Prophylactic red blood cell exchange for prevention of severe immune hemolysis in minor ABO-mismatched allogeneic peripheral blood progenitor cell transplantation after reduced-intensity conditioning.

BACKGROUND: Delayed severe immune hemolysis due to donor-derived passenger lymphocytes is observed in minor and/or bidirectional ABO-mismatched transplants, especially after reduced-intensity conditioning (RIC). The incidence is reported in up to 30 percent of patients and can result in multiorgan failure (MOF) and death. STUDY DESIGN AND METHODS: A first group of 32 patients (historical control) underwent RIC followed by allogeneic hematopoietic peripheral blood progenitor cell transplantation at our institution. In 5 of 10 patients with a minor and/or bidirectional ABO-mismatched graft, severe immune hemolysis was observed, leading to death in 3 of them. Therefore, we initiated a protocol with prophylactic red blood cell (RBC) exchange in minor and/or bidirectional ABO mismatch of a second group of patients (study group) and investigated the incidence of hemolysis, transplant-related mortality (TRM), and overall survival (OS) and compared these data with the historical control group. Twenty-two of 80 patients in the study group had a minor and/or bidirectional ABO-mismatched donor. RESULTS: In 20 patients, a prophylactic RBC exchange was performed. Three patients showed mild to moderate citrate reactions, and in 1 patient the procedure had to be stopped because of hypotension. Eighteen of 20 patients engrafted uneventfully, 1 patient rejected his graft, and another 1 showed signs of mild hemolysis. In the minor and/or bidirectional ABO-mismatched setting patients in the study group had a lower risk for TRM at 1 year compared to patients in the historical control group (16% vs. 53%, p < 0.05) and a better 1-year OS (65% vs. 40%, p < 0.05). CONCLUSION: RBC exchange is a safe procedure, reducing the incidence of delayed severe immune hemolysis and thus the risk of TRM in minor and/or bidirectional ABO-mismatched cases.

A single-center pilot validation study of a new chronic GVHD skin scoring system.

The use of a quantifiable and reproducible measurement tool for skin manifestations of chronic graft-versus-host disease (cGVHD) is key for the successful assessment and documentation of therapeutic response. Skin scoring methods for use in clinical trials have not been validated for application in patients suffering from cGVHD. For this purpose we performed a prospective single-center pilot study to validate a skin-scoring tool developed at our institution for evaluating cutaneous involvement of cGVHD approximately 10 years ago. It combines percentage of involved body surface area (BSA) divided into 10 separate anatomic regions with manifestations of cGVHD coded from 0 (normal skin) to 4 (hidebound skin, unmovable sclerosis). Sixteen patients were examined separately by 4 trained physicians 3 times on 2 consecutive days for a total of 192 individual skin assessments; intraobserver and interobserver reliability were calculated. Good to excellent intraclass correlation coefficients (ICC) were obtained in almost all scores including erythematous lesions in areas with scores 3 and 4 for all observers. Moderate to good interrater reliability for observers 1 to 4 was seen in lesions with scores 0, 3, and 4, respectively. A marked improvement of interrater reliability in all scores and examinations was observed when ICCs were calculated only for the more experienced observers 1 to 3. This New Chronic GVHD Skin score is a reproducible, accurate, feasible, and inexpensive tool for use in selected clinical trials of chronic cutaneous GVHD. Further studies with larger patient numbers and validation of this new tool for assessment of treatment response are warranted.