blisters/erosions from a median of 49 center dot 5% to 27 center dot 5% at 100 days after BMT (P = 0 center dot 05), with parental measures indicating stable quality of life. Conclusions PTCy BMT in RDEB provides a means of attaining immunotolerance for future donor-derived cellular grafts (ClinicalTrials.gov identifier NCT02582775). What's already known about this topic? Severe, generalized recessive dystrophic epidermolysis bullosa (RDEB) is marked by great morbidity and early death. No cure currently exists for RDEB. Bone marrow transplant (BMT) is the only described systemic therapy for RDEB. What does this study add? The first description of post-transplant cyclophosphamide (PTCy) BMT for RDEB. PTCy was well tolerated and provided excellent graft-versus-host disease prophylaxis, replacing long courses of calcineurin inhibitors in patients receiving human leucocyte antigen-matched sibling BMT. What is the translational message? The PTCy BMT platform permits identification of a suitable related donor for most patients and for subsequent adoptive transfer of donor nonhaematopoietic cells after establishment of immunological tolerance.

泛发型重度隐性营养不良性大疱性表皮松解症 (RDEB‐GS) 是一种罕见的不可治愈的遗传疾病,此疾病患者皮肤的主要成分 7 型胶原 (C7) 出现缺陷或缺失。 由此导致皮肤和粘膜与身体脱离,引发水疱和伤口。骨髓移植 (BMT) 可恢复皮肤中的 C7,其机理很可能是提供可转变为健康新皮肤细胞的间充质干细胞 (MSC)。但是,BMT 是一种存在风险的不适操作,因为需要用药来阻止患者免疫系统排斥捐献的骨髓,而这些药物本身可能导致疾病,有时甚至致死。移植组织中的免疫细胞甚至可能攻击患者,导致移植物抗宿主疾病 (GvHD)。 这些明尼苏达州立大学的医生们在 10 名 RDEB‐GS 儿童中尝试了一种不同的 BMT 方案,该方案使用较低强度的移植前免疫抑制。移植后 3 天,向他们给用称为环磷酰胺 (PTCy) 的免疫抑制药物。2 个月后,当患者身体已经接受供体组织时,他们可以从相同供体接受更多 MSC。 此移植在 3 名患者中失败,其中 2 名经历了重复的 BMT,1 名发生了严重并发症,并在 1 年后死亡。移植成功患者在皮肤活检中显示了 C7 增多和症状改善以及瘙痒、疼痛和水疱皮肤面积减少的趋势。短期无人发生 GvHD。 作者们得出结论,PTCy BMT 在 RDEB‐GS 患者中是可行的,甚至使用“不很完美匹配”的供体时也是如此,且允许通过相同供体重复“额外”MSC 移植。

Epidermolysis bullosa (EB) causes mucocutaneous blisters predisposing the host to polymicrobial colonization with potentially resistant organisms. Limited data are available on the microbiology and antibiotic susceptibility in EB patients. Understanding the skin flora in EB may direct clinical care. We reviewed wound cultures from patients with EB to identify their isolates and susceptibilities patterns. Patients, aged 0-22 years were recruited through the EB clinic at the University of Minnesota between 2007 and 2017. We compared susceptibility patterns with the current antibiogram from the University of Minnesota Medical Center (2017). Three hundred and forty-two clinical samples from 68 patients were reviewed. The most common subtype of EB was recessive dystrophic EB (60%). Staphylococcus aureus (SA) was most common (26%), third of which were methicillin-resistant (MRSA), and none were resistant to vancomycin or linezolid. Methicillin-sensitive SA (MSSA) was 72% susceptibility to clindamycin, and 95% to trimethoprim/sulfamethoxazole (TMP/SMX), similar to the published antibiogram. In contrast, the susceptibility of MSSA to erythromycin, ciprofloxacin, and levofloxacin was decreased in the EB cohort, compared to our institution's antibiogram. Decrease susceptibility was also noticed in EB patients for MRSA to clindamycin and TMP/SMX. Pseudomonas aeruginosa (PA) was the second most common organism (14%), followed by coagulase-negative staphylococci (CONS) 12%. PA isolates were 81% susceptible to ceftazidime and 82% to meropenem, similar to the published antibiogram. PA susceptibility to ciprofloxacin was decreased compared to general antibiogram. This study shows over-all decreased susceptibilities pattern in bacterial isolates from EB patients compared to the general patient population in our institution and may guide clinical care especially when choosing empiric antibiotic for a suspected invasive bacterial infection in EB patients.

RDEB is an incurable, often fatal, blistering genodermatosis. Mutations in COL7A1 result in a lack of anchoring fibrils (AFs) between the epidermal basement membrane and the dermal matrix. In 2010, we reported that BMCBT from healthy donors after myeloablative conditioning in 6 patients with RDEB increases C7 expression with parallel improvement in wound healing. As of January 2017, 32 RDEB patients age 5 months to 20 years have been treated by allogeneic BMCBT with follow up ranging from 0.3 to 9 years. The impact of BMCBT on C7 expression was assessed at days 100, 180, and 365 after treatment, and yearly thereafter. Mucocutaneous chimerism was >5% in 27 with increase in C7 expression documented in 12 subjects. Rudimentary AFs were detected in 16. In 13 patients we demonstrated immune-ultrastructural localization of C7 at the sites of AF-like structures at the dermal-epidermal junction, providing additional evidence for generation of new AFs. Based on direct observations and parental reports, 19 of 21 alive with chimerism had mucocutaneous improvement. The probability of survival at 2 years for BMCBT with HLA-matched donors was 69% for high-intensity conditioning (N=13); 81% for reduced-intensity conditioning (N=16). For BMCBT with HLA haploidentical donors and reduced-intensity conditioning, the survival is 100% (N=3). This suggests that patients with severe generalized RDEB can have sustained improvement in mucocutaneous integrity following BMCBT.

Cutaneous and hematopoietic cells synergize in wound healing. Skin fibroblasts and keratinocytes engage in epithelialization and scar formation. Bone marrow-derived inflammatory cells, such as neutrophils and macrophages, contribute to wound repair by phagocytosis and production of cytokines enabling skin repair. While non-hematopoietic bone marrow cells (eg, mesenchymal stromal cells, fibroblasts) also contribute to injury repair, it is unclear whether bone marrow or cord blood cells can functionally replace defective keratinocytes. Here we report early results using allogeneic BMCBT to ameliorate symptoms in patients with severe generalized JEB, a prototypical keratinocyte disorder. Skin engraftment was observed in 5 of the 10 patients (23% and 50% in those with α3 chain of L332-, 3% and 9% in β3 chain of L332-, and 12% in α6β4 integrin-deficient JEB) and associated with increased expression of α3 L332 or β3 chains of L332 but not α6β4 integrin, suggesting different disease mechanisms in these respective forms of JEB. For all JEB forms the overall 2-year survival after BMCBT was 40% (95% CI, 12-67%). Amelioration of symptoms was observed only in patients with mutations in the α3 chain of L332 (L332; N=2). No lasting benefit was observed in individuals with mutations in β3 chain of L332 (N=7) or α6β4 integrin (N=1). We anticipate our data to be a starting point for development of alternative therapies for β3 L332- or α6β4 integrin-deficient JEB, while BMCBT remains an option for those with α3 chain of L332-deficient severe generalized JEB.

RDEB is an incurable, often fatal, blistering genodermatosis. Mutations in COL7A1 result in lack of anchoring fibrils (AFs) between the epidermal basement membrane and the dermal matrix. In 2010, we reported the results of HCT in six patients with RDEB, suggesting that increased C7 expression paralleled better wound healing. As of January 2016, 30 patients aged 5 months to 20 years have been treated by allogeneic HCT with follow up ranging from 2 months to 8 years. At 100, 180, and 365 days after HCT, the impact of allogeneic HCT on C7 expression was assessed by immunofluorescence staining, AFs by transmission and immunoelectron microscopy, resistance to blister formation by skin exposure to negative pressure, chimerism by polymerase chain reaction, and wound healing by clinical photography. A durable improvement in mucocutaneous integrity was demonstrated in 17 of 18 patients alive and engrafted. Out of 30 recipients, mucocutaneous chimerism >5% was observed in 24. An increase in C7 expression was documented in 10 subjects, with C7 detectable before and after HCT in an additional 6. High-density, thick, and/or arching AFs were detected in 16. In 13 patients we demonstrated localization of C7 at the sites of AF-like structures at the dermal-epidermal junction, providing evidence for generation of new AFs. For the entire group, the probability of survival at two years was 77% (CI, 54-90%). Patients with severe generalized RDEB can have an objective and sustained improvement in mucocutaneous integrity following HCT.

BACKGROUND Recessive dystrophic epidermolysis bullosa is an incurable, often fatal mucocutaneous blistering disease caused by mutations in COL7A1, the gene encoding type VII collagen (C7). On the basis of preclinical data showing biochemical correction and prolonged survival in col7 −/− mice, we hypothesized that allogeneic marrow contains stem cells capable of ameliorating the manifestations of recessive dystrophic epidermolysis bullosa in humans. METHODS Between October 2007 and August 2009, we treated seven children who had recessive dystrophic epidermolysis bullosa with immunomyeloablative chemotherapy and allogeneic stem-cell transplantation. We assessed C7 expression by means of immunofluorescence staining and used transmission electron microscopy to visualize anchoring fibrils. We measured chimerism by means of competitive polymerase-chain-reaction assay, and documented blister formation and wound healing with the use of digital photography. RESULTS One patient died of cardiomyopathy before transplantation. Of the remaining six patients, one had severe regimen-related cutaneous toxicity, with all having improved wound healing and a reduction in blister formation between 30 and 130 days after transplantation. We observed increased C7 deposition at the dermal-epidermal junction in five of the six recipients, albeit without normalization of anchoring fibrils. Five recipients were alive 130 to 799 days after transplantation; one died at 183 days as a consequence of graft rejection and infection. The six recipients had substantial proportions of donor cells in the skin, and none had detectable anti-C7 antibodies. CONCLUSIONS Increased C7 deposition and a sustained presence of donor cells were found in the skin of children with recessive dystrophic epidermolysis bullosa after allogeneic bone marrow transplantation. Further studies are needed to assess the long-term risks and benefits of such therapy in patients with this disorder. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00478244.)