|Year : 1989 | Volume
| Issue : 1 | Page : 24-9
Immunoprofile of pulmonary tuberculosis-comparison with normal healthy controls.
GG Bhave, AV Pathare, CC Dagha, LL Chabria, SG Dalvi
G G Bhave
The immunoprofile of 60 adult patients of pulmonary tuberculosis was studied and compared with 22 normal controls. The immunological parameters studied were serum protein electrophoresis, serum immunoglobulins (IgG, IgA and IgM), delayed hypersensitivity by Mantoux test, and T-cell % estimation. The mean total serum proteins and serum albumin were significantly lower, whereas mean beta and gamma globulins were elevated. Mean serum IgG and serum IgA showed a significant rise, whereas the T-cell % was significantly reduced when compared to controls. The significance of these findings is discussed.
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Bhave G G, Pathare A V, Dagha C C, Chabria L L, Dalvi S G. Immunoprofile of pulmonary tuberculosis-comparison with normal healthy controls. J Postgrad Med 1989;35:24-9
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Bhave G G, Pathare A V, Dagha C C, Chabria L L, Dalvi S G. Immunoprofile of pulmonary tuberculosis-comparison with normal healthy controls. J Postgrad Med [serial online] 1989 [cited 2022 Dec 4 ];35:24-9
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Tuberculosis in India has been widely studied in the last two decades by various surveys. The incidence of infection in India is 2-4%, incidence of disease i.e. bacteriologically confirmed disease is 4 per 1000 population, and the prevalence of infection is as high as 40% Also, the disease is capable of manifesting in more than one morphologic and/or clinical forms, the commonest being pulmonary involvement.
There is very little data available on the immunoprofile in patients with tuberculosis in India.,, In the recent years, with the advent of sophisticated immunological tools and techniques, immunology of tuberculosis has become a subject of growing interest. According to Youmans immunity to tuberculosis is of cell mediated type. Specific immunity, is characterised by intramacrophagic bacteriostasis rather than intracellular killing. Thus, it seems that call mediated immunity plays an important role against facultative intracellular parasites like Mycobacterium tuberculosis. We, therefore, undertook this study, in patients of pulmonary tuberculosis to evaluate their humoral and cell mediated immunity by doing certain preliminary investigations like serum immunoglobulin estimations, serum protein electrophoresis, T-cell % and Mantoux test to assess delayed hypersensitivity.
MATERIAL AND METHODS
The clinical material consisted of 60 adults suffering from pulmonary tuberculosis with ages varying from 15 to 60 years, of which 51 (85%) were males and 9(15%) females. They were studied and compared to 22 age and sex matched normal, healthy volunteers, in whom antecedent history of respiratory tract infection was ruled out prior to entry into the study. All patients were subjected to a thorough clinical examination. Sputum samples were studied by smear and culture for demonstration and isolation of Mycobacterium tuberculosis. The sputum sample was concentrated using ether-flotation technique. The concentrate so obtained was then used for preparing smears which were stained, by Ziehl-Neelsen's method. Cultures were made on Lowenstein-Jensen media and were incubated for 6-8 weeks. The diagnosis of pulmonary tuberculosis was established by positive smear and/or culture in 48 patients, whereas in the remaining 12 patients where bacteriology was negative, typical radiological features were relied upon.
Blood was also collected for the estimation of serum immunoglobulins by the single radial immuno-diffusion technique of Mancini et al. Serum protein electrophoresis was done on starch gel by the slide method, using bicarbonate buffer at pH of 8.6. Total protein concentration was determined by the biuret method of Weichselbaum. T-cell % was estimated by separating lymphocytes from venous blood by density-gradient centrifugation and identifying them under the microscope by their capacity to form rosettes with sheep RBCs. Mantoux test was performed by giving 5 tuberculin units intradermally, (equivalent to 0.001 mg of PPD). The reaction was read in millimeters of induration, at the end of 72 hours by measuring with a caliper at right angles to the long axis of the arm as per recommendations of the Diagnostic Standards and Classification of Tuberculosis, National Tuberculosis and Respiratory Diseases Association.
Statistical parameters: Mean and standard deviations were computed for each variable. To determine the significance of variance, Student's 't' test was applied. A p value of 0.05 or less was considered significant.
The results are tabulated as shown below. [Table 1]shows the significance of variation between the two groups, patients v/s controls, when comparing immunological parameters namely, serum immunoglobulins and T-cell %. The mean serum IgG and IgA were significantly elevated, whereas the T-cell % was significantly reduced in the patient group as compared with the controls. [Table 2]shows the comparison of serum protein electrophoresis in the two groups. Total serum proteins, serum albumin and serum alpha globulins were significantly reduced, whereas serum beta and gamma globulins were significantly elevated in the patient group as compared with the controls.
[Table 3]and [Table 4] show the comparison of Mantoux positive with Mantoux negative patients with respect to serum immunoglobulins, T-cell % and serum protein electrophoresis respectively. The test is said to be positive if at the end of 72 hours the diameter of skin thickening measures 10 mm or more, insignificant if it is between 6-9 mm and negative if it is less than 5 mm. Of the 60 patients studied, 50 (83% showed a positive reaction, whereas the remaining 10 (17%) patients showed either insignificant or negative reactions. Nevertheless, there was no significant variation in any of the immunological parameters studied between the two groups of patients.
The increase in the mean serum IgG observed in patients with pulmonary tuberculosis suggest that an immunological response is involved, although the antigens responsible for this response are not well understood. Experimental work of Daniel and Baum suggest that probably this response is due to the purified protein derivative, nevertheless, antibodies against polysaccharides, phosphatide fraction and other protein fractions are well known. The high levels of mean serum IgA in these patients is not surprising, considering the fact, that this is the most abundant, naturally occurring antibody which is responsible for immune surveillance of the secretory surfaces. The insignificant rise of mean serum IgM in our patients [Table 1]was also expected considering the fact, that current evidence points to immunity against tuberculosis as being of cell mediated type., The rise of serum IgM, as observed by some workers,1, probably represents secondary, superadded bacterial or fungal infection, that these patients are so prone to develop.
T-cells are the key cells with respect to cell mediated immunity. In our study, it was seen that the T-cell % was remarkably lower in the patient group [Table 1]. Bhatnagar et al found that T-cell % is mildly affected by recent tubercular infections. Malaviya et al observed that the T-cell % is considerably reduced in severe generalised or disseminated forms of tuberculosis. Whether this T-cell suppression is primary or secondary is still unclear, however, if it is the primary process, then it may predispose to the development of a more generalised disease. It also implies that the degree of T-cell suppression is directly correlated to the severity of infection and to the degree of susceptibility of the host.
The significance of delayed hypersensitivity in tuberculosis as protective immunity has been widely discussed., Although the association between delayed hypersensitivity and immunity in tuberculosis was first noticed almost a century ago, the nature of their relationship remains elusive. One view is that immunity and hypersensitivity are coincidental events, whereas, Youmans stresses that although both these processes are mediated by T-cells, they are entirely two separate entities, mediated by two different subsets of T-cells in response to the various components of the tubercle bacilli. Interestingly, in our study, we found no statistically significant change in the T-cell % of the patients who showed a positive intradermal skin test indicative of delayed hypersensitivity, compared to those patients who showed a negative skin test [Table 3] This suggests that analysis of T-cell subsets, helper-suppressor ratios etc. might have thrown more light rather than just estimation of the T-cell percentage. However, compartmentalisation of the sensitised lymphocytes in the body is also another possible explanation for the above observation.
Malnutrition is known to cause suppression of delayed hypersensitivity. In our study, the serum protein levels were remarkably low and their levels did not change significantly, when compared with patients who were Mantoux positive along with those who were Mantoux negative[Table 4]. This observation suggests that malnutrition, probably had no role to play in the outcome of the Mantoux test in our patients.
Our study confirms that cell mediated immunity has a definite role in immunity against tuberculosis. However, this being a preliminary study of the immune status in patients with pulmonary tuberculosis, confirmation of these observations with a more detailed assessment of the cell mediated immunity by estimating the T-cell helper suppressor ratio, lymphoblastoid transformation of the T-cells to specific mitogenic stimulus from antigens of mycobacterium tuberculosis and lymphocyte migration inhibition test is to be undertaken in the future projected studies.
We thank the Dean, Seth G.S. Medical College and K.E.M. Hospital, Bombay, for permission to publish this paper.
|1||Bhatnagar, R., Malaviya, A. N., Narayana, S., Rajgopalan, P., Kumar, R. and Bharadwaj, O. P.: Spectrum of immune response abnormalities in different clinical forms of tuberculosis. Amer. Rev. Resp. Dis., 115: 207-212, 1977.|
|2||Daniel, T. M. and Baum, G. L.: The immunoglobulin response to tuberculosis: I. Molecular characterization of hemagglutinating antibody to tuberculo polysaccharide in sera from patients with tuberculosis, Amer. Rev. Resp. Dis., 98: 677-680, 1968.|
|3||Edelman, R., Suskind, R., Olson, R. E. and Sirisinha, S.: Mechanisms of defective cutaneous hypersensitivity in children with protein-calorie malnutrition. Lancet, 1: 506-508, 1973.|
|4||Eichenwald, H. F.: Tuberculosis. In, "Nelson Textbook of Pediatrics". 12th Edition, R. E. Behrman, V. C. Vaugam and W. E. Nelson, W. B. Saunders Company, Philadelphia, 1983, p. 711. |
|5||Faulkner, J. B., Carpenter, R. L. and Patnode, R. A.: Serum protein and immunoglobulin levels in tuberculosis. Amer J. Clin. Pathol., 48: 556-560, 1967.|
|6||Jain, V. K., Bishnoi, H. S., Beniwal, O. P. and Misra, S. N.: Immunoglobulin profile in pulmonary tuberculosis. J. Postgrad. Med., 30: 80-84, 1984.|
|7||Jha, V. K., Bajpai, B. K. and Gupta, R. M.: Levels of serum immunoglobulins in pulmonary tuberculosis patients. Ind J. Chest Dis., 16: 361-367, 1974.|
|8||Jondal, M., Holm, G. and Wigzell, H.: Surface markers on human T and B lymphocytes. I. A large population of lymphoid forming nonimmune rosettes with sheep red blood cells. J. Exp. Med., 136: 207-215, 1972.|
|9||Laurell, C. B.: Quantitative estimation of proteins by electrophoresis in agarose gel containing antibodies. An. Biochem., 15: 45-52, 1966.|
|10||Lefford, M. J.: Editorial-Delayed hypersensitivity and immunity in pulmonary tuberculosis. Amer. Rev. Resp. Dis., 111: 243-246, 1975.|
|11||Mackaness, G. B.: The immunology of antituberculous immunity, Amer. Rev. Resp. Dis., 97: 337-344, 1968.|
|12||Malaviya, A. N., Sehgal, K. L., Kumar R. and Dingley, H. B.: Factors of delayed hypersensitivity in pulmonary tuberculosis. Amer. Rev. Resp. Dis., 112: 49-52, 1975.|
|13||Mancini, G., Carbonara, A. O. and Heremens, J. F.: Immuno-chemical quantitation of antigens by single radial immuno-diffusion. Immunochemistry, 2: 235-254, 1965.|
|14||Park, J. E. and Park, K.: Tuberculosis In, "Textbook of Preventive and Social Medicine". 11th Edition. Messrs Banarsidas Bhanot, Jabalpur, 1986, p. 164-178. |
|15||Rammurthi, G.: A Comparison of methods for the concentration and culture of acid fact bacilli in lymph nodes. M.D. Thesis, University of Bombay, 1986, pp. 23-24.|
|16||Schlossman, S. F., Levins, H. A., Rocklin, R. E. and David, J. R.: The compartmentalisation of antigen-reactive lymphocytes in desensitised guinea pigs. J Exp. Med., 134: 741-744, 1971.|
|17||Takahashi, Y., Mochizuki, K. and Nagayana, Y.: The behaviour of three different kinds of antibodies in tuberculosis: Antiprotein, antipolysaccharide and antiphosphatide II. Human tuberculosis. J. Exp. Med., 114: 569-579, 1961.|
|18||Weichselbaum, T. E.: An accurate and rapid method for the determination of proteins in small amounts of blood, serum and plasma. Amer. J. Clin. Pathol., Tech, Sect. suppl., 10: 40-49, 1946.|
|19||Youmans, G. P.: Editorial-Relations between delayed hypersensitivity and immunity in tuberculosis, Amer. Rev. Resp. Dis., 111: 109-118, 1975. |