Parveen Bose

Regulatory T-cells in B-cell chronic lymphocytic leukemia: their role in disease progression and autoimmune cytopenias

Abstract Regulatory T-cells (Tregs) have been shown to be important for the balance of autoimmunity and oncogenesis. Tregs have a protective role in autoimmune diseases and conversely promote oncogenesis. Chronic lymphocytic leukemia (CLL) is unique in being at the cross-roads of oncogenesis and autoimmunity. We studied Tregs, defined as CD4+CD25highCD127lowFOXP3+, in 32 treatment-naive patients with CLL. Our study shows that patients with CLL had a higher absolute Treg count than the control group (p < 0.001). A progressive increase of Tregs was noted in advanced stages of the disease (p < 0.001). The increase in absolute Treg count is more significant than the increase in percentage Tregs. The absolute Treg count appears to be more important in disease pathogenesis. The absolute Treg count was significantly higher in those patients having autoimmune cytopenias. There was an inverse correlation between lymphocyte doubling time and absolute Treg count (p = 0.03). The absolute Treg count may be used as a prognostic marker in CLL.

Regulatory T-cell and T-helper 17 balance in chronic lymphocytic leukemia progression and autoimmune cytopenias

The reasons for progression and autoimmune cytopenias (AIC) in chronic lymphocytic leukemia (CLL) are not entirely clear, with previous studies suggesting a role for regulatory T-cells (Treg). In this study we prospectively studied Treg (CD3 + CD4+ CD25highCD127low), interleukin-10 (IL-10) producing Treg and T-helper 17 (Th17) (CD3 + CD4+ IL-17+) cells in 40 treatment-naive patients with CLL. The percentage of Th17 and not Treg cells was significantly higher in the AIC cohort than in those without AIC (p < 0.0001). The Treg:Th17 ratio was skewed in favor of Th17 in the AIC cohort (p = 0.02). Th17 cells are responsible for AIC of CLL. Analysis of lymph-node aspirates showed that the percentage of Treg and IL-10 expression in Treg and not Th17 was significantly higher than in peripheral blood (p < 0.01). Treg cells play a major role in the microenvironment where disease progression occurs. This shows the importance of maintaining the Treg:Th17 equilibrium, for imbalance leads to CLL progression or AIC.

Frequency of Paroxysmal Nocturnal Hemoglobinuria Clones by Multiparametric Flow Cytometry in Pediatric Aplastic Anemia Patients of Indian Ethnic Origin

The literature on paroxysmal nocturnal hemoglobinuria (PNH) in aplastic anemia (AA) is largely focused on adults with few studies in children. Moreover, large studies are conspicuously absent from developing countries. Knowledge of the prevalence and utility of their detection is required before widespread use of PNH screening in pediatric AA in resource‐limited settings.

Paroxysmal Nocturnal Hemoglobinuria is rare cause for thrombosis of the intra-abdominal veins in the ethnic Indian population - results from FLAER-based flowcytometry screening.

Paroxysmal nocturnal hemoglobinuria (PNH) may present as cytopenia, hemolysis, or thrombosis at unusual sites including splanchnic vessels. Thrombosis of the portal veins and hepatic veins are associated with thrombophilic risk factors: deficiencies of protein C, protein S, and antithrombin, positivity for antiphospholipid antibodies, and factor V Leiden mutation. There is limited information regarding PNH presenting primarily as a thrombotic event. We prospectively screened 142 consecutive patients with intrabdominal thrombosis and 106 controls with fluorescently labeled inactive toxin aerolysin (FLAER)‐based flowcytometry to assess the frequency of PNH as a thrombophilic risk factor in patients with intra‐abdominal thrombosis.

Danazol increases T regulatory cells in patients with aplastic anemia

ABSTRACT Objectives: Danazol is an attenuated androgen and is used in the treatment of aplastic anemia (AA) in resource constraint settings. We chose to study the role of CD4+ CD25high CD127low FoxP3+ T regulatory cells (T-regs) in the pathophysiology of AA and their response to treatment with Danazol alone or in combination with immunosuppressive treatment (IST). Methods: T-regs’ percentages of 25 acquired idiopathic AA patients and 25 healthy controls who completed study protocol were analyzed by performing multicolor flowcytometry on peripheral blood samples. Results: More than one-third (36%) of AA patients in our study received Danazol as monotherapy, whereas less than a third (32%) each received standard doses of IST with equine Anti Thymocyte Globulin (ATG) and Cyclosporine combination, or Cyclosporine and Danazol combination, respectively. Results showed that all AA patients had a significantly lower percentage of T-regs at the time of diagnosis when compared to healthy controls (p < 0.0001), implicating their role in the pathophysiology. On treatment, all 25 patients showed a significant rise in the percentage of T-regs when compared to baseline (p < 0.0001). Discussion: The rise in T-regs’ percentage was higher in patients treated with Danazol alone when compared to standard IST (ATG with Cyclosporine), or Cyclosporine with Danazol combinations (p = 0.585). Conclusion: We conclude that Danazol also leads to increase in T-regs in acquired idiopathic AA.

Haematological profile of patients with mixed-phenotype acute leukaemia from a tertiary care centre of north India

Background & objectives: Mixed-phenotype acute leukaemia (MPAL) is a rare neoplasm with no definite treatment protocols and a distinctly poor outcome. Advancement in polychromatic flow cytometry has made its identification easier. This prospective study was designed to identify cases of MPAL and study their clinical presentation and haematological profile in a tertiary care hospital in north India. Methods: Ethylenediaminetetraacetic acid (EDTA)-anticoagulated bone marrow aspirate samples of patients diagnosed as acute leukaemia (AL) on the basis of morphology were utilized for immunophenotyping. A comprehensive panel of fluorochrome-labelled monoclonal antibodies targeting myeloid, B-cell, T-cell and immaturity markers was utilized. The patients diagnosed to have MPAL, on the basis of the World Health Organization 2008 classification, were selected for further analyses. Results: There were 15 (2.99%) patients with MPAL of the total 501 cases of AL. Seven were children, all males and mean age of 5.08±3.88 yr. Eight were adults, male:female=6:2 and mean age of 21.43±5.74 yr. Eight were diagnosed as B/myeloid and seven were T/myeloid. No association was observed between age and immunophenotype of MPAL. On morphology, 11 were diagnosed as AML and four as ALL, and no specific morphology of blasts was predictive of a MPAL. Interpretation & conclusions: MPAL appeared to be a rare neoplasm (2.99% of AL cases). A comprehensive primary panel of monoclonal antibodies should be used to identify this neoplasm known to have a poor outcome.

Paroxysmal nocturnal hemoglobinuria clones are not infrequent in patients with inherited bone marrow failure syndromes

The distinction of inherited bone marrow failure syndromes (IBMFS) from other acquired forms of aplastic anemia (AA) is very important for instituting proper therapy. However this is not often straight forward. A proper confirmatory genetic diagnosis is possible only in less than 50% of the patients even with the use of massive parallel sequencing (1). Moreover its application is still limited due to the cost and several logistical issues. Unfortunately, diethyl epoxy butane (DEB) or mitomycin C induced chromosome breakage studies (CBS) is the only test, which is widely employed, for the diagnosis of IBMFS in many resource-limited settings. This article is protected by copyright. All rights reserved.