B-cell-directed therapy for chronic graft-versus-host disease

Low-dose rituximab in steroid-refractory chronic graft-versus-host disease

BACKGROUND

Chronic graft-versus-host disease (cGvHD) is a major complication that puts patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at risk of death or infection. Currently, there is no gold standard for the first-line treatment of patients who do not respond to steroids, and there are several therapeutic options being evaluated in clinical trials for this disease to be used even in the first-line treatment for GvHD. There is evidence of the benefit of rituximab, an anti-CD20 antibody, at a standard dose of 375 mg/m2 weekly in the treatment of steroid-refractory chronic graft-versus disease (SR-cGvHD).

OBJECTIVE

To demonstrate the safety and efficacy of low-dose rituximab in a middle-income center in northeastern Mexico STUDY DESIGN: We report the experience of 26 patients with chronic graft-versus-graft disease who received low-dose rituximab (100 mg weekly for 4 weeks). We utilized the advances in the National Institutes of Health (NIH) criteria for diagnosis, scoring, trial design, and assessment of treatment response.

RESULTS

We obtained a 5-year overall survival of 23.6%, including four patients with complete response. The 1-year event-free survival was 70% for patients with rituximab. During the treatment, there were 3 hospitalizations, and the causes were: immune thrombocytopenia, a parapneumonic effusion, and a cerebral vascular event. The median length of hospital stay was twelve days.

CONCLUSION

A low dose of rituximab is an available and cost-effective option for patients with steroid-refractory cGvHD.

Membranous Nephropathy with Crescent after Hematopoietic Cell Transplantation

A 44-year-old man who received allogenic hematopoietic stem cell transplantation after being diagnosed with acute myeloid leukemia developed nephrosis when the dose of tacrolimus was tapered. A renal biopsy showed the granular deposition of immunoglobulin G in the glomerular basement membrane and subepithelial electron-dense deposits, crescent formation, C4d-positive staining of the peritubular capillary, and subendothelial swelling, suggesting that the main pathological diagnosis was membranous nephropathy and that chronic graft-versus-host disease played a role in the etiology of nephrosis. We herein report a case of membranous nephropathy with various pathological findings. C4d deposition suggests complement activation and the involvement of humoral factors.

Antibodies targeting surface membrane antigens in patients with chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplant reflects a complex immune response resulting in chronic damage to multiple tissues. Previous studies indicated that donor B cells and the antibodies they produce play an important role in the development of cGVHD. To understand the pathogenic role of antibodies in cGVHD, we focused our studies on posttransplant production of immunoglobulin G antibodies targeting cell surface antigens expressed in multiple cGVHD affected tissues, due to their potential functional impact on living cells in vivo. Using plate-bound cell membrane proteins as targets, we detected a significantly higher level of antibodies reactive with these membrane antigens in patients who developed cGVHD, compared with those who did not and healthy donors. Plasma-reactive antibody levels increased significantly prior to the clinical diagnosis of cGVHD and were reduced following cGVHD therapies including prednisone, interleukin-2, or extracorporeal photophoresis. Using cell-based immunoprecipitation with plasma from cGVHD patients and mass spectrometry, we identified 43 membrane proteins targeted by these antibodies. The presence of antibodies in cGVHD patients' plasma that specifically target 6 of these proteins was validated. Antibodies reactive with these 6 antigens were more frequently detected in patients with cGVHD compared with patients without cGVHD and healthy donors. These results indicate that antibodies that target membrane antigens of living cells frequently develop in cGVHD patients and further support a role for B cells and antibodies in the development of cGVHD.

Chronic graft-versus-host disease presenting as eosinophilic fasciitis: therapeutic challenges and an additional case

Chronic graft-versus-host disease (cGVHD) is one of the main late complications of allogeneic hematopoietic stem cell transplant and a major contributor to the mortality and morbidity in surviving recipients. Skin is the most common involved organ in cGVHD and may mimic a wide spectrum of dermatological conditions in its clinical and histopathologic manifestations. Some of the commonly simulated diseases are scleroderma, morphea, and lichen sclerosus. Chronic GVHD simulating eosinophilic fasciitis (EF) is relatively rare, frequently presenting with skin induration, a typical "peau d'orange" appearance, peripheral blood eosinophilia, myalgia, arthralgia, and arthritis leading to joint contractures in severe cases.Diagnosis is based on clinical manifestations and histopathology. Treatment is challenging because most cases are refractory to first-line therapy of glucocorticoids and calcineurin inhibitors (CNIs), and there is no standard second-line therapy.We report a comprehensive review of literature on all reported cases of CGVHD presenting as EF. We also describe an additional interesting case of cGVHD presenting as EF that was resistant to traditional therapy of high-dose glucocorticoids and cyclosporin A, but showed complete resolution of skin manifestations after addition of imatinib.Chronic GVHD presenting as EF is a rare variant of sclerodermatous cGVHD. Diagnosis is difficult, and treatment of cGVHD mimicking EF remains a therapeutic challenge because of obscure pathogenesis and poor response to traditional immunosuppressive medications. Emerging insights into the pathogenesis of cGVHD have resulted in the development of novel targeted therapies, which may improve outcomes and should be attempted in this subset of the disease. Larger studies are warranted to substantiate these preliminary findings.

Treatment of chronic graft-versus-host disease in 2011

PURPOSE OF REVIEW

This article summarizes recent reports on the risks, pathogenesis and treatment of chronic graft-versus-host disease (GVHD).

RECENT FINDINGS

Chronic GVHD remains an elusive disorder to characterize and to treat. Recent evidence on tolerance induction by regulatory T-cells and on B-cell involvement shed some insights into the pathogenesis of chronic GVHD. In a recent large comparative study, the overall risk profiles for acute and for chronic GVHD were similar, but risk factors were not changed after adjustment for prior acute GVHD, supporting the concept that chronic GVHD is not an end stage of acute GVHD. Glucocorticoids remain the standard initial treatment of chronic GVHD, but the outcomes are not satisfactory, particularly for patients with high-risk features. Many treatments for chronic GVHD including extracorporeal photopheresis, rituximab, sirolimus, mycofenolate mofetil, imatinib, pentostatin and infusion of mesenchymal stem cells have been reported in several retrospective and relatively small phase I/II studies with a wide range of overall responses.

SUMMARY

No current therapies used for chronic GVHD have been approved by the US Food and Drug Administration. Large well designed prospective studies are warranted to establish better treatments. Targeted therapies based on the pathogenesis of chronic GVHD may lead to better outcomes.

The immunological phenotype of rituximab-sensitive chronic graft-versus-host disease: a phase II study

Chronic graft-versus-host disease is the major long-term complication after allogeneic stem cell transplantation with a suboptimal response rate to current treatments. Therefore, clinical efficacy and changes in lymphocyte subsets before and after rituximab treatment were evaluated in a prospective phase II study in patients with steroid-refractory chronic graft-versus-host disease. Overall response rate was 61%. Only responding patients were found to have increased B-cell numbers prior to treatment. B cells had a naïve-antigen-presenting phenotype and were mainly CD5 negative or had a low CD5 expression. Normal B-cell homeostasis was reestablished in responding patients one year after ritxumab treatment and associated with a significant decline in skin-infiltrating CD8(+) T cells, suggesting that host B cells play a role in maintaining pathological CD8(+) T-cell responses. Imbalances in B-cell homeostasis could be used to identify patients a priori with a higher chance of response to rituximab treatment (Eudra-CT 2008-004125-42).