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Biomedical subjects

K Saha

Publications and source records attributed to K Saha.

At least 163 records · Page 9Linked to original sources

Immune deficit in patients with lepromatous leprosy: its nature and relation to genetic factors, spectrum, and duration of the illness.

Cell-mediated immunity or hypersensitivity to M. leprae and other unrelated antigens, such as tuberculin and dinitrochlorobenzene, was studied in 73 leprosy patients of different histopathologic types. It was found that specific as well as nonspecific anergy intensified as the disease spectrum shifted from the tuberculoid toward the lepromatous immunologic pole. Within the lepromatous group, the impairment of cellular immunity became more pronounced as the bacillary load increased. It was found that the impairment of the cell-mediated immunity towards antigens other than M. leprae became more severe as the duration of the illness increased. Late lepromin responsiveness, which is the hallmark of resistance of an individual to M. leprae, may be absent even before the onset of clinical illness. Its deficit seems to be primary and has a genetic predisposition.

Adult↗

Gut-associated IgA deficiency in lepromatous leprosy.

Sera, intestinal secretions and intestinal biopsies were collected from twelve biopsy-proved lepromatous leprosy patients with the help of a capsule invented by Roy Choudhury. Sera from another twenty-five proved lepromatous cases were also included. Sera and intestinal aspirates from twenty-five normal subjects and twenty patients with intestinal tuberculosis were also taken as controls. Acid-fast organisms, morphologically resembling Mycobacterium leprae, were detected in the intestinal aspirates of only two leprosy patients. Immunoglobulin levels in their sera and elevation secretions were estimated by the single radial immunodiffusion technique. Significant elevation of serum IgG, IgA and IgM, selective IgA deficiency in intestinal aspirates and flattening of intestinal villi along with mononuclear cell infiltration were conspicuous observations in the leprosy group. On the other hand, the patients with intestinal tuberculosis showed elevation of the IgG level in serum as well as in the intestinal secretions. It was postulated that persistent challenge by M. leprae or its antigens to the IgA immunocytes of the intestinal epithelium might have induced tolerance leading to IgA deficiency and subsequent subtotal atrophy of the intestinal villi in the patients with lepromatous leprosy.

Adult↗

An attempt at passive transfer of immunity to leprosy patients by transfusion of allogeneic lymphocytes, inactivated with mitomycin C.

An attempt was made to repair cell-mediated immunity in 7 patients suffering from lepromatous leprosy and severe erythema nodosum leprosum by intravenous infusion of 400 million allogeneic blood lymphocytes on 3 occasions. The lymphocytes were obtained from lepromin and tuberculin-positive subjects and were inactivated in vitro by treatment with mitomycin C. Immunotherapy with inactivated lymphocytes only modified the severity of erythema nodosum leprosum, without altering other aspects of the disease.

Blood Transfusion↗

Biological variation of immunoglobulin concentrations in normal human tears related to age and sex.

Single radial immunodiffusion method was used to measure the concentration of IgG, IgA, IgM and IgD in tears of 220 healthy individuals aged from 2 to 86 years. Relation of the values to age and sex has been evaluated statistically by regression analysis method. Mean IgA level was 30.7 mg/100 ml. IgG could be detected in 200 samples and the level was less than 1 mg/100 ml. IgM was detected in only 7 samples and the value was less than 1 mg/100 ml. IgD could not be detected in any of the sample. The IgA level in males and that in females differs significantly, the females having a higher mean value. The IgA level appears to increase in both sexes with age. No relationship with age and sex could be established in other types of immunoglobulins.

Adolescent↗

Serum immunoglobulin and complement levels in tropical pulmonary eosinophilia, and their correlation with primary and their relapsing stages of the illness.

Serum concentrations of IgA, IgG, IgM, IgE, C3 and C4 complement components were estimated in 19 patients with tropical pulmonary eosinophilia (TPE). Thirteen of the patients presented during their first episode of TPE and 6 of them during a relapse of the disease. We found a remarkable elevation of serum IgE level in TPE, which is consistent with earlier reports. In contrast, there was a modest increase in IgM levels and unchanged or even lower levels in IgA and IgG immunoglobulin classes. There seemed to be a direct relationship between IgE level and degree of peripheral blood eosinophilia in TPE. The outstanding finding, however, was a nearly threefold higher mean serum IgE level in patients with relapsing disease as compared to that observed in patients during the primary attack. This is the first reported study of circulating complement components in TPE. A significant rise of serum C3 level was found in these patients; there was no similar elevation of serum C4 component.

Adolescent↗

Undernutrition and immunity: smallpox vaccination in chronically starved, undernourished subjects and its immunologic evaluation.

This study illustrates the specific immune response of chronically starved, undernourished adults after inoculation of live smallpox vaccine. It produced no adverse effect, and major vaccinial reaction was observed in all. 63% of undernourished individuals showed a fourfold or greater rise of the neutralizing antibody titre. In contrast, only 9% of normal healthy subjects could show similar response. However, the prevaccination titre was much lower in the undernourished group than in the control group, and the postvaccination titre also remained persistently lower in the former than in the latter group. Furthermore, whereas the specific humoral antibody response in the undernourished subjects was partially adequate, the development of specific cellular immunity against vaccinia was remarkably poor, indicating that smallpox vaccination in these subjects might be less effective against variola infection. This observed profound effect of chronic starvation and severe undernutrition on the immune apparatus was possibly multifactorial, protein depletion being the most important factor, as proved by the significantly low serum albumin level. The significantly low peripheral blood lymphocyte count and spectacular unresponsiveness to many antigens in these individuals suggested profound depression of the thymolymphatic system. Further, the significantly low level of neutralizing antibody in the malnourished subjects suggested that the formation of this protective antibody might necessitate the cooperation of T lymphocytes.

Adult↗