CDR3-independent expansion of Vδ1 T lymphocytes in acquired chronic pure red cell aplasia

Lenalidomide-induced pure red cell aplasia is associated with elevated expression of MHC-I molecules on erythrocytes

The RVd therapy, combining lenalidomide, bortezomib, and dexamethasone, is a mainstay treatment for multiple myeloma. A multiple myeloma patient developed pure red cell aplasia (PRCA) following RVd treatment, despite the absence of common PRCA triggers. In vitro analyses reveal lenalidomide as a pivotal disruptor of erythropoiesis. Single-cell transcriptome analysis unveils hyperactive CD8+ T cells and impaired erythropoiesis in the patient's bone marrow. Unexpectedly, the patient's erythroid cells display abnormally high expression of genes in the antigen presentation pathway, particularly those for major histocompatibility class I (MHC-I) molecules. Functional assays demonstrate that lenalidomide treatment further augmented MHC-I expression in the patient's erythroid cells. Blocking MHC-I or depleting T cells alleviates the defective erythropoiesis of PRCA, suggesting that the interaction between erythroid cells with elevated MHC-I and T cells in the bone marrow might contribute to PRCA. Taken together, our study implicates a mechanism underlying lenalidomide-induced PRCA in treating cancer patients.

Successful treatment of a pure red-cell aplasia patient with γδT cells and clonal TCR gene rearrangement: A case report

Pure red-cell aplasia (PRCA) is a syndrome associated with reduced erythroid precursors. This report presents the case of an elderly PRCA patient with significantly proliferated γδT cells and clonal T-cell receptor (TCR) gene rearrangement. The cause of this patient's PRCA was confirmed to be an autoimmune disorder rather than malignancy on the basis of flow cytometry, TCR gene rearrangement, and positron emission tomography/computed tomography (PET/CT) findings. Moreover, the γδT cell group identified in this case was captured for the first time under the microscope; this CD4+/CD8- (extremely high CD4/CD8 ratio) population is rare in PRCA patients. Our patient with a monoclonal and polyclonal hybrid of TCR gene rearrangement was sensitive to cyclosporin A (CsA), despite previous reports suggesting that patients with TCR clonal rearrangement may respond poorly to this drug. Overall, this case presents valuable clinical findings for the future diagnosis and management of PRCA caused by autoimmune conditions and further research on γδT cells' autoimmune pathophysiology and gene rearrangement.

Induced complete remission faster in adult patients with acquired pure red cell aplasia by combining cyclosporine A with corticosteroids

To evaluate whether the adult patients with acquired pure red cell aplasia (PRCA) could benefit more from cyclosporine A (CsA) combined with corticosteroids (CS) than CsA or CS alone.Seventy-three patients were evaluated in 2 institutions (6 patients lost to follow-up).The induction therapy included CsA (n = 21), CS (n = 21), or CsA combined with CS (n = 31), and remission was achieved in 16/21 (76.2%), 10/21 (47.6%), and 21/31 (71.0%) patients, respectively. Higher complete remission (CR) rate was achieved in CsA combined with CS group than in CS group (61.3% vs 19.0%, P = .003). Patients achieved CR faster in CsA combined with CS group than in CS group or CsA group (median time, 1 month vs 2 month vs 3 month, P = .010). By multivariate analysis, CsA combined with CS therapy and primary PRCA were the influence factors for CR rate. Twenty-seven patients relapsed due to discontinuation or tapering therapy, and 19 patients regained response by increasing the dose of original regimens or changing to other immunosuppressive therapy. Complete remission to induction therapy was a correlative factor for death (P = .035).CsA combined with CS produced faster and higher CR rate in treating adult patients with PRCA than did CsA or CS alone.

Pure red cell aplasia complicating the course of long-standing mantle cell lymphoma

Pure red cell aplasia (PRCA) is a rare cause of severe hypoplastic anemia characterized by profound depletion of erythroid precursors. Although PRCA may be associated with lymphoproliferative diseases, it has never been described in mantle cell lymphoma (MCL). We report what to our knowledge is the first case of a patient with indolent, non-nodal MCL complicated by PRCA. The patient presented with severe hypoproliferative anemia in the setting of a long-standing diagnosis of B-cell chronic lymphocytic leukemia. Bone marrow studies revealed the complete absence of erythroid progenitors. Cyclin D1 positivity on immunohistochemistry, confirmed by a positive FISH for t(11;14) (q13;q32), established the final diagnosis of MCL in conjunction with PRCA. Rituximab monotherapy led to rapid remission of splenomegaly and the leukemic picture, but the patient achieved transfusion independency only with subsequent administration of cyclosporine-A, and remained so during the subsequent 15 months despite the gradual disease recurrence.