Detection of IL-13, IL-10, and IL-6 in the leprosy skin lesions of patients during prednisolone treatment for type 1 (T1R) reactions

This study demonstrates the presence of IL-10 and IL-6, by immunohistochemistry, in the skin lesions of patients with Type 1 reactions. Fifteen patients with Type 1 reaction from Hyderabad, India were included in this study. They were all receiving standardized treatment for Type 1 reactions: a reducing course of daily oral prednisolone for 6 months. Biopsies were taken before treatment and during treatment at weeks 1, 4, and 6 months. IL-13 was observed in the lesions of most patients. By week 4 of treatment, the presence of IL-13, IL-10, and IL-6 in the lesions had decreased significantly. Although some patients showed significant clinical skin sign improvement within one week of therapy, no concomitant decrease or increase in any of the cytokines was observed at this time point. Interestingly, some cytokine activity within the lesions was observed after 6 months of treatment.

Molecular genotyping of a large, multicentric collection of tubercle bacilli indicates geographical partitioning of strain variation and has implications for global epidemiology of Mycobacterium tuberculosis

Tuberculosis continues to be a major killer disease, despite an all-out effort launched against it in the postgenomic era. We describe here the population structure of Mycobacterium tuberculosis strains, as revealed by a chromosome-wide scan of fluorescent amplified fragment length polymorphisms (FAFLPs), for more than 1,100 independent isolates from 11 different countries. The bacterial strains were genotyped based on a total of 136 +/- 1 different FAFLP markers at the genome sequence interface, with details on IS6110 profiles, drug resistance status, clinicopathological observations, and host status integrated into the analysis process. The strains were found to cluster with possible geographic affinities, including the parameters of host species type, IS6110 profile, and drug susceptibility status. Of the five most commonly amplified fragment sets (or amplitypes), type A predominated in strains of mixed origin, deposited in The Netherlands; type B was exclusively observed for Indian isolates; type C was found mainly in strains from Peru and Australia; and types D and E predominated in European strains from France and Italy. The amplitypes were independent of certain large sequence polymorphisms representing two important deletions, TbD1 and Rd9. It appears that M. tuberculosis has a high genomic diversity with a possible geographic evolution. This may have occurred due to specific genomic deletions and synonymous substitutions selected rigorously against host defenses and environmental stresses on an evolutionary timescale. The genotypic data reported here are additionally significant for genotype-phenotype correlations and for determining whether pathogen diversity is a reflection f the host population diversity.

Comparative proteomics of the Mycobacterium leprae binding protein myelin P0: its implication in leprosy and other neurodegenerative diseases

Mycobacterium leprae, the causative agent of leprosy invades Schwann cells of the peripheral nerves leading to nerve damage and disfigurement, which is the hallmark of the disease. Wet experiments have shown that M. leprae binds to a major peripheral nerve protein, the myelin P zero (P0). This protein is specific to peripheral nerve and may be important in the initial step of M. leprae binding and invasion of Schwann cells which is the feature of leprosy. Though the receptors on Schawann cells, cytokines, chemokines and antibodies to M. leprae have been identified the molecular mechanism of nerve damage and neurodegeneration is not clearly defined. Recently pathogen and host protein/nucleotide sequence similarities (molecular mimicry) have been implicated in neurodegenerative diseases. The approach of the present study is to utilise bioinformatic tools to understand leprosy nerve damage by carrying out sequence and structural similarity searches of myelin P0 with leproma and other genomic database. Since myelin P0 is unique to peripheral nerve, its sequence and structural similarities in other neuropathogens have also been noted. Comparison of myelin P0 with the M. leprae proteins revealed two characterised proteins, Ferrodoxin NADP reductase and a conserved membrane protein, which showed similarity to the query sequence. Comparison with the entire genomic database (www.ncbi.nlm.nih.gov) by basic local alignment search tool for proteins (BLASTP) and fold classification of structure-structure alignment of proteins (FSSP) searches revealed that myelin P0 had sequence/structural similarities to the poliovirus receptor, coxsackie-adenovirus receptor, anthrax protective antigen, diphtheria toxin, herpes simplex virus, HIV gag-1 peptide, and gp120 among others. These proteins are known to be associated directly or indirectly with neruodegeneration. Sequence and structural similarities to the immunoglobin regions of myelin P0 could have implications in host-pathogen interactions, as it has homophilic adhesive properties. Although these observed similarities are not highly significant in their percentage identity, they could be functionally important in molecular mimicry, receptor binding and cell signaling events involved in neurodegeneration.

Expression of CC and CXC chemokines and chemokine receptors in human leprosy skin lesions

We have investigated the expression of chemokines and their receptors in leprosy skin lesions using immunohistochemistry. Skin biopsies from 25 leprosy patients across the leprosy spectrum, 11 patients undergoing type I reversal reactions and four normal donors were immunostained by ABC peroxidase method using antibodies against CC and CXC chemokines and their receptors. Using an in situ hybridization technique we have also studied the expression of monocyte chemoattractant protein 1 (MCP-1), RANTES and interleukin (IL)-8 chemokines mRNA in leprosy skin lesions. Chemokines and receptor expression was detected in all leprosy skin biopsies. Expression of CC chemokines MCP-1 (P < 0.01) and RANTES (P < 0.01) were elevated significantly in borderline tuberculoid leprosy in reversal reaction compared to non-reactional borderline tuberculoid leprosy, but there was no difference in the expression of IL-8 chemokine. Surprisingly, there was no significant difference in the expression of CC (CCR2 and CCR5) and CXC (CXCR2) chemokine receptors across the leprosy spectrum. Similarly, there was no significant difference in the expression of mRNA for MCP-1, regulated upon activation normal T cell expressed and secreted (RANTES) and IL-8 chemokines. Here, the presence of a neutrophil chemoattractant IL-8 in leprosy lesions, which do not contain neutrophils, suggests strongly a role of IL-8 as a monocyte and lymphocyte recruiter in leprosy lesions. These results suggest that the chemokines and their receptors, which are known to chemoattract T lymphocytes and macrophages, are involved in assembling the cellular infiltrate found in lesions across the leprosy spectrum.

Mycobacterium leprae binds to a major human peripheral nerve glycoprotein myelin P zero (P0)

We have previously shown that a major phosphorylated 25-kDa glycoprotein of the human peripheral nerve binds to Mycobacterium leprae. In the present study, we confirm that the 25-kDa glycoprotein of the human peripheral nerve is myelin P zero (P0) by immunoprecipitation and Western blot experiments using monoclonal antibodies to myelin P0. Immunohistochemical studies on human nerve using these antibodies to myelin P0 exhibited a strong immunoreactivity to the myelin and Schwann cells. Myelin P0 is a peripheral nerve specific protein; therefore it could likely be one of the key target molecules for M. leprae binding/internalization or even contact-dependent demyelination. This finding of M. leprae binding to myelin P0 adds to the present understanding on neural predilection of M. leprae.

Childhood leprosy in an urban clinic, Hyderabad, India: clinical presentation and the role of household contacts

A retrospective case note study was done of children below the age of 14 years who attended Dhoolpet Leprosy Research Centre (DLRC) over the decade 1990-1999. The aim of the study was to describe the pattern of clinical presentation, the role of household or near neighbour contacts and the incidence of neuritis and reactions. In all, 3118 leprosy patients were registered during this period, of whom 306 were children [182 (60%) male]; 95 children had a single patch, 159 had five or fewer than five patches and 37 had multiple patches. The youngest case detected was 9 months old. The spectrum of leprosy in these children was: TT 62 (20.3%); BT 203 (66.3%); BB 3 (1%); BL 23 (7.5%); LL 5 (1.6%) and PNL 10 (3.3%). Twenty-nine cases (9.4%) were smear positive. Ninety-one children (29.7%) developed a reaction, 86 type I and five type II. A history of contact was present in 119 (38.8%) cases, family contact in 113 (95%) and other than family in six (5%). Classification of the contact was available in only 60 patients. Among the contacts of the index case, 21 (35%) suffered from PB leprosy and 39 (65%) from MB leprosy. All contacts were from the immediate family. This study shows that childhood leprosy cases continue to present in significant numbers to this outpatient clinic. There is a high level of family contact with leprosy in these cases, strengthening the strategy of screening children in leprosy-affected households. The high incidence of reactions and nerve damage in children emphasizes the importance of early detection and treatment.

Histological changes in the nerve, skin and nasal mucosa of patients with primary neuritic leprosy

Primary neuritic leprosy (PNL) presents as a peripheral neuropathy with no visible skin patches and skin smears negative for acid fast bacilli. The pathogenesis of PNL is poorly understood. The aim of the study was to document the histological changes in the nerve, apparently normal skin and nasal mucosa in PNL and to study its significance to the pathogenesis of leprosy lesions. The study is based on a cohort of 208 PNL patients registered at the Schieffelin Leprosy Research and Training Centre, Karigiri. All patients had a nerve biopsy, 196 had a skin biopsy and 39 had a nasal mucosal biopsy. The findings reveal that PNL patients exhibit a spectrum of disease histologically in the nerve ranging from lepromatous to tuberculoid leprosy with a significant proportion (46%) manifesting a multibacillary leprosy histology. Findings in the apparently normal skin and nasal mucosa reveal that there are widespread changes due to leprosy in tissues such as the skin and nasal mucosa even when the disease appears clinically confined to a few nerves. PNL may be an early stage in the pathogenesis of the disease before the appearance of skin lesions. The number of nerves enlarged and lepromin status did not give any clue to the nature of underlying disease.

Immunohistochemical analysis of cellular infiltrate and gamma interferon, interleukin-12, and inducible nitric oxide synthase expression in leprosy type 1 (reversal) reactions before and during prednisolone treatment

The effects of prednisolone treatment on the cellularity and cytokine (gamma interferon, interleukin-12, and inducible nitric oxide synthase) profiles of leprosy skin type 1 (reversal) reactions were studied using immunohistochemistry. Skin biopsies were taken from 15 patients with leprosy type 1 (reversal) reactions at days 0, 7, 28, and 180 after the start of steroid treatment. Prednisolone treatment had little effect at day 7, but by day 28 significant decreases were found in cytokine levels. Some patients maintained cytokine production at days 28 and 180. These results illustrate the strong Th1 profile of type 1 reactional lesions, the slow response to steroid therapy, and continuing activity at 180 days.

Bacteriological study of pus isolates from neuropathic plantar ulcers associated with acute inflammatory phase

In this retrospective study, sensitivity of organisms cultured from ulcers of leprosy patients without and with diabetes mellitus, diabetic patients without leprosy and patients with ulcers from other causes was examined. The profile of organisms grown from these groups of patients did not differ significantly. However, there was a high prevalence of organisms like Proteus, E. coli and Enterococcus in the ulcers of leprosy patients indicating faecal contamination of the ulcers. Co-trimaxazole and tetracycline were of little value in the treatment of these ulcers. We therefore recommend that in situations where there is no culture facility, the patients be started on a course of penicillin and gentamycin. If these antibiotics fail, it would be necessary to use more advanced antibiotics like norfloxacin, amikacin and ciprofloxacin.

Histological studies in primary neuritic leprosy: changes in the nasal mucosa

The nasal mucosae of 39 cases of primary neuritic leprosy (PNL) registered at Karigiri were studied histologically to determine nasal mucosal involvement in PNL and its relevance to the pathogenesis of the disease. Specific changes of leprosy were seen in 20 (51%) biopsies, ranging from macrophage granulomas with acid fast bacilli, to epithelioid granulomas and nerve inflammation. The remaining biopsies revealed chronic inflammatory changes of the mucosa or mild non-specific nerve changes. These findings show that there are widespread effects of the disease even in PNL patients in whom the disease is believed to be confined to the peripheral nerves. The findings also show that early leprosy involvement can be found in the nasal mucosa even before lesions become apparent in the skin or other parts of the body. The nasal mucosa could be one of the sites for the primary lesion in leprosy. Clinical and histological examination of the nasal mucosa may be useful and important in the early diagnosis of leprosy and especially in contacts.

Histological studies in primary neuritic leprosy: changes in the apparently normal skin

The visually normal skin of 196 patients diagnosed clinically to have primary neuritic leprosy was studied histologically to determine whether there were any specific changes due to the disease in this site. Histological changes due to leprosy were seen in 32.1% of the patients, and included, indeterminate leprosy in 19.4%, borderline tuberculoid leprosy in 6.6% and borderline lepromatous leprosy in 6.1%. The remaining biopsies showed mild non-specific dermal inflammation, mild nerve changes or no significant lesion. The nerve inflammation and/or granulomas were mostly in the deep dermal nerves or neurovascular complexes. This study shows that there is a cutaneous component to primary neuritic leprosy and the disease is not totally confined to nerves. The absence of visible hypopigmented patches in these patients is probably related to the deep location of the dermal inflammation.

Quantitative assessment of facial sensation in leprosy

The trigeminal and great auricular nerves which supply sensation to the face are affected in leprosy. No objective sensory testing methods have been devised for testing sensation in the face. Testing for corneal sensation to ascertain trigeminal nerve or visualization and palpation of the great auricular nerve alone may not be enough to establish the involvement of these nerves. In a sample of leprosy patients, face sensation threshold measurements were done using a set of three Semmes-Weinstein (SW) monofilaments that gave a force of 0.05-0.07, 0.2 and 2 g. Sensation was tested by three examiners and intra- and inter-observer testing was used as a means to validate the findings. Within the limitations of this study, the results indicate that use of SW monofilaments is a fairly reliable and repeatable method for sensory testing in the face. During follow up, a single filament with a force of 0.5-0.7 g (2.83 marking number in SW filament or any other filament with a corresponding gram force) could be used to assess sensation. A simple procedure of quantifying sensation in these nerves is suggested. A method to incorporate trigeminal or great auricular nerve sensory testing into the existing sensory assessment charts is also discussed.

M. leprae binds to a 28-30-kDa phosphorylated glycoprotein of rat peripheral nerve

To understand Mycobacterium leprae-peripheral nerve interaction, we have investigated the binding of M. leprae to rat peripheral nerve proteins in an in vitro model using 32P-phosphorylated proteins of the peripheral nerve. Intact M. leprae binds to a major phosphorylated protein of 28-30 kDa and, to a minor extent, to a few proteins of molecular weight 45-55 kDa. This binding was more specific for M. leprae since only insignificant binding was observed with other bacteria, such as M. bovis or Escherichia coli. M. leprae did not show binding to several phosphorylated proteins of the rat brain. The 28-30-kDa binding protein of the rat peripheral nerve was found to be a glycoprotein by concanavalin A-Sepharose column chromatography.

Clinical and histopathological activity in paucibacillary leprosy patients after fixed-duration multidrug therapy

In 37 clinically-diagnosed borderline-tuberculoid (BT) leprosy patients skin biopsies were done prior to starting multidrug therapy (MDT) and at the end of 6 months therapy. Clinical and histopathological activity, graded as active, resolving and inactive, were studied at the end of 6 months of MDT. Of the 37 clinically-diagnosed BT patients 24 could be confirmed by histopathology as having BT leprosy, while the other 13 biopsies showed features of indeterminate (I) leprosy. After 6 months of MDT, out of the 24 histopathologically-confirmed BT patients, 4 (17%) showed clinical activity and 8 (33%) showed histopathological activity. Of the 13 histopathologically-diagnosed indeterminate cases all were clinically inactive but histological activity persisted in 3 cases (23%). Out of the 37 clinically-diagnosed BT patients 3 showed both clinical and histopathological activity at the end of MDT. This study emphasizes the importance of performing histopathological examinations on leprosy patients undergoing research studies for the confirmation of diagnosis and for proper classification of the disease. The histopathological activity that outlasts the MDT may be due to the bacillary fragments that persist but clinical activity coupled with histopathological activity seen in 3 patients at the end of 6 months may foreshadow a relapse and these patients and others like them need to be followed up for longer durations.

Multibacillary nerve histology in clinically diagnosed borderline tuberculoid leprosy patients

The classification of leprosy into multibacillary (MB) and paucibacillary (PB) patients in almost all clinics is entirely dependent on clinical examination. In a study of 21 patients clinically classified as borderline tuberculoid (BT) and, therefore, belonging to the PB group, skin smears and skin and nerve biopsies were examined. Four patients did not have any histopathological evidence of leprosy. Skin smears showed that 1 patient was positive for acid-fast bacilli (AFB), 2 skin biopsies belonged to the borderline lepromatous (BL) category and showed AFB in their lesions, and AFB were present in 10 nerve biopsies classified as BL. It is possible that reported relapses among PB patients may be in those patients with demonstrable AFB in the lesions, including nerves. A careful follow-up study of this particular group of patients after PB multidrug therapy is suggested to resolve this question.

Detection of superoxide dismutase isozymes in normal and X-irradiated chick amniotic fluid by using isoelectric focussing

Isoelectric focussing of amniotic fluid of chick system over pH gradient of 4-6 revealed presence of 8 superoxide dismutases. The superoxide dismutase (SOD) isozymes were identified as one major isozyme and other seven were minor ones. Higher expression of SOD (major isozyme) with exposure of 1000 R was studied. The isoelectric point (pI) of major SOD isozyme in control (5) differs from radiation exposed samples (5.12). Hence in radiation exposed amniotic fluid showed more pronounced SOD major isozyme, than control amniotic fluid. It is clearly evident that the SOD isozyme with X-irradiation having different isoelectric points, may lead to modification of the amino acid composition and charges of amino acids in the protein structure of SOD. So, the higher SOD isozyme expression has a role in defence action against free radical damage by X-irradiation during embryonic development.

Treatment of recent facial nerve damage with lagophthalmos, using a semistandardized steroid regimen

Twenty-seven patients with borderline leprosy and facial nerve damage of less than or equal to 6 months duration (36 eyes) were treated with a semistandardized regimen of steroids (the average starting dose was 25-30 mg, duration 5-6 months) on an outpatient basis. Red and raised reactive patches were usually present in the upper malar area or around the eye(s) in patients with recent lagophthalmos. The lid gap was measured in millimetres during gentle and strong closure. After completion of the steroid course 75% of the eyes had complete closure or only a slight gap of less than or equal to 2 mm on gentle closure. Steroids were found to be beneficial and safe, in the dosage that we prescribed.

The significance of facial patches and type I reaction for the development of facial nerve damage in leprosy. A retrospective study among 1226 paucibacillary leprosy patients

Charts of 1226 paucibacillary leprosy patients, registered between 1982 and 1987 were reviewed for recent facial nerve damage, facial patches and the presence of Type I reaction. Twenty-six (2.1%) patients with recent lagophthalmos were identified. In a great majority (85%) patients with recent lagophthalmos showed significant patches over the malar region or around the eye, at the same side as the nerve damage together with clinical signs of Type I reaction. This combination of significant patches in certain locations and Type I reaction seems to be a pre-condition for facial nerve damage. The clinical implication is that a small group of patients may be identified, who are at risk of facial nerve damage. By examining these patients more carefully it will be possible to detect nerve damage early and to prevent permanent damage of the facial nerve by timely treatment with an appropriate steroid regimen.