Antigens of Mycobacterium leprae in the cerebrospinal fluid of leprosy patients: detection by monoclonal-antibody-based sandwich immunoradiometric assay and avidin/biotin immunoblotting.

Mycobacterium leprae antigens could be detected in the cerebrospinal fluid (CSF) of patients with leprosy, using a monoclonal-antibody-based sandwich immunoradiometric assay (SIRMA). Antigens of 12 kD, 35 kD and 30-40 kD were detected using ML06, ML04, and ML34 monoclonal antibodies, respectively. The 30-40-kD polysaccharide antigen, although present in larger amounts in M. leprae than the 12-kD and 35-kD protein antigens, was found in the CSF of comparatively fewer subjects. The antigen capture assay has been found sensitive to the level of nanograms. Avidin-biotin-based immunoblotting using pooled leprosy sera detected a larger number of antigens than using anti-M. leprae antisera raised in rabbits. The immunoblotting of CSF samples revealed about three antigens in the region of 100-160 kD and three more in the region of 45-60 kD as probed by leprosy sera. This study has for the first time revealed the presence of M. leprae antigens in the CSF of leprosy patients and the probable involvement of the central nervous system in leprosy.     

Rapid, radiolabeled macrophage culture method for detection of dapsone-resistant Mycobacterium leprae.

Mycobacterium leprae cells extracted from the skin biopsies of 14 bacilliferous lepromatous patients were maintained in human-murine macrophage cultures for 3 weeks in the presence of [3H]thymidine and DDS (4,4'-diaminodiphenyl sulfone). All cultures except one containing freshly extracted viable bacilli showed significant incorporation of [3H]thymidine as compared to control cultures containing heat-killed bacilli of the corresponding strain. Six susceptible strains of M. leprae obtained from untreated, freshly diagnosed patients showed significant inhibition of the uptake of the radiolabel in the presence of 3 and 10 ng of DDS per ml per culture. Eight strains of M. leprae obtained from patients clinically suspected of DDS resistance were tested in a similar manner. These strains were also concurrently inoculated in the footpads of mice given orally 10(-2), 10(-3), and 10(-4) g of DDS per 100 g of body weight for 9 months. Concordant results were obtained by both methods: five strains were found to be resistant, one was susceptible, and one was partially resistant. Strain VIII did not incorporate [3H]thymidine in the macrophage cultures and proved to be resistant in the mouse footpad. The macrophage culture system provides a sensitive, rapid screening method for the early diagnosis of DDS resistance.     

Methotrexate-induced chemical meningitis in patients with acute lymphoblastic leukemia/lymphoma

Background:

Intrathecal methotrexate (ITMTX) is an important component in the treatment as well as prophylaxis of leukemia/lymphoma. ITMTX can cause chemical meningitis characterized by vomiting, headache, and fever lasting 2-5 days with spontaneous resolution of symptoms which differentiates this syndrome from bacterial meningitis.

Objective:

This prospective observational study was carried out to determine incidence of post-ITMTX syndrome in patients receiving prophylactic ITMTX as part of Berlin-Frankfurt-Munster (BFM) protocol.

Materials and Methods:

Patients aged 15-50 years receiving BFM 90 or BFM 95 protocol for acute lymphoblastic leukemia or lymphoblastic lymphoma were followed up for post-ITMTX syndrome, defined as vomiting, headache and fever between 38° and 39°C following ITMTX.

Results:

Thirty-three patients received a total of 297 courses of ITMTX. Of the 297 doses of ITMTX, 20 episodes (6.7%) of post-ITMTX syndrome were observed. The incidence of post-ITMTX syndrome was highest after the second dose of ITMTX (24%). The most common symptom of post-ITMTX syndrome was headache which was seen in 17 (85%) patients. Seventeen (85%) patients had vomiting, 10 (50%) patients had fever, and 4 (20%) patients had backache. Meningeal signs were present in 2 (10%) patients.

Conclusions:

Post-ITMTX syndrome is not uncommon in adult patients receiving prophylactic ITMTX for treatment of acute lymphoblastic leukemia and lymphoblastic lymphoma. Patients develop a toxic syndrome closely mimicking acute bacterial meningitis but spontaneous recovery is seen without any neurological sequelae.     

Comparative leprosy vaccine trial in south India

This report provides results from a controlled, double blind, randomized, prophylactic leprosy vaccine trial conducted in South India. Four vaccines, viz BCG, BCG+ killed M. leprae, M.w and ICRC were studied in this trial in comparison with normal saline placebo. From about 3,00,000 people, 2,16,000 were found eligible for vaccination and among them, 1,71,400 volunteered to participate in the study. Intake for the study was completed in two and a half years from January 1991. There was no instance of serious toxicity or side effects subsequent to vaccination for which premature decoding was required. All the vaccine candidates were safe for human use. Decoding was done after the completion of the second resurvey in December 1998. Results for vaccine efficacy are based on examination of more than 70% of the original "vaccinated" cohort population, in both the first and the second resurveys. It was possible to assess the overall protective efficacy of the candidate vaccines against leprosy as such. Observed incidence rates were not sufficiently high to ascertain the protective efficacy of the candidate vaccines against progressive and serious forms of leprosy. BCG+ killed M. leprae provided 64% protection (CI 50.4-73.9), ICRC provided 65.5% protection (CI 48.0-77.0), M.w gave 25.7% protection (CI 1.9-43.8) and BCG gave 34.1% protection (CI 13.5-49.8). Protection observed with the ICRC vaccine and the combination vaccine (BCG+ killed M. leprae) meets the requirement of public health utility and these vaccines deserve further consideration for their ultimate applicability in leprosy prevention.     

Three Cases of Vagal Nerve Schwannoma and Review of Literature

Schwannoma arising from the vagus is an uncommon (2–5%) benign nerve tumour. This tumour most often presents as a slow growing asymptomatic solitary neck mass which rarely undergoes malignant transformation. Definitive pre-operative diagnosis may be difficult and investigations such as FNAC have low specificity. The carotid artery and internal jugular vein may be displaced antero-laterally. Diagnosis is based on clinical suspicion and confirmation is obtained by means of surgical pathology. Surgical excision is the treatment of choice for this tumour, with recurrence being rare. We describe three cases of schwannoma involving the vagus who presented differently to our unit during past 5 years.     

Quality control tests for vaccines in leprosy vaccine trial, Avadi

All the vaccines supplied for the large scale comparative leprosy vaccine trial of ICRC bacilli, M.w, BCG plus killed M. leprae (candidate vaccines), BCG and normal saline (control arms) at CJIL Field Unit, Chennai were tested for quality control by the suppliers following the procedures laid down in the WHO protocol for killed M. leprae. Quality control for BCG was carried out at BCG vaccine laboratory as per protocol. Toxicity and sterility tests were done on all the vaccine batches/lots received. As part of the quality control, bacterial count, and protein estimation were also done. Studies showed that the bacterial content and protein concentration were comparable with the original preparations. Vaccines were free from micro-organisms, toxic materials and safe for human use. Thus the quality of all vaccine preparations was satisfactory.     

10-12 years follow-up of highly bacillated BL/LL leprosy patients on combined chemotherapy and immunotherapy

This study reports the follow-up results of 36 highly bacillated untreated BL/LL cases who were serially allocated to three treatment groups. Group I patients received a modified WHO regimen (Rifampicin 600 mg once a month supervised, 50 mg of Clofazimine and 100 mg of Dapsone daily unsupervised) and BCG 0.1 mg per dose 6 monthly; group II patients received the same multi-drug treatment (MDT) and Mw (2 x 10(8) killed bacilli per dose) 6 monthly: group III patients received the same MDT with 0.1 ml of distilled water 6 monthly and acted as a control. Treatment was continued till smear negativity. All these three groups were comparable by their initial clinical score, bacteriological index (BI), viable bacilli as assessed by the mouse foot pad (MFP), bacillary adenosine triphosphate (ATP) content and also histologically at the time of starting treatment. All these parameters were evaluated every 6 months. The vaccines were well tolerated. All the patients in group I became smear negative by 3.5 years, in group II in 3 years whereas those in group III took 5 years. The incidence of reactions was the same in all the groups during the first 2 years, however, patients of group III (MDT + placebo) continued to have reactions up to 3 years. No viable bacilli could be detected in the local and distal sites as estimated by MFP and bacillary ATP after 12 months in both the immunotherapy groups. These could be detected in patients on MDT alone up to 24 months of therapy. Histologically patients in both the immunotherapy groups (groups I and II) showed accelerated granuloma clearance, histological upgrading and non-specific healing without granuloma formation both at the local and distal sites and this was achieved much earlier compared to the MDT + placebo group. Thus, by the addition of immunotherapy the effective treatment period of achieving bacteriological negativity could be reduced by about 40%, time period of reactions reduced by 33% and there were no reactions and/or relapses in the 10-12 years post-treatment follow-up.