Evidence for involvement of activated CD8+/HLA-DR+ cells in the pathogenesis of neutropenia in patients with B-cell chronic lymphocytic leukaemia

Cytomegalovirus infection does not impact on survival or time to first treatment in patients with chronic lymphocytic leukemia

Human cytomegalovirus (HCMV) is a widely prevalent herpes virus which establishes a state of chronic infection. The establishment of CMV‐specific immunity controls viral reactivation and leads to the accumulation of very large numbers of virus‐specific T cells which come to dominate the immune repertoire. There is concern that this may reduce the immune response to heterologous infections and HCMV infection has been associated with reduced survival in elderly people. Patients with chronic lymphocytic leukemia (B‐CLL) suffer from a state of immune suppression but have a paradoxical increase in the magnitude of the CMV‐specific T cell and humoral immune response. As such, there is now considerable interest in how CMV infection impacts on the clinical outcome of patients with B‐CLL. Utilizing a large prospective cohort of patients with B‐CLL (n = 347) we evaluated the relationship between HCMV seropositivity and patient outcome. HCMV seropositive patients had significantly worse overall survival than HCMV negative patients in univariate analysis (HR = 2.28, 95% CI: 1.34–3.88; P = 0.002). However, CMV seropositive patients were 4 years older than seronegative donors and this survival difference was lost in multivariate modeling adjusted for age and other validated prognostic markers (P = 0.34). No significant difference was found in multivariate modeling between HCMV positive and negative patients in relation to the time to first treatment (HR = 1.12, 95% CI: 0.68–1.84; P = 0.65). These findings in a second independent cohort of 236 B‐CLL patients were validated. In conclusion no evidence that HCMV impacts on the clinical outcome of patients with B‐CLL was found. Am. J. Hematol. 91:776–781, 2016. © 2016 Wiley Periodicals, Inc.

Secondary autoimmune cytopenias in chronic lymphocytic leukemia

Secondary autoimmune cytopenias in chronic lymphocytic leukemia are distinct clinical entities that require specific management. These autoimmune disorders have a complex pathogenesis that involves both the leukemic cells and the immune environment in which they exist. The mechanism is not the same in all cases, and to varying degrees involves the chronic lymphocytic leukemia (CLL) cells in antibody production, antigen presentation, and stimulation of T cells and bystander polyclonal B cells. Diagnosis of autoimmune cytopenias can be challenging as it is difficult to differentiate between autoimmunity and bone marrow failure due to disease progression. There is a need to distinguish these causes, as prognosis and treatment are not the same. Evidence regarding treatment of secondary autoimmune cytopenias is limited, but many effective options exist and treatment can be selected with severity of disease and patient factors in mind. With new agents to treat CLL coming into widespread clinical use, it will be important to understand how these will change the natural history and treatment of autoimmune cytopenias.

The number of cytomegalovirus-specific CD4+ T cells is markedly expanded in patients with B-cell chronic lymphocytic leukemia and determines the total CD4+ T-cell repertoire

B-cell chronic lymphocytic leukemia is associated with immune suppression and an altered T-cell repertoire with expansion of memory cells. Cytomegalovirus (CMV) is a common herpes virus that elicits a strong virus-specific T-cell immune response after infection. We studied the CMV-specific CD4(+) T-cell response in 45 patients and 35 control subjects and demonstrated that it was markedly expanded in the patient group, averaging 11% of the CD4(+) pool compared with 4.7% in controls. The magnitude of the CMV-specific CD4(+) immune response increased with disease stage and was particularly high in patients who received chemotherapy. Within this group, the CMV-specific response comprised over 46% of the CD4(+) T-cell repertoire in some patients. Serial analysis revealed that CMV-specific immunity increased during treatment with chemotherapy and remained stable thereafter. CMV-seropositive patients exhibited a markedly altered CD4(+) T-cell repertoire with increased numbers of CD45R0(+) T cells and a reduction in CD27, CD28, and CCR7 expression. Overall survival was reduced by nearly 4 years in CMV-seropositive patients, although this did not reach statistical significance. CLL patients therefore demonstrate an expansion of the CD4(+) CMV-specific immune response, which is likely to contribute to the immunological and clinical features of this disease.

CD57+ T lymphocytes and functional immune deficiency

CD57(+) expression in T lymphocytes has been recognized for decades as a marker of in vitro replicative senescence. In recent years, accumulating evidences have pointed on the utility of this marker to measure functional immune deficiency in patients with autoimmune disease, infectious diseases, and cancers. We review here the relevant literature and implications in clinical settings.