The effect of undernutrition on immunological responses to BCG and TAB vaccines in mice maintained on a natural diet

A study was made on the effect of undernutrition on the immunological responses of mice to TAB and BCG vaccines. The mice were fed a diet comprising chapati and germinated grams; one group was fed ad libitum while another was given half the quantity consumed by the first group. The undernourished mice showed a poor immune response to BCG: only 23% showed a positive reaction to foot pad challenge with purified protein derivative, compared with 76% of the well-fed mice. The mean increase in thickness of the foot pad was also significantly smaller in the undernourished mice. Antibody titres against the H and O antigens of TAB were essentially similar in both groups of mice. The results suggest that undernutrition depresses cell-mediated immune responses but not humoral responses.

Depression of T-cell function and normality of B-cell response in protein calorie malnutrition

Antibody response to a T-cell dependent antigen, sheep erythrocytes and to a B-cell mitogen, purified lipopolysaccharide (LPS), has been studied in mice kept on protein deficient (2 and 4 per cent casein) diets. The number of plaque-forming cells (PFC) to SRBC were 20-5 +/- 7-7 per million spleen cells in protein-deficient animals compared to 261-0 +/- 31-1 in parallel controls maintained on a protein rich diet (18 per cent casein). No difference was observed in number of PFC formed in controls and deficient animals to LPS, values were 161-4 +/- 19-7, 158-5 +/- 14-2, & 162-3 +/- 31-9 in control (18 per cent casein) and deficient groups (4 per cent and 2 per cent casein) respectively. The delayed hypersensitivity skin reaction to SRBC measured in foot pads was significantly lower in mice on 4 per cent casein diet compared to controls. These studies suggest that the effect of protein deficiency is primarily on T-cell function and not on the B-cell response;

Reversible cerebellocerebral disorder in primary hemochromatosis

Reversible cerebellar dysfunction is described in a patient with primary hemochromatosis. The electroencephalographic abnormalities initially recorded became normal after repeated phlebotomies. Both cerebellar dysfunction and electroencephalographic changes were present without clinical signs of hepatic failure, but may be related to the altered hepatic function tests.

Effect of vitamin A and protein-calorie undernutrition on immune responses

In rats rendered vitamin A-deficient, there was a marked atrophy of the thymus and the spleen. To a large extent, but not completely, these changes were a result of the concomitant protein-calorie undernutrition. In the thymus the cortex was depleted of lymphocytes. The number of germinal centres was reduced in the spleen. The incorporation of [³H-methyl]thymidine into DNA in cells derived from thymus and spleen of deficient animals was six times lower than in normal littermate controls. On administration of sheep erythrocytes (SRBC), the number of plaque-forming cells per million nucleated spleen cells in deficient animals was 73±6, as compared with 141±36 in normal controls. Similar observations were made on the titres of haemagglutinins and haemolysins formed in response to SRBC. The response of vitamin A plus protein-calorie-deficient animals to diphtheria and tetanus toxoid injection was poorer than the pair-fed controls. These studies demonstrate an important influence of vitamin A and protein-calorie nutrition on lymphoid organs and on immune responses.

Systemic macrophage mobilization and granulomatous response to BCG in the protein-deficient rabbit

In view of increased susceptibility to tuberculosis in protein malnutrition, the phenomenon of accelerated granulomatous response by the macrophage was studied in rabbits immunized and subsequently challenged with BCG. Dietary protein depletion resulted in marked retardation of macrophage mobilization and granuloma formation in various organs. The granulomatous index was low in most organs. The granulomas were few, small, abortive and ill-formed by loosely knit epithelioid cells and giant cells. This deficiency of macrophage function might limit the effectiveness of BCG vaccination in the malnourished host.