Association of CC-chemokine ligand-2 gene polymorphisms with leprosy reactions

BACKGROUND

C-C motif chemokine ligand 2, a gene that codes for a protein involved in inflammation. Certain SNPs in the CCL2 gene have been studied for their potential associations with susceptibility to various diseases. These SNPs may affect the production and function of the CCL2 protein, which is involved in the recruitment of immune cells to the site of inflammation. Variations in CCL2 may influence the immune response to Mycobacterium leprae infection.

OBJECTIVE

To investigate the association of the C-C motif chemokine ligand-2 single nucleotide polymorphisms with leprosy.

METHODS

CCL2 single nucleotide polymorphisms were analyzed in a total of 975 leprosy patients and 357 healthy controls. Of those, 577 leprosy and 288 healthy controls were analyzed by PCR-RFLP for CCL2 -2518 A>G, 535 leprosy and 290 controls for CCL2 -362 G>C, 295 leprosy and 240 controls for CCL2 -2134 T>G, 325 leprosy and 288 controls for CCL2 -1549 A>T SNPs by melting curve analysis using hybridization probe chemistry and detection by fluorescence resonance energy transfer (FRET) technique in Realtime PCR. The levels of CCL2, IL-12p70, IFN-γ, TNF-α, and TGF-β were estimated in sera samples and correlated with CCL2 genotypes.

RESULTS

The frequency of the GCT (-2518 A>G, -362 G>C, -2134 T>G) haplotype is observed to be higher in leprosy patients compared to healthy controls (P = 0.04). There was no significant difference observed in genotypic frequencies between leprosy patients and healthy controls {(-2518A>G, p = 0.53), (-362 G>C, p = 0.01), (-2134 T>G, p = 0.10)}. G allele at the -2134 site is predominant in leprosy (borderline) without any reaction (8 %) compared to borderline patients with RR reactions (2.1 %) (P = 0.03). GG genotype (p = 0.008) and G allele at -2518 (p = 0.030) of the CCL 2 gene were found to be associated with patients with ENL reaction. An elevated level of serum CCL2 was observed in leprosy patients with the -2518 AA and AG genotypes (p = 0.0001).

CONCLUSIONS

G allele and GG genotype at the CCL2 -2518 site are associated with a risk of ENL reactions.

Mycobacterium tuberculosis Lineages Associated with Mutations and Drug Resistance in Isolates from India

Current knowledge on resistance-conferring determinants in Mycobacterium tuberculosis is biased toward globally dominant lineages 2 and 4. In contrast, lineages 1 and 3 are predominant in India. In this study, we performed whole-genome sequencing of 498 MDR M. tuberculosis isolates from India to determine the prevalence of drug resistance mutations and to understand the genomic diversity. A retrospective collection of 498 M. tuberculosis isolates submitted to the National Institute for Research in Tuberculosis for phenotypic susceptibility testing between 2014 to 2016 were sequenced. Genotypic resistance prediction was performed using known resistance-conferring determinants. Genotypic and phenotypic results for 12 antituberculosis drugs were compared, and sequence data were explored to characterize lineages and their association with drug resistance. Four lineages were identified although lineage 1 predominated (43%). The sensitivity of prediction for isoniazid and rifampicin was 92% and 98%, respectively. We observed lineage-specific variations in the proportion of isolates with resistance-conferring mutations, with drug resistance more common in lineages 2 and 3. Disputed mutations (codons 430, 435, 445, and 452) in the rpoB gene were more common in isolates other than lineage 2. Phylogenetic analysis and pairwise SNP difference revealed high genetic relatedness of lineage 2 isolates. WGS based resistance prediction has huge potential, but knowledge of regional and national diversity is essential to achieve high accuracy for resistance prediction. IMPORTANCE Current knowledge on resistance-conferring determinants in Mycobacterium tuberculosis is biased toward globally dominant lineages 2 and 4. In contrast, lineages 1 and 3 are predominant in India. We performed whole-genome sequencing of 498 MDR M. tuberculosis isolates from India to determine the prevalence of drug resistance mutations and to understand genomic diversity. Four lineages were identified although lineage 1 predominated (43%). The sensitivity of prediction for isoniazid and rifampicin was 92% and 98%, respectively. We observed lineage-specific variations in the proportion of isolates with resistance-conferring mutations, with drug resistance more common in lineages 2 and 3. Disputed mutations (codons 430, 435, 445, and 452) in the rpoB gene were more common in isolates other than lineage 2. Phylogenetic analysis and pairwise SNP difference revealed high genetic relatedness of lineage 2 isolates. WGS based resistance prediction has huge potential, but knowledge of regional and national diversity is essential to achieve high accuracy for resistance prediction.

Predictors of mortality among hospitalized COVID-19 patients and risk score formulation for prioritizing tertiary care-An experience from South India

Background

We retrospectively data-mined the case records of Reverse Transcription Polymerase Chain Reaction (RT-PCR) confirmed COVID-19 patients hospitalized to a tertiary care centre to derive mortality predictors and formulate a risk score, for prioritizing admission.

Methods and findings

Data on clinical manifestations, comorbidities, vital signs, and basic lab investigations collected as part of routine medical management at admission to a COVID-19 tertiary care centre in Chengalpattu, South India between May and November 2020 were retrospectively analysed to ascertain predictors of mortality in the univariate analysis using their relative difference in distribution among ‘survivors’ and ‘non-survivors’. The regression coefficients of those factors remaining significant in the multivariable logistic regression were utilised for risk score formulation and validated in 1000 bootstrap datasets.

Among 746 COVID-19 patients hospitalised [487 “survivors” and 259 “non-survivors” (deaths)], there was a slight male predilection [62.5%, (466/746)], with a higher mortality rate observed among 40–70 years age group [59.1%, (441/746)] and highest among diabetic patients with elevated urea levels [65.4% (68/104)]. The adjusted odds ratios of factors [OR (95% CI)] significant in the multivariable logistic regression were SaO₂<95%; 2.96 (1.71–5.18), Urea ≥50 mg/dl: 4.51 (2.59–7.97), Neutrophil-lymphocytic ratio (NLR) >3; 3.01 (1.61–5.83), Age ≥50 years;2.52 (1.45–4.43), Pulse Rate ≥100/min: 2.02 (1.19–3.47) and coexisting Diabetes Mellitus; 1.73 (1.02–2.95) with hypertension and gender not retaining their significance. The individual risk scores for SaO₂<95–11, Urea ≥50 mg/dl-15, NLR >3–11, Age ≥50 years-9, Pulse Rate ≥100/min-7 and coexisting diabetes mellitus-6, acronymed collectively as ‘OUR-ARDs score’ showed that the sum of scores ≥ 25 predicted mortality with a sensitivity-90%, specificity-64% and AUC of 0.85.

Conclusions

The ‘OUR ARDs’ risk score, derived from easily assessable factors predicting mortality, offered a tangible solution for prioritizing admission to COVID-19 tertiary care centre, that enhanced patient care but without unduly straining the health system.

Active case-finding for tuberculosis in India

Early identification of presumptive tuberculosis (TB) cases through active case-finding (ACF) would be an important complementary strategy to meet the national urgency in accelerating case detection to achieve the goals of 'End TB' strategy. ACF activities have yielded additional cases in different vulnerable groups in India. The yield of cases depends on the screening tool available, the characteristics of the high-risk population being screened, and most importantly, the linkage between effective diagnostic and treatment facilities. The ACF strategy could be both economically and epidemiologically relevant if it could bring down the level of transmission. This needs long-term research focusing on outcomes such as cases averted and reduction in the prevalence of the disease. Available evidence suggests that ACF is likely to be feasible in Indian settings but needs to be scaled up rapidly to create a good impact.

Tuberculous meningitis in children: Clinical management & outcome

Although the occurrence of tuberculous meningitis (TBM) in children is relatively rare, but it is associated with higher rates of mortality and severe morbidity. The peak incidence of TBM occurs in younger children who are less than five years of age, and most children present with late-stage disease. Confirmation of diagnosis is often difficult, and other infectious causes such as bacterial, viral and fungal causes must be ruled out. Bacteriological confirmation of diagnosis is ideal but is often difficult because of its paucibacillary nature as well as decreased sensitivity and specificity of diagnostic tests. Early diagnosis and management of the disease, though difficult, is essential to avoid death or neurologic disability. Hence, a high degree of suspicion and a combined battery of tests including clinical, bacteriological and neuroimaging help in diagnosis of TBM. Children diagnosed with TBM should be managed with antituberculosis therapy (ATT) and steroids. There are studies reporting low concentrations of ATT, especially of rifampicin and ethambutol in cerebrospinal fluid (CSF), and very young children are at higher risk of low ATT drug concentrations. Further studies are needed to identify appropriate regimens with adequate dosing of ATT for the management of paediatric TBM to improve treatment outcomes. This review describes the clinical presentation, investigations, management and outcome of TBM in children and also discusses various studies conducted among children with TBM.

Evaluation of metformin in combination with rifampicin containing antituberculosis therapy in patients with new, smear-positive pulmonary tuberculosis (METRIF): study protocol for a randomised clinical trial

INTRODUCTION

Shorter duration of treatment for the management of drug-susceptible pulmonary tuberculosis (TB) would be a significant improvement in the care of patients suffering from the disease. Besides newer drugs and regimens, other modalities like host-directed therapy are also being suggested to reach this goal. This study's objective is to assess the efficacy and safety of metformin-containing anti-TB treatment (ATT) regimen in comparison to the standard 6-month ATT regimen in the treatment of patients with newly diagnosed sputum smear-positive drug-sensitive pulmonary TB.

METHODS AND ANALYSIS

We are conducting a multicentric, randomised open-label controlled clinical trial to achieve the study objective. The intervention group will receive isoniazid (H), rifampicin (R), ethambutol (E) and pyrazinamide (Z) along with 1000 mg of daily metformin (Met) for the first 2 months while the control group will receive only HRZE. After 2 months, both the groups will receive HRE daily for 4 months. The primary endpoint is time to sputum culture conversion. Secondary endpoints will include time to detection of Mycobacterium tuberculosis in sputum, pharmacokinetics and pharmacogenomics of study drugs, drug-drug interactions, safety and tolerability of the various combinations and measurement of autophagy and immune responses in the study participants.

ETHICS AND DISSEMINATION

The ethics committee of the participating institutes have approved the study. Results from this trial will contribute to evidence towards constructing a shorter, effective and safe regimen for patients with TB. The results will be shared widely with the National Programme managers, policymakers and stakeholders through open access publications, dissemination meetings, conference abstracts and policy briefs. This is expected to provide a new standard of care for drug-sensitive patients with pulmonary TB who will not only reduce the number of clinic visits and lost to follow-up of patients from treatment but also reduce the burden on the healthcare system.

TRIAL REGISTRATION NUMBER

CTRI/2018/01/011176; Pre-results.

Transcription factors STAT-4, STAT-6 and CREB regulate Th1/Th2 response in leprosy patients: effect of M. leprae antigens

Background

Leprosy is an ideal human disease to study T cell regulation as patients show correlation between cytokine skewed Th1-Th2 responses and clinical forms of the disease. The Role of transcription factors on the modulation of Th1 and Th2 responses by M. leprae antigens has not been adequately studied. In the present study, we studied the effect of M. leprae antigens on transcription factors STAT-4, STAT-6 and CREB and their correlation with Th1/Th2 cell mediated immune responses in leprosy.

Methods

Leprosy patients of both categories of tuberculoid leprosy (BT/TT) and lepromatous leprosy (BL/LL) were selected from the OPD of NJ1L & OMD, (ICMR), Agra and healthy individuals (H) were chosen from the staff and students working in the institute. Peripheral blood mononuclear cells (PBMCs) of the study subjects were stimulated with M. leprae antigens (WCL, MLSA, and PGL-1). Sandwich ELISA was done in the culture supernatants of healthy and leprosy patients to detect IL-4, IL-10 and IFN-γ. Further, expression of IFN-γ and IL-4 and activation of STAT4, STAT6 and CREB transcription factors in CD4⁺ T cell with or without stimulation of M. leprae antigens was investigated by flow cytometry.

Results

Lepromatous leprosy patients showed significantly lower IFN-γ and higher IL-4 levels in culture supernatant and significantly low expression of IFN-γ and higher expression of IL-4 by CD4⁺ T cells than healthy individuals with or without antigenic stimulation. Antigenic stimulation significantly increased IL-10 in BL/LL patients but not in BT/TT patients or healthy individuals. PGL-1 stimulation led to significantly higher activation of STAT-6 in BT/TT and BL/LL patients in comparison to healthy individuals. All the three antigens led to activation of CREB in healthy and BT/TT patients but not in BL/LL patients.

Conclusion

Our findings show that M. leprae antigens differentially modulate activation of T cell transcription factors STAT-4/STAT-6 and CREB. These transcription factors are well known to regulate Th1 and Th2 mediated immune response which in turn could play vital role in the clinical manifestations of leprosy. These observations may help to determine how these T cell transcription factors affect the development of immune dysfunction and whether these new pathways have a role in immunomodulation in intracellular diseases like leprosy and TB.

Potential of adjunctive Mycobacterium w (MIP) immunotherapy in reducing the duration of standard chemotherapy against tuberculosis

INTRODUCTION

The need to shorten the treatment duration in tuberculosis has always been felt. Immunotherapy in combination with chemotherapy has been considered a promising approach for this purpose into tuberculosis. We studied the adjuvant immunotherapeutic activity of Mycobacterium indicus pranii (MIP or Mw) in combination with conventional chemotherapy using guinea pig of pulmonary tuberculosis infected with Mycobacterium tuberculosis H37Rv via aerosol.

METHODS

Experimental animals treated with standard chemotherapy and immunotherapy (MIP) separately and in combination of both. Guinea pig lungs evaluated following infection and subsequent therapy at predefine time point. Various cytokine mRNA expressions levels were quantified by quantitative reverse transcriptase PCR at the 4th, 8th and 12th week post-infection of M. tuberculosis.

RESULTS

We determined the time required for bacterial clearance from guinea pig lungs. Standard chemotherapy (RvCh) compared to the animals where chemotherapy plus Mw immunotherpay (RvChMwT) was given. It took 12 weeks to achieve bacterial clearance in the RvCh group while this was achieved in 8 weeks in RvChMwT group. Pro-inflammatory cytokines (IFN-γ, IL-2, IL-12p35 and TNF-α) level were higher in RvCh, RvChMwT and RvMwT group, while the IL-10 and TGF-β were suppressed.

CONCLUSION

Cytokine expression level showed that Mw in conjunction with chemotherapy enhances the effect of pro-inflammatory cytokines (such as, IFN-γ, IL-2, IL-12 and TNF-α) and reduces the production and effect of anti-inflammatory cytokines (like IL-10 and TGF-β) thereby restoring the pro-inflammatory / anti-inflammatory cytokines balance. Thus, the present study indicates that subject to rigorous testing by other parameters, Mw (MIP) as adjunct immunotherapy has potential for reducing treatment duration.

Recurrence of tuberculosis among newly diagnosed sputum positive pulmonary tuberculosis patients treated under the Revised National Tuberculosis Control Programme, India: A multi-centric prospective study

Introduction

There is lack of information on the proportion of new smear—positive pulmonary tuberculosis (PTB) patients treated with a 6-month thrice-weekly regimen under Revised National Tuberculosis Control Programme (RNTCP) who develop recurrent TB after successful treatment outcome.

Objective

To estimate TB recurrence among newly diagnosed PTB patients who have successfully completed treatment and to document endogenous reactivation or re-infection. Risk factors for unfavourable outcomes to treatment and TB recurrence were determined.

Methodology

Adult (aged ≥ 18 yrs) new smear positive PTB patients initiated on treatment under RNTCP were enrolled from sites in Tamil Nadu, Karnataka, Delhi, Maharashtra, Madhya Pradesh and Kerala. Those declared “treatment success” at the end of treatment were followed up with 2 sputum examinations each at 3, 6 and 12 months after treatment completion. MIRU-VNTR genotyping was done to identify endogenous re-activation or exogenous re-infection at TB recurrence. TB recurrence was expressed as rate per 100 person-years (with 95% confidence interval [95%CI]). Regression models were used to identify the risk factors for unfavourable response to treatment and TB recurrence.

Results

Of the1577 new smear positive PTB patients enrolled, 1565 were analysed. The overall cure rate was 77% (1207/1565) and treatment success was 77% (1210 /1565). The cure rate varied from 65% to 86%. There were 158 of 1210 patients who had TB recurrence after treatment success. The pooled TB recurrence estimate was 10.9% [95%CI: 0.2–21.6] and TB recurrence rate per 100 person–years was 12.7 [95% CI: 0.4–25]. TB recurrence per 100 person–years varied from 5.4 to 30.5. Endogenous reactivation was observed in 56 (93%) of 60 patients for whom genotyping was done. Male gender was associated with TB recurrence.

Conclusion

A substantial proportion of new smear positive PTB patients successfully treated with 6 –month thrice-weekly regimen have TB recurrence under program settings.

Genital tuberculosis in females

The morbidity and mortality due to tuberculosis (TB) is high worldwide, and the burden of disease among women is significant, especially in developing countries. Mycobacterium tuberculosis bacilli reach the genital tract primarily by haematogenous spread and dissemination from foci outside the genitalia with lungs as the common primary focus. Genital TB in females is a chronic disease with low-grade symptoms. The fallopian tubes are affected in almost all cases of genital TB, and along with endometrial involvement, it causes infertility in patients. Many women present with atypical symptoms which mimic other gynaecological conditions. A combination of investigations is needed to establish the diagnosis of female genital TB (FGTB). Multidrug anti-TB treatment is the mainstay of management and surgery may be required in advanced cases. Conception rates are low among infertile women with genital TB even after multidrug therapy for TB, and the risk of complications such as ectopic pregnancy and miscarriage is high. More research is needed on the changing trends in the prevalence and on the appropriate methods for diagnosis of FGTB.

Expression profile of CXCL12 chemokine during M. tuberculosis infection with different therapeutic interventions in guinea pig

Mycobacterium indicus pranii (MIP) already established as an immune-modulator in mycobacterial infections generates immune response by acting on CXC chemokines. In the present study, the immunomodulatory effect of MIP in conjunction with chemotherapy against M.tb infection was evaluated by colony forming units (CFUs) following aerosol infection to guinea pig and by measuring CXCL12 chemokine expression using q-PCR and in situ RT-PCR. Different experimental groups included, infection (Rv), immunoprophylaxis (RvMw), chemotherapy (RvCh) and combination of immunoprophylaxis+chemotherapy (RvChMw) group and normal healthy (NH) group. In the combination of immunoprophylaxis+chemotherapy (RvChMw) group, the CFU counts reduced significantly (p<0.001) at 4th week of infection as compared to other treated groups (RvMw and RvCh group). The expression of CXCL12 was recorded in all the treated groups of animals. The study demonstrated suppressed expression of CXCL 12 in both immunoprophylaxis as well as chemotherapy groups (6th and 8th week) that become elevated in immunoprophylaxis plus chemotherapy group (10th week), at which time point no CFUs were detected in RvCh and RvChMw group. The findings indicate that the expression of CXCL12 is associated with good response to anti - tubercular treatment. Thus, prior immunization with MIP appears to show good immunomodulatory effect to release CXCL12 chemokine during infection and also correlates with enhanced effect to chemotherapy.

Predictors of unfavourable treatment outcome in patients with multidrug-resistant tuberculosis in India

Setting: India has one of the highest global rates of multidrug-resistant tuberculosis (MDR-TB), which is associated with poor treatment outcomes. A better understanding of the risk factors for unfavourable outcomes is needed. Objectives: To describe 1) the demographic and clinical characteristics of MDR-TB patients registered in three states of India during 2009-2011, 2) treatment outcomes, and 3) factors associated with unfavourable outcomes. Design: A retrospective cohort study involving a record review of registered MDR-TB patients. Results: Of 788 patients, 68% were male, 70% were aged 15-44 years, 90% had failed previous anti-tuberculosis treatment or were retreatment smear-positive, 60% had a body mass index < 18.5 kg/m² and 72% had additional resistance to streptomycin and/or ethambutol. The median time from sputum collection to the start of MDR-TB treatment was 128 days (IQR 103-173). Unfavourable outcomes occurred in 40% of the patients, mostly from death or loss to follow-up. Factors significantly associated with unfavourable outcomes included male sex, age ⩾ 45 years, being underweight and infection with the human immunodeficiency virus. Adverse drug reactions were reported in 24% of patients, with gastrointestinal disturbance, psychiatric morbidity and ototoxicity the most common. Conclusion: Long delays from sputum collection to treatment initiation using conventional methods, along with poor treatment outcomes, suggest the need to scale up rapid diagnostic tests and shorter regimens for MDR-TB.

Role of LTA4H Polymorphism in Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome Occurrence and Clinical Severity in Patients Infected with HIV

Background

Paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an inflammatory phenomenon complicating HIV management in coincidental tuberculosis (TB) infection, upon immune reconstitution driven by antiretroviral therapy (ART). Leukotriene A4 hydroxylase (LTA4H), an enzyme which converts LTA₄ to LTB₄, regulates the balance between the anti-inflammatory lipoxins and pro-inflammatory LTB₄, with direct implications in TB-driven inflammation. In humans, a single nucleotide polymorphism (SNP) in the LTA4H promoter which regulates its transcriptional activity (rs17525495) has been identified and described to impact clinical severity of TB presentation and response to corticosteroid therapy. Notably, the role of LTA4H on TB-IRIS has not been previously evaluated. Here, we performed an exploratory investigation testing the association of LTA4H polymorphism with respect to frequency of TB-IRIS occurrence and severity of TB-IRIS presentation in HIV-TB co-infected individuals.

Methods

Genotypic evaluation of the LTA4H enzyme from available samples was retrospectively correlated with clinical data captured in case sheets including IRIS details. The cohort included patients recruited from a prospective cohort study nested within a randomized clinical trial (NCT0933790) of ART-naïve HIV+ patients with newly diagnosed rifampicin sensitive pulmonary TB in South India. Frequency of the wild type genotype (CC), as well as of the mutant genotypes (CT or TT) in the IRIS and non-IRIS patients was estimated. Comparative analyses were performed between wild genotype (CC) and the mutant genotypes (CT or TT) and tested for association between the LTA4H polymorphisms and IRIS incidence and clinical severity.

Results

A total of 142 eligible ART-naïve patients were included in the analyses. Eighty-six individuals exhibited the wild genotype (CC) while 56 had mutant genotypes (43-CT and only 13-TT). Variant allele frequency was 0.23 and 0.26 in non-IRIS group and in IRIS group, respectively. Upon ART initiation, 51 patients developed IRIS while 91 did not. IRIS incidence was 34% and 37% in the wild (CC) and mutant type (CT/TT), respectively (p = 0.858) with a higher frequency of severe IRIS presentation in the mutant genotype group compared to the wild type genotype (p = 0.0006). A logistic regression model confirmed the association between the presence of CT/TT genotypes and occurrence of severe IRIS. Corticosteroid therapy successfully resolved IRIS in all cases irrespective of the LTA4H genotype.

Conclusion

A higher incidence of severe IRIS among patients with mutant LTA4H genotypes (CT and TT) was observed compared to the wild type, despite similar IRIS incidence and immune restoration in both groups. Steroids were effective in alleviating IRIS in all the genotypes.

Association of viable Mycobacterium leprae with Type 1 reaction in leprosy

The working hypothesis is that, viable Mycobacterium leprae (M. leprae) play a crucial role in the precipitation of Type 1 reaction (T1R) in leprosy.

MATERIAL AND METHODS

A total of 165 new multibacillary patients were studied. To demonstrate presence of viable M. leprae in reactional lesion (T1R+), three tests were used concurrently viz. growth in the mouse foot pad (MFP), immunohistochemical detection of M. leprae secretory protein Ag85, and 16s rRNA--using in situ RT-PCR. Mirror biopsies and non reactional lesions served as controls (T1R-).

FINDINGS

A significantly higher proportion of lesion biopsy homogenates obtained at onset, from T1R(+) cases have shown unequivocal growth in MFP, proving the presence of viable bacteria, as compared to T1R(-) (P < 0.005). In contrast, few Mirror biopsies were positive in both T1R(+) and T1R(-). With respect to Ag85, while the overall positivity was higher in T1R(+) (74%), however the intensity of staining (Grade 2+) was disproportionately higher in T1R(+) BT-BB lesions 11/20 (55%). In the rebiopsies obtained during a repeat episode of T1R, Ag 85 as well as 16s rRNA, positivity (62% & 100%) was higher in T1R(+). It is inferred therefore 'viable' bacteria are an essential component in T1R and difference in the quality of bacilli, not the quantity or the ratio of dead to viable play a role in the precipitation of T1R. In conclusion, the findings show that 'metabolically active' M. leprae is a component/prerequisite and the secretory protein Ag 85, might be the trigger for precipitation of T1R.

High resolution structural changes of Schwann cell and endothelial cells in peripheral nerves across leprosy spectrum

A systematic ultrastructure of peripheral nerves across the spectrum of leprosy was studied with an aim to better understanding the pathogenesis of nerve involvement in leprosy using light and electron microscope. The pathogenesis of nerve destruction varies in leprosy considerably along the spectrum. The study has begun to shed new light on some aspects of the infection of Mycobacterium leprae (M. lepare) and phenomenon has opened new avenue of research and possible mechanism of pathogenesis in TT/BT/BL/LL leprosy. In tuberculoid type (TT) and borderline tuberculoid (BT) leprosy, the degenerative changes of Schwann cells (SCs) and presence of perineural and perivascular cuffing by mononuclear cells. The endoneurial blood vessel (EBV) showed thickening of basement membrane with hypertrophy of EC leading to narrowing or complete occlusion of lumen and causing ischemia. However, borderline lepromatous (BL) and lepromatous leprosy (LL) foamy macrophages and vacuolated SC contain numerous small dense materials, irregular in shape and size was prominent and, considered to be degenerated and fragmented M. Leprae. The dense materials were also found in the cytoplasm of vascular EC. It was revealed that besides SC, the EC of EBV frequently harbor M. leprae in LL. The lumen of the EBV was wide open with enlarged nucleus. In the present study, the ultrastructural characteristics suggest that hypersensitivity mechanisms are possibly responsible for nerve damage in TT/BT leprosy. However, the study indicates that the mechanisms of nerve damage in BL/LL are basically different wherein hypersensitivity appears to play a very limited role.

Evaluation of the diagnostic value of immunocytochemistry and in situ hybridization in the pediatric leprosy

Leprosy is characterized by a long and variable incubation period and a chronic clinical course. Diagnosis of leprosy is essentially based on clinical features. Although the majority of cases can be diagnosed clinically yet alternative methods for diagnosis are required especially for early cases. Immunocytochemistry and in situ hybridization can be a valuable tool for diagnosis for early cases. The present study is aimed to assess the diagnostic value of immunocytochemistry and in situ hybridization in cytological specimens and to compare these techniques with Z.N. staining. This prospective study was carried out in 26 patients below 18 years of age of leprosy. Clinical examination of each patient was done and categorized according to IAL. After taking consent, three skin smears was taken, one for Z.N. staining and remaining two for immunocytochemistry and in situ hybridization respectively. Routine skin smear examination by Z.N. staining method confirmed the diagnosis in 4/26 (15.83%) and these belonged to BB, BL category. Immunocytochemistry showed positivity in 10/15 (66.6%) in BT and 72.7% in BB/BL leprosy. Immunocytochemistry improved the diagnosis by 53.85%, and the results were statistically significant (p < 0.01). In situ hybridization showed the positive results in 80% cases of BT leprosy and 90.9% cases of BB/BL leprosy. In situ hybridization improved the diagnosis by 70% in comparison to ZN staining and the results were statistically significant (p < 0.01). This study supports that immunocytochemistry and in situ hybridization enhance the diagnosis of leprosy when compared to routine skin smears stained by Z.N staining. They are important diagnostictoolsfor definitive diagnosis in early as well as established cases of leprosy.

Clinical and histopathological evaluation of the effect of addition of immunotherapy with Mw vaccine to standard chemotherapy in borderline leprosy

This study reports detailed analysis of clinical parameters and clearance of granuloma in borderline leprosy patients treated with immunotherapy and chemotherapy. It aims to assess the additive effect of immunotherapy (Mwvaccine) with standard MDT on clinical status of untreated borderline leprosy cases and on granuloma fraction of untreated borderline leprosy cases. Patients attending the OPD were serially recruited in two groups. A total of 150 cases in one treatment (trial) group (Mw vaccine plus MDT) and 120 cases in another treatment (control) group (MDT only) of border line leprosy have been included. After the formal written consent, detailed clinical examination, charting, smear examination of all untreated borderline patients of both groups was done, biopsies were taken from the active lesions of all patients of both groups at start of therapy and every six month thereafter till the completion of therapy. The same procedure was repeated every six months during the follow-up period. Standard MDT was given to all the patients of both groups according to type of disease. Mw vaccine 0.1 ml (0.5 x 10(9) bacilli) was injected intra-dermally at the start of therapy and every six months in addition to chemotherapy to the treatment group. The BT cases were followed up after 6 doses of MDT and 2 doses of Mw vaccine, and, the BB, BL cases were followed up after 24 doses of MDT plus 5 doses of Mw vaccine. Clinically, greater and faster improvement was observed in all the clinical parameters, faster attainment of smear negativity and two episodes of lepra reaction occurred in cases treated with combined chemotherapy and immunotherapy, as compared to controls (chemotherapy alone) wherein clinical improvement was slower in all parameters, slower attainment of smear negativity in bacillary index and seven showed the occurrence of reactions, histipathologically in addition to more rapid clearance of granuloma in immunotherapy treated group, a significant finding was an increase in the epithelioid cells population in this group. This suggests a possible immunoactivation of the macrophages especially in BB/BL immunotherapy group. Overall comparison of regression induced by chemotherapy alone with that induced by combined chemotherapy and immunotherapy shows a greater reduction in clinical parameters as well as granuloma fraction in BT cases as well as in BB/BL cases. This trial shows the potential usefulness of this approach of addition of immunotherapy to standard chemotherapy in borderline leprosy cases which leads to in faster recovery from disease reduced chances of reactions and faster granuloma clearance. Such information is expected to be useful in improving the immunotherapeutic approaches for treatinggranulomatous conditions in general and in leprosy in particular.

Histological diagnosis of early and suspicious leprosy by in situ PCR

Leprosy is a chronic mycobacterial disease whose diagnosis is primarily based on clinico-pathological examination and supported by slit skin smears for the presence of acid fast bacilli (AFB). However, definitive diagnosis of early leprosy and those suspected to have the disease but not histologically confirmed pose major public health problems. The present study reports the utility of the in situ Polymerase Chain Reaction amplification (PCR) directed at a 530bp fragment of DNA encoding the 36kd antigen of the causative Mycobacterium leprae for the diagnosis of such patients using skin biopsies of lesions. Twenty five adult patients (aged 15-50yrs) each from the clinical categories of Early and clinically Suspect leprosy were selected for the study after obtaining permission. They had solitary lesions, which were negative for AFB on slit skin smear examination. Routine histopathology confirmed the diagnosis of leprosy in 8/25 (32%) cases in the category of Early leprosy with AFB being seen in 2 biopsies, and in 5/25(20%) cases of Suspect leprosy with AFB being seen in a solitary case. The Direct in situ PCR procedure which was performed in the histologically unconfirmed cases improved the diagnosis with positive results observed in 12/17 (70.6%) cases of Early (p=0.001) and in 12/20 (60%) cases of Suspect Leprosy (p=0.005 indicating the usefulness of the Direct in situ PCR to establish the diagnosis of leprosy in histologically doubtful cases.

Mycobacterium indicus pranii as stand-alone or adjunct immunotherapeutic in treatment of experimental animal tuberculosis

BACKGROUND & OBJECTIVES

Mycobacterium w (M.w) is a saprophytic cultivable mycobacterium and shares several antigens with M. tuberculosis. It has shown good immunomodulation in leprosy patients. Hence in the present study, the efficacy of M.w immunotherapy, alone or in combination with multi drug chemotherapeutic regimens was investigated against drug sensitive M. tuberculosis H37Rv and three clinical isolates with variable degree of drug resistance in mice.

METHODS

BALB/c mice were infected with M. tuberculosis H37Rv (susceptible to all first and second line drugs) and three clinical isolates taken from the epository of the Institute. The dose of 200 bacilli was used for infection via respiratory route in an aerosol chamber. Chemotherapy (5 days/wk) was given one month after infection and the vaccinated group was given a dose of 1x107 bacilli by subcutaneous route. Bacterial load was measured at 4 and 6 wk after initiation of chemotherapy.

RESULTS

M.w when given along with chemotherapy (4 and 6 wk) led to a greater reduction in the bacterial load in lungs and other organs of TB infected animals compared to. However, the reduction was significantly (P<0.05) more in terms of colony forming units (cfu) in both organs (lungs and spleen).

CONCLUSION

M.w (as immunomodulator) has beneficial therapeutic effect as an adjunct to chemotherapy.

Evaluation of diagnostic role of in situ PCR on slit-skin smears in pediatric leprosy

A large proportion of early cases of leprosy in children remain AFB negative in skin smears. Such cases required additional techniques to confirm the diagnosis. In situ PCR on slit- skin smears is minimally invasive and less cumbersome as compared to skin biopsies. This study was initiated in our institute with the objective to evaluate the diagnostic value of in situ PCR on slit- skin smears in pediatric leprosy. A total of 25 cases of leprosy below 16 years of age were included in the study. After detailed history and thorough clinical examination, informed consent was obtained from the parents of children for slit- skin smears from lesion sites for AFB staining and for in situ PCR technique. Cases were clinically categorized according to IAL classification into indeterminate (I), tuberculoid tuberculoid (TT), borderline tuberculoid (BT), borderline borderline (BB), borderline lepromatous (BL) and lepromatous (LL). Most of the patients (76%) were between 9-16 years of age and 64% of the cases had history of contact with leprosy patients within the family. Skin smears were positive for AFB in only 20% of the cases. On applying in situ PCR, it was observed that 62.5% cases of I/TT/BT/BB category and 88.8% of BL/LL category gave positive signals. Overall in situ PCR confirmed the diagnosis in 72% cases while by slit smears diagnosis was confirmed in only 20% of cases. Further, out of 20 skin smear negative cases, 13 were positive by in situ PCR. Specificity of the signals of in situ PCR was established by demonstrating the absence of signals in nonleprosy dermatological conditions of vitiligo and P.alba. This study supports the potential usefulness of in situ PCR on slit- skin smears of early pediatric leprosy cases. This strategy will be especially useful in cases where skin smears are negative and in those cases where skin biopsy can not be done either because of unusual locations of lesions or because of sensitive age of the patients.

Comparative growth pattern of multi drug resistance versus susceptible isolates of Mycobacterium tuberculosis in mice lungs

BACKGROUND & OBJECTIVE

Rise in prevalence of multi-drug resistance (MDR) in tubercle bacilli is a serious cause of concern. As mutations with two house keeping genes rpoB and katG are associated with resistance to two important anti-tubercular drugs rifampicin and isoniazid respectively, there is a need to understand the growth kinetics of organisms with such mutated genes in experimental animals. This study was undertaken to study the growth kinetics of susceptible as well multi-drug resistance Mycobacterium tuberculosis isolates in mice.

METHODS

Two MDR (having mutations in rpoB and catG) and two drug susceptible isolates of M. tuberculosis along with H37Rv were grown in mice after aerogenic infection.

RESULTS

The MDR isolates grew slowly up to 3 wk though the growth was significantly different from sensitive strains. However, after 3 wk, the growth in sensitive as well MDR strains was similar, suggesting that even the mutations in the MDR strains did not have any impact on the growth kinetics.

INTERPRETATION & CONCLUSION

The effect of mutations in other parts of these genes need to be studied. Retention of property of MDR strains to establish infection after aerogenic infection has epidemiological significance in terms of the transmission of MDR tuberculosis.

Two microbiological relapses in a patient with lepromatous leprosy

A lepromatous patient treated with dapsone in the pre-MDT era to the point of smear negativity (> 6 years), relapsed 5 years after stopping treatment. He was then put on WHO-MDT for multibacillary (MB) leprosy, and was treated again; he had negative slit skin smears (3 years). He again presented with a relapse of leprosy 17 years after stopping treatment, and this time he presented with borderline leprosy in reaction.

Changing profile of disease in leprosy patients diagnosed in a tertiary care centre during years 1995-2000

A hospital based retrospective study was carried out to determine change in the profile of disease in leprosy patients taking 1995 as baseline and compared with the profile seen in year 2000. A total of 2149 and 1703 cases were studied respectively of year 1995 and 2000. Male to female ratio slightly increased from 2.95:1 in year 1995 to 3.4:1 in year 2000. Majority of patients were of borderline type in both years. Proportion of cases with MB leprosy was nearly same in females (60.8%) and males (63.1%) in year 1995 and in year 2000 (64.8% females and 67.6% males). Proportion of highly bacillary cases has decreased over the years in females (from 20.95% in 1995 to 11.7% in year 2000, p=0.03) as well as in males (from 25% in 1995 to 15.5% in year 2000, p=0.001). Incidence of total reactions increased from 27.6% to 35.4% over the years which is significant (p<0.01). Proportion of type 1 reactions were more in reproductive age group in females in both years (p<0.05) and of type 2 reactions were significantly (p > or = 0.05) more in males in both years. Incidence of disability (both grade 1 and grade 2) was significantly more in males than in females in both years (p > or = 0.04). Grade 1 disability has significantly increased over years in females from 10.11% to 14.8%(p<0.03) as well as in males from 13.27% to 21.3%(p<0.001). Onset of reactions was associated with pregnancy/lactation in 62% of cases and with menopause in 21% of cases in 2000, which suggests strong correlation with hormonal imbalance. To conclude while leprosy incidence has declined after MDT, recognition and management of reactions in women around changes in their hormonal levels should be properly monitored for early and effective management.

PCR and in-situ hybridization for diagnosis of leprosy

OBJECTIVE

To assess the diagnostic value of Polymerase Chain Reaction (PCR) and in situ hybridization.

METHODS

This prospective study was carried out in 22 patients

RESULTS

The histopathological examination confirmed the clinical diagnosis in 27.2% cases only. In situ hybridization showed a positivity of 42.8% in early (I/BT) and 46.7% in BB/BL group. In situ hybridization thus enhanced the diagnosis by 18.1%. PCR targeting 36 kDa gene of M. leprae was performed on 15 cases. In these 15 cases, histopathology confirmed the diagnosis in 4 cases (26.6%) and PCR confirmed the diagnosis in 10 cases (66.6%), thus enhancing the diagnosis by 40%.

CONCLUSION

36 kDa PCR and in situ hybridization enhance the diagnosis of leprosy when compared to routine histopathology. They are important diagnostic tools for definitive diagnosis in early and doubtful cases of leprosy.

Diagnostic value of in situ Polymerase Chain Reaction in leprosy

OBJECTIVE

This prospective study was carried out to assess the diagnostic value of in situ Polymerase Chain Reaction in leprosy, particularly in enhancing the histopathological diagnosis.

METHOD

Clinical examination of 20 patients (< 16 yr) was done and skin smear for AFB was prepared. Biopsy of lesion site was taken for histopathological examination and in situ PCR testing.

RESULTS

The histopathological examination confirmed the clinical diagnosis in 45% cases only; non-specific histopathology was reported in the remaining 55% cases. In situ PCR showed a positivity of 57.1% in early/localized form of leprosy (IIBT) and 61.5% in (BB/BL) group. When compared to histopathology examination, a significant enhancement of 15% in diagnosis was seen. With in situ PCR, the diagnosis could be confirmed in 4/11 (36.3%) cases with non-specific histopathological features, (which is common in early disease) in addition to confirmation of 8/9 (88.8%) histopathologically-confirmed tissue sections. Histopathology and in situ PCR, combined together, confirmed the diagnosis in 13/20 cases (65% of total cases).

CONCLUSION

Thus, in situ PCR is an important diagnostic tool especially in early and doubtful cases of leprosy.

Persister studies in leprosy patients after multi-drug treatment

Cutaneous biopsies were collected from leprosy patients who attended the out-patient department of the Institute for treatment at different intervals, i.e., 12 months, 18 months, 24 months, 36 months, and more after beginning the multi-drug treatment therapy (M.D.T.). The patients belonged to the two drug regimens; (i) standard multibacillary (MB) M.D.T. after 12, 24, and 36 months; or (ii) standard M.D.T. + Minocycline 100 mg once a month (supervised) + Ofloxacin 400 mg once a month supervised for 12 months Biopsies were processed for mouse footpad inoculation and for estimating ATP levels by bioluminescence assay as per established methods. Viable bacilli were observed in 23.5% up to 1 year, 7.1% at 2 years, and in 3.84% at 3 years of M.D.T. by MFP and 29.4%, 10.7%, and 3.84% by ATP assay in the M.D.T. group at the same time period, respectively, but not in M.D.T. + Minocycline + Ofloxacin group after one year. The overall percentage of persisters was 5.55% by MFP and 7.14% by ATP assay up to 3 years of treatment.

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.

In situ Hybridization in the Histological Diagnosis of Early and Clinically Suspect Leprosy

The present study tests the utility of the in situ hybridization procedure for M. leprae rRNA in the histological diagnosis of early leprosy and clinically suspect leprosy, both diagnostically demanding situations. The histological confirmation obtained with routine histopathology (Haematoxylin-Eosin staining for studying morphologic alterations and Fite-Faraco staining for demonstration of acid-fast bacilli) were 32% for early leprosy and 25% for clinically suspect leprosy. With performance of the in situ hybridization on the histologically unconfirmed cases, the positivity rates obtained were 58.8% and 55%, respectively. The results of the study confirm the utility of the procedure in the diagnostically difficult situations of early and suspect leprosy, and it is proposed that the procedure be employed in situations of clinical doubt.

Patients presenting with defined areas of sensory loss--a preliminary study

Thirty patients presenting with circumscribed areas of clearly demonstrable hypoesthesia were chosen from amongst those attending this Institute. Their history and clinical features were recorded, lepromin test was done for reading at four weeks, and peripheral part of the hypoesthetic area was biopsied for histopathology and immunostaining. The subjects were predominantly adult males with the symptomatic sites limited to the extremities. On routine histopathological examination of the symptomatic sites, the diagnosis of leprosy, using defined criteria, could be made in six cases (20%). Immunostaining of the remaining sections showing either no pathology or a nonspecific pathology revealed the presence of mycobacterial antigen in five of the 24 cases (20.83%). Overall, leprosy could be diagnosed in 11 of the 30 cases studied (36.66%). This study shows that leprosy may be an important cause of circumscribed areas of sensory deficit.

Effect of treatment on PCR positivity in multibacillary leprosy patients treated with conventional and newer drugs ofloxacin and minocycline

In order to develop objective criteria to monitor trends of therapeutic responses positivity of PCR signals and ATP assay methods has been compared in multibacillary (MB) leprosy patients. Biopsies from lesions of 95 BL/LL patients before and after one year of treatment with a new drug regimen comprising of conventional and newer drugs ofloxacin and minocycline have been studied. These biopsies were processed for bacillary ATP assay and PCR positivity for a 36 kDa gene target by earlier published methods. In the untreated patients bacillary ATP levels were detectable in all specimens and ranged from 0.02 to more than 36 pg/millions organisms. After one year of treatment ATP levels were not detectable in any of the 57 biopsies specimens available for analysis. However, PCR signals were detectable in 3 out of 57 biopsies. In two specimens signals were very weak detectable only by hybridization. It may be concluded that DNA based PCR assay may be useful in monitoring the trends of therapeutic responses in MB patients under treatment.

Assessment of viability by normal mouse foot-pad and bacillary ATP bioluminescence assay in multibacillary cases treated with an MDT regimen using conventional as well as newer drugs like minocycline and ofloxacin

The therapeutic effect of a drug regimen of conventional drugs as well as newer drugs like ofloxacin and minocycline in smear-positive multibacillary (MB) leprosy cases was assessed by mouse foot-pad and ATP bioluminiscence methods. Biopsies were taken before starting treatment and after one year of treatment. They were processed for viability assessment by normal mouse foot-pad inoculation and bacillary ATP assay techniques. The test regimen was quite effective in its anti-bacterial effect as it was found to result in loss of bacillary viability in all the cases, as assessed by both methods.

Chemotherapy trials in MB leprosy using conventional and newer drugs pefloxacin and minocycline

One hundred, untreated, smear positive BB, BL and LL patients were treated with a regimen comprising of once a month, supervised, 600 mg of Rifampicin+ 400 mg Ofloxacin + 100 mg of Minocycline in addition to self administered 100 mg dapsone and 50 mg of clofazimine daily for twelve months.The treatment was then stopped and patients were followed up on placebo. This study reports the preliminary results after 2.5 to 3.5 years of post treatment follow-up. The drugs were well tolerated, the clinical response to the treatment was very good, and there was no case of treatment failure. Bacteriologically 25 out of the total 70 patients available for follow- up were still positive at the end of one year of treatment. These patients continued to progress satisfactorily and four patients were still positive at the end of 2 years. No growth was observed in the normal mouse foot pad after one year of therapy. No bacillary ATP was detected in the biopsy tissues after one year. While no M. leprae specific rRNA was detectable in any of the specimens after one year of treatment, weak PCR signals were detectable in 3/57 specimens at that period. In the follow up available no patient has relapsed. The patients are being followed up on placebo and longer follow-up is required to draw firm conclusions.

Histology and immuno-histology of lesions clinically suspicious of leprosy

Forty-six patients presenting with lesions clinically suspicious of leprosy were selected among patients attending the outpatient department (OPD) of our Institute. The lesions were biopsied deeply for histological analysis. The cases chosen commonly belonged to the 20-35 years age group, were predominantly males, with rare cases of leprosy within the family (2/46, 4.35%). The clinical presentation in most of the cases was that of a solitary lesion, (44/46, 95.65%) located in one of the extremities (40/46, 86.95%). A positive Mitsuda reaction could be elicited in 40% of the cases. Routine histopathologic analysis using defined criteriae, has established the diagnosis of leprosy in 16/46 (34.78%) cases with positivity for acid-fast bacilli in 4 cases. The remaining cases (25/46, 54.35%) exhibited a non-specific histopathology with a perivascular/periadnexal mononuclear cell infiltrate, few (5/46, 10.86%) exhibited minimal or no histopathological features. The sections with nonspecific or minimal pathology when immunostained for the presence of mycobacterial antigen exhibited positivity in 11/30 (36.6%) cases. Presuming the features observed to be consequent to the presence of antigens nearby, the diagnosis of leprosy was significantly enhanced compared to the diagnosis achieved with routine histopathology alone.

Detection of viable organisms in leprosy patients treated with multidrug therapy

Cutaneous biopsies were collected from multibacillary leprosy patients who attended the out-patient department of Jalma Institute for treatment at different time intervals, i.e. 6 months, 12 months, 18 months, 24 months, 30 months, 36 months and 42 months after starting multidrug therapy (MDT) when they were still skin smear positive. Biopsies were processed for inoculation into mouse foot pad (MFP) and estimation of bacillary ATP levels by bioluminescent assay (ATP assay) by earlier established procedures. Viable bacilli were detectable after 1 year (25% cases by MFP and 31% cases by ATP assay), 2 years (8% cases by MFP and 12% cases by ATP assay) and 3 years (4% cases by both MFP and ATP assays). Overall, the percentage of the persisters was 10% by MFP and 13% by ATP assay. It would be important to carry out surveillance studies in larger number of BL/LL cases to know the trends and also the resultant relapses.

Microdensitometric scanning procedure for quantitative assessment of hybridization of rRNA targeting probes in leprosy

In order to develop an objective criteria of grading of positivity of hybridization signals of gene probes targeting rRNA, a microdensitometric scanning procedure was standardised. Ribosomal RNA was extracted from the bacilli harvested from biopsies of leprosy cases across the spectrum and blotted on nitro-cellulose membranes. M. leprae specific rRNA targeting oligonucleotide probes were end-labelled and hybridization was done by the technique standardised and published earlier. The autoradiographs were developed and microdensitometric scanning was done by altering different parameters. Positivity was graded in 5 grades and compared with visual positivity. Microdensitometric scanning procedure and 5 grade system appear to be useful and reproducible. Signals in paucibacillary specimens were in 2+ to 3+ grading range whereas those in multibacillary specimens varied in grades from 2+ to 5+. This approach appears to have potential usefulness for assessing the bacillary load (possibly viable) in the clinical specimens from leprosy cases.

Detection of M. leprae by gene amplification; combined ethidium-bromide staining and probe hybridization

Biopsy and skin-scraping specimens from 130 leprosy cases across the disease spectrum (56 TT/BT/I, 73 BB/BL/LL, and 1 neuritic case) and 50 healthy contacts were studied to assess the application of gene amplification. The nucleic acids from these clinical specimens were extracted by an integrated freeze-thawing--optimized lysozyme-/proteinase-k treatment-purification and fractionation procedure. The nucleic acids from cultured organisms were isolated by the stepwise procedure earlier standardized at this laboratory. Gene amplification for a 360-bp fragment of the 18-kDa protein gene was carried out using primer and the procedure described by its developers, and a 360-bp fragment on Southern blot was taken as the yardstick of positivity. The polymerase chain reaction product was analyzed by electrophoresis, ethidium-bromide (EB) staining, and blot (B) hybridization. Overall sensitivity ranged from 71% in specimens with undetectable acid-fast organisms to 100% in specimens with demonstrable acid-fast bacilli. A positivity of 73% in TT/BT/I specimens and 93% in BB/BL/LL specimens was observed. Four combinations were discerned: EB+, B+ (71%); EB-suspicious, B+ (14%); EB-, B+ (3%) and EB-, B- (12%). By combining the blot hybridization with EB staining, the sensitivity could be significantly improved as compared to EB staining alone. The test was found to be absolutely specific by the absence of any false positivity in control specimens as well as with purified DNAs from mycobacterial as well as non-mycobacterial organisms, grown from these specimens. It is recommended that for optimum sensitivity and specificity both EB staining and blot hybridization should be done.

Understanding anatomical terms

Words are our masters and words are our slaves, all depending on how we use them. The whole of medical science owes its origin to Greco-Roman culture and is replete with terms whose high sound is not necessarily accompanied by sound meaning. This is even more the case in the initial, pre-clinical years. Anatomical terminology seems bewildering to the initiate; and maybe that is a reason why love of anatomy as a subject does not always spill over through later years. Employing certain classifications of the origin of the anatomical terms, we have prepared an anthology that we hope will ease the student's task and also heighten the student's appreciation of the new terms. This centers on revealing the Kiplingian "how, why, when, where, what, and who" of a given term. This presentation should empower students to independently formulate a wide network of correlations once they understand a particular term. The article thus hopes to stimulate students' analytic and synthetic faculties as well. A small effort can reap large rewards in terms of enjoyment of the study of anatomy and the related subjects of histology, embryology, and genetics. It is helpful to teachers and students alike. This exercise in semantics and etymology does not demand of the student or his teacher any background in linguistics, grammar, Greek, Latin, Sanskrit, anatomy, or medicine.

Treatment of bacilliferous BL/LL cases with combined chemotherapy and immunotherapy

Thirty-six, untreated borderline lepromatous/lepromatous (BL/LL) leprosy patients with an initial bacterial index (BI) of 4+ to 6+ were serially allocated to three treatment groups. Group I patients received a slightly modified WHO regimen (rifampin once a month, clofazimine and dapsone daily) and BCG intradermally (i.d.) (0.1 mg/per dose). Group II patients were administered the same MDT and Mycobacterium w (2 x 10(8)) killed bacilli/dose i.d., and Group III received the same MDT with 0.1 ml of distilled water i.d. Vaccination was repeated every 6 months. Biopsies were taken from the local site of vaccination and from a distant site, i.e., the back. The progress was monitored periodically by clinical, histopathological and bacterial (BI, mouse foot pad, ATP) parameters. Twenty-five patients had completed a follow up of more than 2 years. These included: 7 in Group I, 10 in Group II, and 8 in Group III. One patient of the MDT + BCG group who was progressing well dropped out after 28 months. In cases on combined chemotherapy and immunotherapy, no viable bacilli were demonstrable by mouse foot pad and ATP measurement after 6 months (at 12 months or afterward). However, in come of the control cases on MDT alone, viable bacilli could be detected even up to 18 months (by mouse foot pad) and 2 years (by ATP estimation). With 36 months of treatment, the mean BI decreased from 4.64+ to 1.66+ in the group on MDT alone (controls), 4.9+ to 0.08+ in the MDT + BCG group, and 4.75+ to 0 in the MDT+Mycobacterium w group. Compared with the MDT and MDT + BCG groups, the fall in the BI was significantly more in the MDT + Mycobacterium w group at 12, 18, and 24 months. While all of the cases in the Mycobacterium w groups became smear negative by 36 months, it took 42 months for all of the BCG group to achieve negativity. Immunotherapy appears to have a significant effect on the killing and clearance of bacilli and should be considered as an adjunct to chemotherapy, especially in bacilliferous lepromatous cases.

The nature of bones and joints: a new perspective

In human ontogeny recapitulating phylogeny, bones arrive late on the scene--long after neurogenesis, musculogenesis, organogenesis and so on are over--as islands of ossification in an ocean of collagen. This study confirms this developmental sequence by demonstrating, in cadavers, the rather independent nature of bone, to which nothing--muscle, tendon, ligament or articular cartilage--is attached. Bone is like the air in a tubeless tyre; it gives rigidity and shape to the tyre, and in return takes the shape of the tyre. The tibia, for example, is the bony tissue that is contained in tyre-like casing made of peritibial soft tissues whose inner limit is the periosteum, which continues proximally and distally as capsules of knee/ankle joint, and to which only are the articular cartilages of the knee and ankle attached, being clearly free from the bones. This study also exposes the truer nature of a joint wherein the articular cartilage assumes anatomic and physiologic significance hitherto unthought of.

Relapses in paucibacillary patients after treatment with three short-term regimens containing rifampin

Three multidrug regimens all containing rifampin and dapsone have been tried for the treatment of 278 cases of paucibacillary leprosy. Regimen I was the one recommended by the WHO Study Group. Regimen II was the same as Regimen I with depsone alone continued for a further 6 months. Regimen III was the same as Regimen II but rifampin was given daily for the first 7 days. The patients were comparable with regard to disease classification, lepromin status, bacteriological status, and number of lesions. As reported earlier, the disease inactivity rates by 1 year of treatment were much greater with Regimens II and III than with Regimen I (94% and 97% vs 76%). Early reaction was seen in 6% of those in Regimen III and in none in Regimens I and II. Late reaction was observed in 9% of those in Regimen I and none in Regimens II and III. During 3 1/2 years of follow up, 13% of the cases in Regimen I, 1% in Regimen II, and 2% in Regimen III relapsed. Since the patients in the three regimens were otherwise comparable, it is concluded that the high inactivity rate, low relapse rate (1%-2%), and no early or late reaction as observed in Regimen II patients were because of adequate treatment.