Observations on reactions of leprosy in the field.

In order to assess the incidence of reaction in leprosy, it would be necessary to examine the data from a field control unit. In this study, it was found, at a fully monitored control unit, that Type I reaction occurred in 3.9% of borderline cases and Type II in 23.7% of LL and BL cases. Even so, the load of reaction is not high since reaction of Type I and Type II together are seen only in 3.7% of all types of cases. A majority of them are of mild or moderate degree and could be treated as out-patients. Of the borderline cases, the BB type showed maximum rate of reaction. The BL type can present with both Type I and Type II reactions with a total incidence of 12.8%. While the BT type constituted 74% of total cases, reaction of Type I occurred in 3.1% of cases. Reaction also occurred in 0.8% of RFT cases.

Reactions in borderline leprosy.

This is a retrospective study of 276 patients consisting of 157 active and 119 reactive patients of borderline leprosy. They were followed up for 10 years after sulphone monotherapy. The presenting symptoms were carefully examined from the records and systematically presented. Frequency of reactions was least in BT cases and most in BL cases. Risk factors of reaction appear to be the type of leprosy, multiplicity of lesions, high BI and, possibly, psychological stress. Biopsy of skin lesions was performed in all cases initially, and at the subsidence of the disease. Histological findings closely correlated with clinical classification. While all the cases showed clinical subsidence, histological subsidence was found in 200 (73%) cases, and the condition was static in 36 cases (13%). Immunological upgrading was seen in 110%, while 4% showed downgrading. Bacteriological status and lepromin reaction of active and reactive cases were compared. All these factors need to be taken into consideration for instituting prompt and proper treatment.

Correlation of clinical, histological and immunological features across the leprosy spectrum.

The Ridley-Jopling system of classification of the variegated clinical pattern of leprosy is based on the specific cell-mediated immunity observed in the histopathology of skin lesions conforming to a spectrum from TT at one end to LL at the other. In this study a fairly large sample of 90 patients was classified on clinical grounds; the histopathology of the skin lesions was studied blind. There was an overall concordance of 90% between the clinical and histological classifications. In addition, the systemic cell-mediated and humoral immune responses were studied. The in vivo cell-mediated immune response, namely the Mitsuda skin response, mostly conformed to the clinical classification. While the in vitro lymphoproliferative responses to BCG and its sonicate were high, the lymphoproliferative responses to Dharmendra lepromin were surprisingly poor. Humoral responses to 35 kDA protein of M. leprae and PGL-1 were good in most LL, BL patients and tapered off towards TT. IgG antibodies to recombinant ML 65 kDa proteins denoted mycobacterial presence.

Poor correlation of systemic immunological parameters with clinical features in macular leprosy.

On the basis of clinical features and bacteriological status, macular skin lesions of nine cases of leprosy were classified as falling within a spectrum between the tuberculoid at one end and the lepromatous at the other. While histologic correlation was seen in 60% of cases, humoral and cellular systemic immunologic features were found to be uncharacteristic. It is suggested that macular lesions form an early stage in the development of leprosy where the systemic immunological response is yet to set in fully.

Detection of S-100 antigen and anti ceramide antibody in sera of leprosy patients with and without reaction.

Levels of anticeramide antibodies and S-100 antigen in leprosy patients with and without reaction are compared in this study. The increase in levels of IgM anti ceramide antibody in the tuberculoid group of patients with reaction, when compared to those without reaction, is significant (P < 0.05). Similarly, significant increase (P < 0.01) was observed in the borderline group with reaction. No significant change in anti ceramide antibody level was observed in the lepromatous group of patients with and without reaction. Mean levels of S-100 were slightly lower in all three groups of patients with reaction, but the differences were not statistically significant.

Histological and immunological correlates of suspected leprosy lesions.

Thirty-two subjects with suspected leprosy lesions were investigated to assess various modalities of sensibility and sweat function and these were correlated with immunological and histological parameters. It was found that pain and temperature, mediated by small unmyelinated fibres were impaired in the early lesions. Impairment of sweat function was seen only when one of the modalities of sensibility was also affected. Antibodies specific to a protein (35 kDa) antigen and phenolic glycolipid 1 of Mycobacterium leprae were positive in nine and 12 cases respectively, while 15 of the 31 biopsies revealed the presence of mycobacterial antigens in these lesions. The implications of these findings are discussed.

Clinical and electroneurophysiological assessment of leprosy patients on dapsone monotherapy--a two year follow-up study.

Fifty-three persons with tuberculoid type of leprosy having a thickened nerve on one side and a clinically normal nerve on the contralateral side were studied before, during and after two years of therapy for electrophysiological abnormalities in apparently normal and in obviously thickened nerves. Twenty-seven patients had received treatment with dapsone 100 mg orally and 26 cases had received rifampicin therapy. It was found that there was no extension of anesthesia or diminution of motor power over a period of two years. There was no significant difference between the initial and final recordings of motor and sensory nerve conductions if aggregate figures were taken. However, taking individual cases, deterioration in nerve conduction (increased latency and decreased velocity) was found in two patients, of whom one had received dapsone and the other had received rifampicin.

Reliability of direct skin smear microscopy in leprosy.

Skin smear direct microscopy is an important tool for diagnosis of leprosy. The study was planned to understand the reproducibility of skin smear reading by a trained technician. Skin smears were collected from known patients of leprosy from the field area. They were stained for acid fast bacilli following the standard cold staining procedure and were read following the Ridley scale. A sample of smears was re-examined on two occasions by the same technician, following blind procedure. There was a systematic under reading on the second occasion, which was attributed to the defective storage of the slides. However, the agreement between second and third examinations was very good (Concordance 81.34%, Kappa 0.74). The finding was confirmed on a repeat examination. It can be concluded that the Direct Skin Smear Microscopy is a reliable and reproducible technique under experimental conditions.

Evaluation of the efficacy of candidate vaccines against M. leprae infection in mice.

Delayed-typed hypersensitivity (DTH) response and protection value of some of the candidate vaccines alone and in combination with BCG has been investigated. It was observed that both M.w. and BCG gave heightened DTH and good protection. On the other hand both M. leprae and ICRC evoked moderate DTH and gave poor protection. However on combining any of these candidate vaccines with live BCG, the lowering of DTH and poor protection was observed except in the M. leprae combination which in spite of low DTH gave better protection.