Long term follow-up results of 1 year MDT in MB leprosy patients treated with standard MDT + once a month Minocycline and Ofloxacin.

BACKGROUND: This study was initiated in consultation with the National Leprosy Eradication Programme (NLEP) in mid nineties to try new treatment regimens for leprosy which were more robust in terms of control of reactions, long term relapses, operationally easier to undertake and feasible in field conditions. It was also envisaged to see if the addition of newer bactericidal drugs would be beneficial. OBJECTIVES: (i) To test the feasibility, safety and response of the patients to the new regimen. (ii) To observe the incidence of reactions during and after stoppage of therapy, for a period of 8-10 years after release from treatment. MATERIALS AND METHODS: A total of one hundred skin smear positive MB patients (15 LL, 35 BL and 50 BB) patients were included in this study. All the patients received the standard MDT + once a month supervised 100 mg of Minocycline and 400 mg of Ofloxacin for 12 months during the treatment phase. Thereafter, the treatment was stopped in all the patients which were followed-up on placebo (B complex tablets). Of these, 70 patients completed the treatment schedule of one year therapy and the post treatment follow-up of 9 to 10 years. RESULTS: All the patients tolerated the drugs well. The clinical response of the patients to the treatment was very good of which 32.85% of cases had history of reactions before starting treatment. During treatment, the incidence of reactions increased marginally to 38.5%, but these were easily controlled with concurrent administration of steroids. After completion of treatment the incidence was much less i.e. 10% and 3% after 1 and 2 years of post treatment follow-up respectively. The overall relapse rate is 5.7% (4/70) with an incidence density of 0.05/100 patient years. Relapses were confirmed by clinical, bacteriological, molecular biological (rRNA probes and 36 kD targeting PCR) as well as ATP bioluminescence. The relapsed patients presented with the appearance of new lesions, slit-skin smears were again found to become positive after becoming negative. Three of the four cases who relapsed had the initial mean BI of 2 to 2.9+ whereas one had the initial mean BI of 1.5+. Also, 2 of the 4 relapsed patients had positive PCR signals at the time of stoppage of treatment. CONCLUSION: The addition of Minocycline and Ofloxacin to the standard FDT has been observed to be a well tolerated. Overall as of now, the incidence of reactions observed with the newer treatment regimen is found to be significantly lower than that of 2 years fixed duration MB-MDT. The efficacy of this regimen regarding bacteriological clearance and relapse rates could not be compared due to non-availability of the results of experience with standard 1 year MDT regimen. However, this regimen appears to be operationally feasible and safe for the users.

Chemotherapy trial in paucibacillary leprosy using clofazimine.

In a double blind study, 300 PB patients (smear negative, indeterminate, tuberculoid and borderline tuberculoid) were randomly allotted to two regimens, the control subjects (150 patients) receiving the standard WHO multidrug regimen of six doses of once a month rifampicin with daily dapsone therapy for six months, while the study group (150 patients) receiving 50 mg of clofazimine daily for six months in addition to the WHO regimen. After stoppage of therapy all the patients were followed up on placebo. The regimens were well tolerated. In 7.5% of patients on clofazimine containing regimen, the lesions showed persisting activity at the time of stoppage of therapy, compared with 16% on the control regimen. This activity subsided spontaneously, more rapidly, in the study group (80% compared with 30% in the control group) in six months. Two patients in the control group and one patient in the study group developed late reaction. There were no relapses in the study group, whereas, two patients have relapsed in the control group during a follow-up of 2.5 to 3.5 years.

Viability determination of M.leprae: comparison of normal mouse foot pad and bacillary ATP bioluminescence assay.

Correlation between viability assessment by mouse foot pad and ATP bioluminescence was studied in biopsy specimens from multibacillary leprosy cases. Biopsies were processed for inoculation into mouse foot pad and estimation of bacillary ATP levels by bioluminescent assay by earlier established procedures. ATP content as pg/million bacilli was estimated and correlation was assessed with growth in the mouse foot pad. It was observed that when the ATP content was > 36 pg/million bacterial cells, (> 1% probable viables) there was growth in the mouse foot pad from all the specimens. Similar results were observed when the ATP content was in the range of 3.6 to 35.99 pg/million cells (0.1 to 1% probable viables). The positivity rates in the mouse foot pad decreased when the ATP content decreased further. No positive growth in the specimens below 0.04 pg/million bacilli (< 0.001% viable organisms) was observed. These findings show an overall correlation between viability assessed by mouse foot pad and ATP bioluminescence. These observations validate the concept of ATP content of viable unit of M.leprae being in the order of 10(-15) g/live cell which is in the same order of magnitude as a colony forming unit of cultivable mycobacteria.

Studies on microbial aerobic flora of skin in leprosy patients.

This study reports the isolation and identification of aerobic organisms from biopsies/slit-skin smears/scrapings from 129 leprosy patients and 50 healthy controls. These include 56 paucibacillary (PB) and 73 multibacillary (MB) cases. Thirty-six isolates from the specimens from 21 patients and 15 healthy controls were grown. The non-mycobacterial isolates from clinically PB leprosy (TT/BT/I) patients were: (1) Gram-positive cocci: Staphylococcus aureus(1), Staphylococcus albus(1); (b) Gram-positive bacilli: Bacillus subtilis(1), Corynebacterium xerosis(1); (c) Gram-negative bacilli: Escherichia coli(1), Proteus mirabilis(2), Klebsiella pneumoniae(1) and Pseudomonas aeruginosa(1). The isolates from clinically MB leprosy (BB/BL/LL) patients were: (a) Gram-positive cocci: Micrococci(1), Staphylococcus aureus(1) and Staphylococcus albus(1); (b) Gram-positive bacilli: Corynebacterium xerosis(1); Corynebacterium hofmanni(1) and Bacillus cereus(1). (c) Gram-negative bacilli: Escherichia coli(2), Klebsiella pneumoniae(1) and Proteus mirabilis(2). The specimens from healthy controls yielded similar organisms. These were (a) Gram-positive cocci: Staphylococcus albus(2), Staphylococcus aureus(2) and Micrococci(2); (b) Gram-positive bacilli: Corynebacterium xerosis(1), Bacillus subtilis(2), Corynebacterium hofmanni(1) and Bacillus cereus(1); (c) Gram-negative bacilli: Escherichia coli(3), Proteus vulgaris(1) and Proteus mirabilis(1). While these results show no significant differences in the species types of non-mycobacterial aerobic organisms isolated from healthy skin and PB/MB types of leprosy, these isolates need to be characterized by immunological/molecular methods to find out subtypes if any.

Isolation and characterization of cultivable mycobacteria from leprosy skin.

Attempts were made to isolate cultivable mycobacteria from 129 biopsies/slit-skin scrapings from the skin of leprosy patients (73 multibacillary-BB/BL/LL and 56 paucibacillary-TT/BT/I) as well as 50 healthy controls. Among the 19 isolates obtained, 17 were from specimens from leprosy cases whereas two were from healthy controls. 14 of the 17 isolates were from multibacillary cases and three were from paucibacillary patients. The mycobacteria isolated were: M.scrofulaceum (4 = all LL cases); M.avium (3 = 2 from LL cases and 1 from healthy control); M.avium-intracellulare complex (1 LL); M.gordonae (2 = 1 from BT and BB each); M.flavescens (1 BL); M.smegmatis (2 = both LL); M.phlei (4 = 1 LL, 1 BL, 1 BT and 1 healthy control); M.fortuitum (1 BL); and M.chelonei (1 BT relapse). The results of this study suggest a preferential colonization of skin of lepromatous leprosy cases by M.scrofulaceum and M.avium. As such isolates have been reported by the investigators from other parts of the world, independent confirmation of such trends in Indian patients is significant and casual relationship (if any) between such colonization and development of lepromatous disease merits further investigation.

Reduction in CD1 positive epidermal Langerhans cell numbers in leprosy lesions following epicutaneous application of 2:4 dinitrochlorobenzene.

A study was made on Langerhans cells (LC) in the dermal lesions of leprosy after epicutaneous application of 2:4 dinitrochlorobenzene (DNCB) to the lesion. LC were quantitated with OKT6 monoclonal antibody and indirect immunofluorescence. A depletion or reduction in the numbers of CD1+ epidermal LC was observed at both 4 and 24 hours after the application of DNCB in the lesions of both tuberculoid and lepromatous leprosy, compared to untreated lesions.

Treatment of paucibacillary leprosy with a regimen containing rifampicin, dapsone and prothionamide.

Ninety paucibacillary leprosy patients having indeterminate (I), tuberculoid (TT) and borderline tuberculoid (BT) type of leprosy with bacterial index (BI) of less than two on the Ridley scale were treated with rifampicin (RFM) 600 mg once a month, dapsone (DDS) 100 mg daily and prothionamide (PTH) 250 mg daily. Treatment was stopped at the end of six months. The patients tolerated the drugs fairly well and in only two patients the drugs had to be stopped (in one due to jaundice and in the other due to gastric intolerance). About 6% of patients had early reactions which subsided with additional steroid therapy. The inactivity rate was 60% at six months and this improved to 96% at 12 months. No cases of late reactions and relapses were encountered in the limited follow-up period of six months; and a longer follow-up is necessary for ascertaining the relapse rates. The preliminary results however suggest that the addition of prothionamide to the standard WHO paucibacillary regimen is well-tolerated with increased inactivity rate and fewer instances of late reactions.

Histological changes with combined chemotherapy and immunotherapy in highly bacillated lepromatous leprosy.

Highly bacillated untreated lepromatous cases with an initial BI 4+ of to 6+ were treated with combined multidrug treatment (MDT) and immunotherapy with heat killed Mycobacterium w or BCG. The vaccines were administered intradermally every six months. It was observed that majority of cases on immunotherapy showed increased lymphocytic infiltration (both at local and distant sites) and some cases showed epithelioid cells as well. The lymphocytic infiltration was (slightly) more vigorous in those vaccinated with Mycobacterium w. Such changes were not seen in the patients on MDT alone. Also, the granuloma fraction reduced much faster in cases who were on additional immunotherapy as compared to those on MDT alone. These changes along with evidence of clinical and bacteriological improvements suggest that immunotherapy may have an important supportive role specially in the therapy of anergic lepromatous cases.

Clinical and bacteriological progress of highly bacillated BL-LL patients discontinuing treatment after different periods of MDT.

Highly bacillated lepromatous patients (BL/LL) with an initial bacterial index (BI) of 4 to 6+ are being treated with a modified World Health Organization-recommended multiple-drug therapy (WHO/MDT) regimen consisting of rifampin 600 mg once a month, clofazimine 100 mg on alternate days, and dapsone 100 mg daily. The clinical and bacteriological profiles of the patients who had discontinued treatment at different durations have been compared with patients who took the same treatment until attainment of smear negativity. All six of the patients who had discontinued treatment at 12-18 months had worsened clinically and bacteriologically, and viable bacilli could be demonstrated in those tested for ATP. In four patients who had stopped treatment at 24-30 months, the BI continued to fall and there was no clinical or bacteriological worsening in 1 to 2 years of follow-up. The fall in the BI in five cases who had discontinued treatment at 36-44 months was comparable to those on continuous treatment, and there was no worsening. These observations indicate that with the conventional MDT regimen it is not advisable to stop treatment at 12 and 18 months. It appears that treatment should be continued for at least 2 years, and longer in the untreated highly bacillated cases. Prospective clinical trials with a sufficient number of cases and long-term follow-up need to be carried out to ascertain the optimum duration.

CD1-positive epidermal Langerhans cells in skin reactions to autologous peripheral-blood-derived mononuclear cells in leprosy patients.

A comparison was made on the characteristics of the infiltrates, the number and distribution of CD1-positive epidermal Langerhans cells (LC) at the sites of skin reaction induced by autologous peripheral-blood-derived mononuclear cells (PBMC) in leprosy patients. Clinically and histologically, the skin reaction was well expressed in tuberculoid patients as compared to lepromatous patients, erythema nodosum leprosum (ENL) patients and contacts. The quantum of lymphocytes in the infiltrates was maximal in the tuberculoid patients and it was minimal in lepromatous and ENL patients. The number and distribution of LC in the tuberculoid patients was significantly higher in the PBMC-inoculated sites as compared to control sites over 24 h. In contrast, no difference in the number and distribution of LC was noticed in the lepromatous and ENL patients. These observations indicate that the lymphocytes of tuberculoid patients in contrast to lepromatous leprosy patients are capable of sustenance in the local micro-environments of the skin and an effective interaction may be possible between LC and PBMC.

CD1 positive epidermal Langerhans cells in indeterminate leprosy.

Langerhans cells (LC) in the skin lesions of 10 untreated indeterminate leprosy patients were defined by indirect immunofluorescence using monoclonal antibodies. No difference was observed in the numbers and distribution of epidermal LC in the indeterminate lesions and controls. However, the infiltrates of these lesions contained CD1+ cells. Most cells in the infiltrates HLA DR antigens.