concanavalin-a and beta-Thalassemia

Nutritional deficiencies have been variably observed in thalassaemia and the aetiology of many of the immune abnormalities in thalassaemic children are poorly defined. Therefore, we tested the hypothesis that certain immune abnormalities have a nutritional basis. Nutritional status, selective quantitative and functional indices of immunity were studied in twelve children (7 females, 5 males; mean age 28 months, SD 5 and range 19.8-35.5), with thalassaemia major before and after a one month period of intensive nutrition support (the study diet consisted of 'Enfapro' liquid formula (Mead Johnson) with added dextrose and corn oil to achieve a caloric density of 1.1 kcal/cc in addition to vitamins and minerals). Each child was provided approximately 150 kcal/day and 4 g of protein/day. Lymphocyte proliferation to Concanavalin A (Con A) (P = 0.008) and Purified Protein Derivative (PPD) (P = 0.002) was depressed upon entry into the study, however the response to Con A attained normal values by the end of the intervention. Compared to baselines, the proliferative response to Con A (P = 0.005) and Phytohemagglutinin A (PHA) (P = 0.031) both improved after the nutrition support. Although there was no general correlation of zinc status with lymphocyte proliferation, normal baseline zinc status was associated with improvement of proliferation. The %CD4 increased (P = 0.036), primarily because of a decrease in total lymphocytes and to lesser extent a decrease in CD8 lymphocytes. Serum immunoglobulin concentrations were found to be elevated on admission but were not significantly affected by the nutrition intervention. C3 concentrations were uniformly depressed on admission but increased by the end of the study protocol (P = 0.037). C4 and CH50 activity were not significantly influenced by the intervention. In conclusion, children with beta thalassaemia have abnormalities of lymphocyte function as well as key complement components that are responsive to nutrition support. In addition, zinc status appears to have an important role in lymphocyte function in these children.

Topics: Anthropometry; beta-Thalassemia; Child Nutrition Disorders; Child, Preschool; Complement System Proteins; Concanavalin A; Female; Food, Formulated; Humans; Immunoglobulins; Infant; Lymphocyte Activation; Lymphocyte Count; Lymphocyte Subsets; Lymphocytes; Male; Nutritional Status; Thailand; Zinc

Lymphocyte subpopulations and proliferative responses to mitogens of 24 beta-thalassemia/HbE patients were studied and compared with those of 23 healthy controls. Results of the study were analyzed in correlation with clinical aspects i.e. severity of disease (anemia), frequency of infections and iron status. T(CD3+) lymphocytes were found to increase in thalassemic patients compared to normal controls. The CD4+ or CD8-positive lymphocytes and CD4/CD8 ratio were not statistically different from normals. Without mitogen, lymphocytes from thalassemic patients incorporated more [3H]Tdr than those from normal controls. Stimulation index (SI) of these cells after various mitogens were lower than in normal subjects. The observations were more obvious in patients with severe disease (severe anemia) and those who had frequent infections. These findings suggest that lymphocytes from thalassemic patients are activated in vivo. Whether these cells are less efficient in response to new or previously unexposed antigens remains to be proven.

Topics: Adolescent; Adult; Antigens, Bacterial; beta-Thalassemia; Concanavalin A; DNA Replication; Female; Hemoglobin E; Hemoglobinopathies; Humans; Immunophenotyping; Lymphocyte Activation; Lymphocyte Count; Lymphocyte Subsets; Male; Middle Aged; Mitogens; Phytohemagglutinins; Pokeweed Mitogens; Streptococcus