leptin and Common-Variable-Immunodeficiency

Adiponectin exerts beneficial pleiotropic effects through three receptors, AdipoR1, AdipoR2, and T-cadherin; it also exerts immunomodulatory effects. We previously demonstrated that adiponectin levels are altered in common variable immunodeficiency disease (CVID). The purpose of the present study was to investigate further the specific involvement of adiponectin in CVID by characterizing (i) the expression profile of adiponectin receptors on peripheral blood mononuclear cells; (ii) the levels of another relevant adipokine, namely leptin; (iii) the levels of five other cytokines (IL-2, IL-6, IL-10, TNFα, and IFNγ) in 24 patients on maintenance therapy, in 18 treatment-naïve patients (before and 24 h after the first Ig infusion) and in 28 healthy controls. We found that (i) adiponectin was down-expressed in patients on maintenance therapy and in treatment-naïve patients, and that it increased in treatment-naïve patients 24 h after the first Ig infusion; (ii) leptin expression did not differ between maintenance patients and controls either before or after the first Ig infusion; (iii) AdipoR1 expression was significantly higher on B lymphocytes, monocytes and NK cells of CVID patients than in controls; (iv) the expression of AdipoR1 and AdipoR2 on B lymphocytes, monocytes and NK cells was higher after the first Ig infusion than in treatment-naïve patients; (v) T-cadherin expression did not differ between treatment- naïve CVID patients and controls, and was not affected by Ig infusion; and (vi) IL-6, IL-8, IL-10, and TNFα levels were differently expressed in CVID patients on therapy maintenance and were not affected by the first Ig replacement therapy. This is the first study to demonstrate that the expression of AdipoRs in peripheral blood mononuclear cells from CVID patients differs from that of controls, and changes after the first Ig infusion. The specificity of adiponectin involvement in CVID is supported by the absence of changes in leptin levels and in the levels of the cytokines investigated. Taken together, these results suggest that the adiponectin system plays an important and specific role in CVID. A better understanding of adiponectin as a link in the cross-talk between the immune system and adipose tissue may provide additional benefits for the management of CVID patients.

Topics: Adiponectin; Adult; Cadherins; Common Variable Immunodeficiency; Cytokines; Female; Humans; Immunoglobulins; Leptin; Leukocytes, Mononuclear; Male; Middle Aged; Receptors, Adiponectin; Tumor Necrosis Factor-alpha; Young Adult

Leptin is involved in the control of energy storage by the body. Low serum leptin levels, as seen in starvation, are associated with impaired inflammatory T cell responses that can be reversed by exogenous leptin. Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and recurrent infections. Several defects in T cell function have also been described, and allergy, autoimmune disease, and lymphomas or other malignancies can be present. Previous studies in Brazilian CVID patients have shown that, in contrast with mononuclear cells from healthy controls, CVID cells cultured with phytohemagglutinin and added leptin increased the proliferative response and decreased activation-induced apoptosis. Interleukin (IL)-2 and especially IL-4 production also increased significantly, although the effects of exposure to leptin were not observed uniformly in CVID patients. The majority, however, responded in some degree, and some exhibited completely restored values of the four parameters.These remarkable results indicate leptin could be used to improve immune function in these patients. On the other hand, we found no specific correlation between serum leptin levels and the number of infectious events over a 24-month period, presence of autoimmunity, allergies, or cancer in these patients. The results suggest that the absolute value of serum leptin does not determine the clinical behavior of patients or responses to leptin in vitro. Of note is the divergence between serum leptin, response to leptin in vitro, and the presence of autoimmunity, indicating the need to identify the cellular and molecular players involved in the regulation of the immune response by leptin in CVID.

Topics: Adult; Animals; Case-Control Studies; Common Variable Immunodeficiency; Humans; Immunity; Leptin

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by hypogammaglobulinemia. Leptin has been implicated as an antiapoptotic compound as well as a stimulant of the immune response. Leptin administration is capable of reversing the immune deficiency that occurs upon starvation. We investigated a possible role for leptin in CVID; a condition associated with lowered plasma leptin levels. Thirty-eight patients were studied. Addition of leptin to the tissue culture media of PBMC from CVID patients increased the proliferative response of lymphocytes to mitogens and decreased activation-induced apoptosis of these cells. IL-2 and specially IL-4 production also increased significantly upon addition of leptin to the PBMC cultures. Our results suggest that leptin may be involved in some of the cellular defects observed in CVID and indicate a novel therapeutic strategy to improve immune function in these patients.

Topics: Adolescent; Adult; Apoptosis; Cohort Studies; Common Variable Immunodeficiency; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Humans; Interleukin-2; Interleukin-4; Leptin; Linear Models; Lymphocyte Activation; Male; Middle Aged; T-Lymphocytes

Common variable immunodeficiency (CVI) is a primary immunodeficiency syndrome characterized by impaired production of antibodies and recurrent infections. Delay in diagnosis leads to metabolic wastage and low body weight. Leptin, a hormone produced by white adipose tissue, modulates insulin action by signal transduction cross-talk and by direct action on pancreatic beta-cells. We hypothesized that patients with CVI might present a defective regulation of leptin production and insulin resistance.. Thirteen CVI patients (39 +/- 11 years) under gammaglobulin replacement were evaluated in parallel with 13 gender-, age-, body weight- and body mass index (BMI)-matched healthy voluntaries, and with data from two large population series, the Bruneck and the Hoorn Studies.. Serum leptin and insulin levels, homeostasis model assessment - insulin resistance (HOMA-IR), body composition, haematological, biochemical and immunoglobulin measurements were obtained. Data were analysed by a one-way analysis of variance (anova) and by Pearson's rank analysis. The institutional ethics committee approved the study, and informed consent was obtained from patients and controls.. No differences were found between CVI and the control group when comparing gender distribution, age, body weight, BMI, waist/hip ratio, relative body fat and fasting glucose levels. Leptin levels were lower (P < 0.05) in CVI patients than in controls and lower than fasting leptin levels detected in a large population study. CVI patients' serum leptin levels did not correlate with BMI (r = 0.074, P = 0.8) and their high HOMA-IR indicated insulin resistance.. CVI patients are relatively hypoleptinaemic and insulin resistant, and their serum leptin levels are not correlated to their BMI.

Topics: Adult; Body Mass Index; Common Variable Immunodeficiency; Female; Glucose; Homeostasis; Humans; Insulin; Insulin Resistance; Leptin; Male; Middle Aged