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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of vitamin A deficiency and Newcastle disease virus (NDV)-infection on peripheral blood lymphocytes (PBL) was studied by differential cell counting and flow cytometry. Day-old chickens were fed purified diets containing either marginal or adequate levels of vitamin A and at 26 days of age half of the chickens in each group were infected with NDV. The absolute numbers of PBL and their subpopulations were studied until 10 days after infection. Vitamin A deficiency resulted in significantly lower numbers of PBL throughout the experiment. NDV-infection produced lymphopenia during the first 3 days, followed by a strong increase in PBL numbers after 6 days. Both changes in PBL were less pronounced in vitamin A-deficient birds. For flow cytometric analysis monoclonal antibodies reacting specifically with B-cells or a subpopulation of T-cells were used. Vitamin A-induced lymphopenia could be attributed to a decreased number of PBL, negative for both antibodies, and to the absence of an increase in B-cells which normally occurs at this age. The negative cells are suggested to represent, at least partially, cytotoxic T-cells, which may explain the impaired cytotoxic T-cell-activity found in earlier studies. NDV-induced lymphopenia and subsequent increase of PBL could be attributed to all cell types investigated. However, in vitamin A-deficient birds negative cells did not show these reactions. Therefore, it can be concluded that vitamin A deficiency has a detrimental effect on PBL, negative for both antibodies used, and on the normal growth of the number of B-cells at this age.
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PMID:Effects of vitamin A deficiency and Newcastle disease virus infection on lymphocyte subpopulations in chicken blood. 157 Jun 76

The effect of vitamin A deficiency in the presence or absence of Newcastle disease virus infection (NDV, La Sota strain) on weight of lymphoid organs and on the number and type of circulating white blood cells (WBC) was investigated in chickens. Day-old chickens with limited vitamin A reserves were fed purified diets containing either marginal (ad libitum) or adequate (pair-fed) levels of vitamin A and at 21-28 days of age; half the chickens in each group were infected with NDV. Vitamin A deficiency resulted only in significantly lower absolute and relative weights of bursa of Fabricius and after infection both weights of bursa and thymus were significantly lower. Relative weight of spleen was significantly higher after infection irrespective of vitamin A status. Liver weights were not affected by vitamin A status and/or NDV infection. Both vitamin A deficiency and NDV infection resulted in lymphopenia, while the lowest number of WBC were observed in vitamin A-deficient chickens during the acute phase of NDV (5 days after infection). Subsequent to lymphopenia due to NDV infection, a marked lymphocytosis was observed in controls and to a lesser extent in vitamin A-deficient birds. These results indicate that vitamin A deficiency, which is aggravated by concomitant NDV infection, affects lymphoid cell systems.
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PMID:Changes in lymphoid organs and blood lymphocytes induced by vitamin A deficiency and Newcastle disease virus infection in chickens. 177 59

Treatment with high dose vitamin A has recently been recommended for children with measles in communities where vitamin A deficiency is a recognized problem. However, the relationship between vitamin A and measles mortality has not been clearly established. We studied serum vitamin A levels in 283 children less than or equal to 5 years of age admitted to Mama Yemo and Kalembe Lembe Hospitals in Kinshasa, Zaire, between January and March, 1987. Vitamin A levels were determined by high performance liquid chromatography. Vitamin A levels ranged from less than 5 to 63 micrograms/dl (median, 8). The overall case-fatality rate was 26 per cent. On univariate analysis, age less than 24 months, pneumonia on admission, lymphopenia (less than 2000/mm3), and lower vitamin A levels were associated with death during hospitalization. In a multivariate logistic regression model, a vitamin A level less than 5 micrograms/dl was associated with fatal outcome for children younger than 24 months old (relative risk = 2.9, 95 per cent CI 1.3, 6.8), but not for older children. Further studies are needed to determine whether low vitamin A levels predispose children to severe measles and the role of vitamin A supplements in the prevention of measles mortality.
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PMID:Vitamin A levels and mortality among hospitalized measles patients, Kinshasa, Zaire. 275 67