Isolated anemia in patients with large granular lymphocytic leukemia (LGLL)

Treatment strategy for acquired pure red cell aplasia: a systematic review and meta-analysis

The treatment of autoimmune acquired pure red cell aplasia (aPRCA) is challenging. Guidelines are based on expert recommendations in the absence of controlled trials. We assessed the efficacy of the main treatment strategy through a systematic review and meta-analysis using MEDLINE, EMBASE, and the Cochrane Library up to September 2022. The overall response rate (ORR) was pooled using random-effects models. In total, 24 observational studies (19 retrospective, median follow-up of 48 months) encompassing 753 patients (49% male) were included. Primary aPRCA represented 57% of the cases. The risk of bias was moderate to high using the ROBINS-I tool. Substantial heterogeneity (I2 > 50%) was retrieved. Corticosteroids as monotherapy as first-line treatment (186 patients, 13 studies) provided an ORR of 47% (95% confidence interval [CI], 34-60). Cyclosporine A was the most frequently used immunosuppressant agent (384 patients, 18 studies), providing an ORR of 74% (95% CI, 66-82) with a similar ORR in first- (73%) and second-line (76%) treatment and when cyclosporin was used as monotherapy (83%) or with corticosteroids (77%). A total of 112 patients (10 studies) received cyclophosphamide, with an ORR of 49% (95% CI, 35-64), which was higher when cyclophosphamide was combined with corticosteroids (48%) and used in second-line treatment (58%) than in monotherapy (31%), and in first-line treatment (44%). Sirolimus use was reported only after cyclosporine A failure and provided an ORR of 87% (95% CI, 68-100; 64 patients, 3 studies). Substantial uncertainty remains regarding the best treatment strategy in the absence of high-quality evidence. This study was registered on the PROPERO database as #CRD42022360452.

Not all LGL leukemias are created equal

Large Granular Lymphocyte (LGL) Leukemia is a rare, heterogeneous even more that once thought, chronic lymphoproliferative disorder characterized by the clonal expansion of T- or NK-LGLs that requires appropriate immunophenotypic and molecular characterization. As in many other hematological conditions, genomic features are taking research efforts one step further and are also becoming instrumental in refining discrete subsets of LGL disorders. In particular, STAT3 and STAT5B mutations may be harbored in leukemic cells and their presence has been linked to diagnosis of LGL disorders. On clinical grounds, a correlation has been established in CD8+ T-LGLL patients between STAT3 mutations and clinical features, in particular neutropenia that favors the onset of severe infections. Revisiting biological aspects, clinical features as well as current and predictable emerging treatments of these disorders, we will herein discuss why appropriate dissection of different disease variants is needed to better manage patients with LGL disorders.

[Pure red cell aplasia: Diagnosis, classification and treatment]

Pure red cell aplasia (PRCA) is a rare anemia characterised by profound reticulocytopenia caused by a marked reduction in bone marrow erythroblasts, without abnormalities in other blood lineages. Blackfan-Diamond anemia is an inherited ribosomopathy responsible for a hereditary form of PRCA. Acquired PRCA are separated in primary and secondary forms, including Parvovirus B19 infection, thymoma, lymphoproliferative disorders, autoimmune diseases (lupus) and drug-induced PRCA. The pathophysiology of PRCA is not fully understood and involves both humoral and T lymphocyte autoreactive cells. In Parvovirus B19-related PRCA, treatment is based on polyvalent immunoglobulins. Thymectomy for thymoma is mandatory but results in prolonged remission in a limited number of cases. The therapeutic strategy is based on expert opinion: corticosteroids in monotherapy provide few sustained responses. The choice of an additional immunosuppressant drug is guided by the presence of an underlying disease. In most cases, cyclosporine A is the first choice providing the best response rate but requires a concentration monitoring (150 to 250 ng/mL). The second choice is cyclophosphamide in large granular lymphocyte leukaemia. Sirolimus (mTOR inhibitor) seems to be a promising option especially in refractory cases. Transfusion independence is the main objective. If the patient receives numerous red blood cell transfusions (> 20 packs), iron overload assessment is crucial to initiate an iron chelation. A retrospective and prospective national cohort (EPIC-F) has been set up and is now available to include each case of PRCA to improve the knowledge of this disease and to optimize the therapeutic strategy.