Chronic GVHD (cGVHD) is the major cause of late non-relapse morbidity and mortality after allogeneic SCT, occurring in up to 70% of long-term survivors. Chronic GVHD commonly affects skin, gut, liver and lung but may resemble autoimmune disorders such as polymyositis, myasthenia gravis, autoantibody-mediated hemolysis and scleroderma.1 However, the pathogenesis of cGVHD is incompletely understood and it remains unclear how autoimmune responses develop. Traditionally, cGVHD is thought to be mediated by donor-derived, alloreactive T cells, but there is mounting evidence of an additional implication of B cells. The pathologic role of B cells might be mediated through dysregulated autoimmune antibody synthesis and allogeneic antibody induction.2 The formation of allogeneic antibodies to Y chromosome-associated antigens (H-Y antigens) after sex-mismatch transplantation and reports about effective treatment of cGVHD with a monoclonal CD20 antibody strengthen this hypothesis.2, 3 These H-Y antibodies were thought to be a product of naive engrafted donor B cells proliferating in response to disparate host antigens.2 Moreover, autoantibodies are frequently detected in association with cGVHD.4 Here, we present a patient who developed antibody-mediated agranulocytosis in association with cGVHD.
A 26-year-old man received a BMT from an HLA–matched, AB0-compatible unrelated male donor for CML in chronic phase not responding molecularly to imatinib, after conditioning with treosulfan, fludarabine and antithymocyte globulin. GVHD prophylaxis consisted of CYA and MTX. He developed acute cutaneous GVHD (grade 1) on day 11 post BMT, which resolved without additional immunosuppressive treatment. On day 33, complete donor chimerism was detected in peripheral blood (PB) and BM by short tandem repeat analysis. On day 89, he presented with complete donor chimerism in PB but discrete mixed chimerism (1–3%) in BM. Subsequently, he developed on day 136 after BMT eosinophilia, progressive nausea and emesis associated with weight loss, which were interpreted as clinical signs of cGVHD, although cGVHD could not be verified histologically by biopsy samples of gastric and duodenal epithelium. Treatment with enteral budenosid resulted in resolution of the gastrointestinal problems, but on day 153, the patient developed autoimmune thrombocytopenic purpura due to IgG autoantibodies against platelet glycoproteins IIb/IIIa and Ib/IX, which was interpreted as an additional manifestation of cGVHD. Therefore, budenosid was replaced by prednisolone at 1 mg/kg/day, which led to rapid resolution of the thrombocytopenia. At this time, PB and BM showed complete donor chimerism and bcr-abl transcripts were not detectable. Although prednisolone was continued, CYA was tapered 9 months after BMT resulting in progressive sicca symptoms of the eyes (NIH grade 1) and a mild cutaneous rash (NIH grade 1) that resolved after restarting CYA. During subsequent tapering of steroids to a every other day (QOD) schedule 15 months after BMT, the patient developed severe neutropenia and was admitted to hospital owing to neutropenic fever on day 431 post transplant. The absolute leukocyte count was 1.5 × 109 cells/l; both lymphocyte and granulocyte counts were diminished to 0.62 × 109 and 0.38 × 109 cells/l, respectively. Antibodies against granulocytes were detected by the granulocyte immunofluorescence test. In brief, granulocytes from healthy blood donors are isolated by density gradient centrifugation, fixed in paraformaldehyde and incubated with the serum to be studied. After washing the granulocytes, cell-bound antibodies are detected with FITC-labeled rabbit anti-human IgG. The granulocyte immunofluorescence test may yield positive results due to HLA class I antibodies, as the corresponding antigens are expressed on neutrophils. HLA I antibodies were excluded in this patient. The rather insensitive granulocyte agglutination test gave a negative result. As HLA class I antibodies could be ruled out and no human neutrophil antigen specificity was identified, these antibodies were most likely autoreactive. At that time, a discrete mixed chimerism (1% recipient origin) was detectable in BM. Besides a slight viral EBV load of 2 × 103 EBV DNA PCR genomes, no other causes for agranulocytosis were detectable including negative testing for cytomegalovirus, Parvovirus B19 and human herpes virus 6. In addition, the patient developed mild-to-moderate hemolysis, with a hematocrit of 24% due to antierythrocyte antibodies (allo-antibodies anti-LW(a) and anti-LW(b)) in association with moderate eosinophilia. As agranulocytosis and hemolysis were interpreted as a manifestation of cGVHD, rituximab was administered at a dose of 375 mg/m2 per week from day 436 for four consecutive weeks, and prednisolone at 1 mg/kg/day and CYA were continued but neutropenia and significant eosinophilia persisted. From day 454, G-CSF at a dose of 34 million IU lenogastrim per day was administered s.c. without effect on the neutropenia. Therefore, high-dose methylprednisolone (10 mg/kg) for four consecutive days was started at day 490, resulting in disappearance of the eosinophilia and rapid hematological regeneration with a neutrophil count of 6.37 × 109 cells/l 3 days after the steroid bolus. The patient was doing well with normal PB counts up to day 539 after BMT, in remission of cGVHD, and receiving immunosuppression with CYA and prednisolone at 1 mg/kg/day. Owing to fluctuating neutrophil counts, treatment with rituximab was repeated six times at a dose of 375 mg/m2. Despite ongoing treatment with rituximab, the patient relapsed again with neutropenic fever on day 561. As IgG serum levels were below 4 g/l on day 561, IgG was administered i.v. with an absolute dose of 30 g. Interestingly, neutrophil recovery was noted 3 days after IgG infusion. A subsequent drop in neutrophil count on day 597 again responded to i.v. IgG. The patient is now doing well with normal PB counts on day 631 after BMT, in remission of cGVHD.
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