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We investigated in systemic sclerosis (SSc) patients the T cell homeostasis and its relationship with the clinical course of the disease. Distribution of peripheral T cell subsets, thymic output, lymphocyte proliferation and apoptosis were analyzed by flow cytometry or ELISA. Age inappropriate levels of naive CD4+ T cells and thymic output were observed. Proliferation of CD4+ T cells, lymphocyte apoptosis and CD4+ regulatory T (Treg) cell frequency were significantly higher than those observed in controls and significantly correlated with clinical phenotypes and clinical progression parameters i.e., diffusing capacity of the lung for carbon monoxide (DLCO) and disease activity. These data indicate that the evaluation of the T cell homeostasis can represent a valuable prognostic tool for SSc patients and it is useful to distinguish between limited and diffuse phenotypes. A therapeutic intervention targeted at reversing T cell homeostasis abnormalities would therefore potentially be helpful in counteracting disease progression.

A European multicenter study was conducted to obtain information on the current practices of immunoglobulin administration, the policies in use for the surveillance of the risk of hepatitis C virus (HCV) transmission, and the natural history of HCV infection in patients with hypogammaglobulinemia. Data from 1243 patients with primary immunodeficiencies in 16 countries demonstrated that 90% of patients with antibody deficiencies receive intravenous immunoglobulins in an inpatient setting, and 7% of patients are treated with subcutaneous immunoglobulins, mainly at home. Wide variations have been reported regarding the frequency and the type of tests monitored for the surveillance on the risk of viral hepatitis transmission. Only 60% of patients have been tested at least once for HCV RNA detection. Data from 71 HCV-infected patients demonstrated a rapid progression of HCV infection, with end-stage liver disease, in about 40% of patients. Ten percent of patients spontaneously cleared the virus, and about 30% are asymptomatic. Patients with CVID have a worse prognosis than patients with XLA.

T cell apoptosis represents a common mechanism of T cell depletion in HIV-1-infected individuals reflecting maturational and functional T cell abnormalities either directly or indirectly induced by the virus. In the present study, the effects of highly active antiretroviral therapy (HAART) on the spontaneous apoptosis of distinct T cell subsets were investigated during a 6-month follow-up in a cohort of HIV-1-infected individuals with CD4 + cell counts between 100 and 500 cells/μl and plasma HIV-1 RNA levels ≥10,000 copies/ml. We determined that the rapid and sustained increase of both naive (CD45RA + CD62L + ) and memory (CD45R0 + and CD45RA + /CD62L − ) CD4 + and, to as lesser extent, CD8 + T cells in peripheral blood was associated with a significant decrease of apoptotic CD4 + and CD8 + as well as CD3 + CD4 − CD8 − T cells. Among CD4 + lymphocytes, at enrollment, the highest frequency of apoptotic cells was observed within the memory compartment, as defined by CD45R0 expression. During HAART, however, the frequency of CD4 + CD45R0 + apoptotic T cells progressively decreased in association with a significant downregulation of surface activation markers that indicated decreased levels of systemic immune stimulation. These results indicate that effective viral suppression can contribute to progressive normalization of maturational and functional T cell abnormalities responsible for the high levels of T cell apoptosis in HIV-1-infected individuals. This, in turn, may contribute to a reduced rate of T cell loss and immune reconstitution during HAART.