A low blood lymphocyte count is associated with an expansion of activated cytotoxic lymphocytes in patients with B-cell chronic lymphocytic leukaemia

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.

Immunogenicity of influenza vaccination in patients with non-Hodgkin lymphoma

PURPOSE

The purpose of this study was to assess humoral response to influenza vaccine in patients (pts) with non-Hodgkin lymphoma (NHL) as compared to healthy subjects (ctrl).

PATIENTS AND METHODS

In two epidemic seasons, 2003/2004 and 2004/2005, 163 pts and 92 ctrl were vaccinated. Antibody titers to hemagglutinin (HA) and neuraminidase (NA) were measured in serum samples collected before vaccination, and 1 and 6 months apart. Changes in antibody titers were assessed by comparing geometric mean titers (GMT), mean fold increases (MFI), and seroprotection and seroresponse rates to baseline values.

RESULTS

Pts vaccinated in 2003/2004 had, after 1 month, increase in GMT by a factor of 8.64-26.60 for antihemagglutinin antibodies (HI) and 6.93-12.66 for antineuraminidase antibodies (NI), as compared to factor of 9.12-24.41 for HI and 4.83-10.31 for NI in ctrl. At 1 month after vaccination, seroprotection and seroresponse rates were similar in both groups, ranging from 68.42 to 84.21% and 71.93 to 94.74% in NHL, and 66.67-82.22% and 62.22-86.67% in ctrl, respectively. Pts vaccinated in 2004/2005 had increase in the GMT by a factor of 38.76-41.49 for HI and 26.59-30.31 for NI, as compared to factor of 81.19-104.32 for HI and 52.16-54.52 for NI in ctrl. Seroprotection and seroresponse rates were lower in the former group, ranging from 62.11 to 65.26% and 74.47 to 77.66%, respectively. In both seasons, pts achieved titres of antibodies greater than the protective threshold, irrespective of the previous chemotherapy administration.

CONCLUSIONS

The results indicate that influenza vaccination induces sufficient immune response in pts with NHL, irrespective of previous chemotherapy.

Distinctive pattern of cytokine production and adhesion molecule expression in peripheral blood memory CD4+ T cells from patients with active Crohn's disease

An expansion of both circulating and intestinal lamina propria CD4+ CD45RO+ T cells has been described in patients with Crohn's disease. We studied both the cytokine profile and the expression of adhesion molecules on this T-cell subset. Peripheral blood CD4+ CD45RO+ T cells from patients with Crohn's disease (n=45) were assessed by flow cytometry and RT-PCR methods. The cytokine profile was also measured in intestinal lamina propria from seven patients. They were classified according to the CDAI and the results were compared with those of patients with ulcerative colitis (n=21) and noninflammatory intestinal conditions (n=15), and healthy controls (n=39). The mean percentage of circulating CD4+ CD45RO+ T cells producing intracellular TNF was higher in active than in inactive Crohn's disease patients (p < 0.001), active (p = 0.49) and inactive ulcerative colitis (p = 0.019), and healthy controls (p =0. 017). TNF expression correlated with CDAI (p < 0.001). An increased expression of intracellular IL-2, IL-6, and IL-10 in active Crohn's disease patients was also found. CD62L was downregulated in active Crohn's disease patients while no differences were observed in CD49d and CD11a expression. Lamina propria CD4+ CD45RO+ T cells from active Crohn's disease lesions showed an increased intracellular staining of TNF, IFN-gamma, and IL-10. Both peripheral and intestinal mucosa CD4+ CD45RO+ T cells from active Crohn's disease patients show an increased production of TNF. In addition, the circulating CD4+ CD45RO+ T-cell subset expresses a pattern of adhesion molecules that promotes homing to extranodal lymphoid tissues. This T-cell subset may play a relevant role in the immunopathogenesis of Crohn's disease.

Active Crohn's disease patients show a distinctive expansion of circulating memory CD4+CD45RO+CD28null T cells

In a previous study we found an expansion of circulating memory (CD45RO(+)) CD4(+) T cells in patients with Crohn's disease (CD). The aim of this work was to investigate the phenotypic and functional characteristics of this T-cell subset in CD. We analyzed in peripheral blood CD4(+)CD45RO(+) T cells from CD patients the expression of surface markers associated to immune activation, costimulation, and apoptosis. In sorted CD4(+)CD45RO(+) T cells apoptosis was quantified by fluorescent annexin V binding. Healthy subjects and patients with ulcerative colitis and acute bacterial enterocolitis served as control groups. An increased percentage of memory CD4(+)CD45RO(+) T cells lacking the expression of costimulatory receptor CD28 was detected in patients with active CD when compared to the other groups evaluated. This expanded CD4(+)CD45RO(+)CD28(null) T-cell subset expressed mostly the effector-cell marker CD57(+). Both CD28 downregulation and CD57 expression correlated to CDAI and surrogate markers of disease activity. These phenotypic changes observed on CD4(+)CD45RO(+) T cells from active CD returned to values similar to healthy controls after clinical remission. Moreover, this memory CD28(null) T-cell subset might express more intracytoplasmic TNF and IFN-gamma than their CD28(+) counterpart. Significantly lower frequencies of memory CD4(+)CD45RO(+) T cells expressing CD95 apoptosis receptor were found in patients with active CD. Moreover, sorted CD4(+)CD45RO(+)and CD4(+)CD45RO(+) CD28(null) T cells from patients with active CD exhibited a lower apoptotic rate than that found in healthy controls and inactive CD patients. According to our data, circulating T lymphocytes from active CD patients show distinctive phenotypic and functional changes, characterized by an expansion of memory CD4(+)CD45RO(+)CD28(null) T cells expressing effector-associated cell surface molecules and displaying enhanced resistance to apoptosis.

Spontaneous apoptosis in chronic lymphocytic leukemia and its relationship to clinical and cell kinetic parameters

Chronic lymphocytic leukemia (CLL) presents considerable variability in clinical presentation as well as in its evolution. In contrast to the inhibition of apoptosis in vivo, spontaneous apoptosis after short-term culture occurs. We studied the degree of this apoptosis in vitro, and its interactions with several clinical and laboratory parameters. Apoptosis was measured by the annexin V technique. Proliferation rate was evaluated by the AgNOR (nucleolar organizer regions) technique. There were inverse correlations between the percentage of annexin V-positive cells and peripheral lymphocyte count (r = - 0.49), Rai stage (r = - 0.40), Binet stage (r = - 0.50), TTM (total tumor mass score; r = - 0.51), and percentage of cells with one AgNOR cluster (r = - 0.45). Direct correlations were found with hemoglobin values ( r = 0.34) and platelet counts (r = 0.52). The number of CD8-positive cells showed a correlation with peripheral lymphocyte count (r = 0.49). When this variable was held constant, a correlation was detected between CD8-positive cells and staging (r = -0.47), TTM (r = - 0.42), and platelet count (r = 0.67). CD4-positive lymphocytes presented a correlation only with CD8-positive lymphocytes. In a cluster analysis, it was possible to create three groups of patients with different apoptosis rates using the TTM and AgNOR values. We conclude that, with the progression of the disease, together with the increase of tumor mass and proliferation rate, there is a decrease in the susceptibility to apoptosis.