Immunostimulatory activity of major membrane protein-II from Mycobacterium leprae

We examined the antigenicity of an immunomodulatory protein, major membrane protein (MMP)-II, from Mycobacterium leprae, since host defense against M. leprae largely depends on adaptive immunity. Both unprimed and memory T cells from healthy individuals were stimulated by autologous MMP-II-pulsed monocyte-derived dendritic cells (DCs) to produce IFN-gamma. The DC-mediated IFN-gamma production was dependent on the expression of MHC, CD86, and MMP-II antigens. Memory T cells from paucibacillary (PB) leprosy more extensively responded to MMP-II-pulsed DCs than T cells from healthy individuals, while comparable IFN-gamma was produced by unprimed T cells. Memory T cells from multibacillary leprosy, which are normally believed to be anergic, were activated similarly to those from healthy individuals by MMP-II-pulsed DCs. These results suggest that memory T cells from PB leprosy are primed with MMP-II prior to the manifestation of the disease, and MMP-II is highly antigenic in terms of activation of adaptive immunity.

Clinical manifestations, diagnosis and classification of leprosy

Mycobacterium leprae, the causative organism of leprosy is slow-growing and the reason is its long incubation period of 2-4 years. Males are predominantly affected and deformity is produced in less than 2% of people affected with the disease. The disease manifests in the skin as macules, papules, nodules, plaques or infiltration. Hypopigmented or erythematous skin patches with definite sensory deficit is one of the clinical cardinal signs by which one can make a definite diagnosis. Demonstration of bacilli in the slit skin smear is the bacteriological cardinal sign used to make definite diagnosis of leprosy. Involvement of common cutaneous nerves with thickening and/or tenderness with its dysfunction is the second clinical cardinal sign used to diagnose leprosy. Diagnosis can be made by eliciting definite sensory deficit in the skin lesions (other than nodules and infiltration). In the absence of two clinical cardinal signs and when there is a strong suspicion of leprosy, slit skin smear should be taken from both ear lobes and one of the lesions for demonstration of acid-test bacilli. Clinical classification is based on characteristics like number of lesions, their margin, sensory deficit, satellite lesions, symmetry of lesions, central healing and scaling. Up to 5 lesions are grouped under paucibacillary and six and more are grouped under multibacillary leprosy.

Validity of the WHO operational classification and value of other clinical signs in the classification of leprosy

The objective of this study is to examine the validity of the WHO operational classification using skin smear results as the gold standard and explore the value of additional clinical signs independently and in combination with the WHO classification. Between 1985 and 2000, 5439 new untreated leprosy patients were registered at the Schieffelin Leprosy Research and Training Center, Karigiri. They were classified according to the Ridley Jopling classification as well as WHO operational classification based on the number of skin lesions. The sensitivity and specificity of the WHO operational classification tested, using skin smear results as the gold standard, was found to be 88.6% and 86.7% respectively. The Receiver Operator Characteristic (ROC) curve confirms that the best option for sensitivity and specificity is a cut off of 6 and more lesions for MB. The validity of the number of enlarged nerves and size of the largest skin lesion as independent criteria to classify patients was found to be poor. Addition of three enlarged trunk nerves to the WHO classification improved its sensitivity to 91.4%, while the specificity remained almost unchanged at 85.3%. Addition of the size of the largest skin lesion to the WHO classification reduced its validity considerably. The study concludes that the WHO recommendation of using six and more lesions for classifying a patient as MB is the best option available at the moment, and calls for further research to identify other clinical criteria that have a better validity and could be easily applied in the field.

A comparative study between 12 and 24-dose therapeutic regimens for multibacillary leprosy patients

A comparative study was made of the initial and final bacterial indices (BIs) of 213 MB leprosy patients who had been administered 12-dose (Group 1/128 patients) and 24-dose (Group 2/85 patients) World Health Organization multi-drug therapy to measure the effectiveness of both treatment regimens. All patients were evaluated at the beginning of treatment, at 12 months, and again after 24 months had elapsed. Decline in BI values and average BIs at 24 months were found to be similar for both groups. Moreover, no statistical difference between the two treatment regimens was found in the frequency rate of reaction.

Incidence of neuritis among paucibacillary leprosy patients during treatment and surveillance

A cohort study was done on 180 patients receiving the standard WHO PB-MDT regimen at the TLM Hospital in Kolkata, during MDT and 2 years of surveillance to determine the incidence of neuritis. Neuritis occurred in only 2 out of the 180 patients, confirming that the current WHO treatment for PB-MDT is attendant with minimal risk of neuritis. No risk factors were found, except pregnancy in a female patient. While addition of clofazimine in the new U-MDT under trial might take care of the occasional neuritis, further clinical research might be useful to identify sub-groups of PB patients at risk of neuritis.

Leprosy: a primer for Canadian physicians

Leprosy is a rare but serious infectious disease caused by Mycobacterium leprae. While global prevalence of the disease is decreasing, increasing rates of immigration from countries where leprosy is endemic have led to the recognition of this illness in North America. Classically, leprosy presents as hypopigmented cutaneous macules along with sensory and motor peripheral neuropathies, although the clinical manifestations vary along a disease spectrum. In addition to primary infection, patients may undergo a "reaction," an acute inflammatory response to the mycobacterium, which leads to pain and erythema of skin lesions and dangerous neuritis. Reactions can occur at any time during the course of leprosy, but they tend to be precipitated by treatment. They are a significant cause of impaired quality of life due to marked nerve damage and thus warrant prompt intervention. Although leprosy may have a protracted onset and be difficult to recognize, cure is achievable with appropriate multidrug therapy. Because untreated leprosy can result in permanent, irreversible nerve damage and secondary transmission, early diagnosis and treatment are essential to minimize morbidity.

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.

A clinical study of the involvement of cranial nerves in leprosy

A clinical descriptive study was conducted to assess the frequency and pattern of involvement of cranial nerves in leprosy and to study the relationship of cranial nerve involvement with a leprosy patch or patches on facial skin. One hundred consecutive patients of leprosy, diagnosed by clinical features and/or slit skin smear and histopathology, were studied; of these, 22 patients had cranial nerve involvement. The mean age of patients with cranial nerve involvement was 41.2 years. 16 patients (72.7%) with cranial nerve involvement were in the age-group of 20-49 years. The male-to-female ratio was 3.4:1. The mean duration of the disease in these patients was 5.73 years. The duration of the disease in the majority of patients with cranial nerve involvement was less than 5 years. Impairment of cranial nerves was seen in 12 BT patients, 6 BL patients, and 4 LL patients. No significant difference was noted between involvement of cranial nerves in PB and MB patients. Among the cranial nerves, facial nerve was the most common nerve involved (10/22), followed by olfactory (9/22), trigeminal (7/22) and auditory (3/22) nerves. Among the risk factors, it was found that facial nerve impairment was significantly associated with facial patch(es) and also type 1 lepra reaction.

Prevalence of leprosy among household contacts of leprosy cases in western Orissa

The prevalence rate of leprosy among household contacts is an important epidemiological indicator in the character and trend of the disease. During the period January 2001 to December 2002, families of 400 primary cases were studied to detect contact (secondary) cases. Seventy-two cases were detected from 54 families; of these 72 cases, 45 (62.5%) were in the paediatric age-group (0-14 years) and of these 45.8% belonged to 6-14 years group. Out of the 72 cases, there were more (58) of paucibacillary (PNL+I+TT+BT) cases. Secondary cases were significantly high when there was lepromatous type of leprosy in the family. The attack rate among those exposed to paucibacillary type (TT, BT) of leprosy, though much less, was still observed. The influence of duration of contact revealed that a maximum number of cases (N=43, 59.7%) acquired the disease during 0-6 years of contact. A majority of the patients belonged to low-income groups, were illiterate and lived in extended families. The father was the source case for most of the secondary cases (N=41, 57%). Conjugal leprosy was very rare. The results of the study points to the fact that PB leprosy is still a potential source of infection and cannot be ignored. It is important to evolve a hospital-based surveillance programme for contacts of leprosy patients since early detection and treatment of contacts are important measures for reducing the reservoir of infection in the community.

[Generalized adenopathy as a manifestation of type 2 reactional leprosy]

Generalized adenopathy as a manifestation of type 2 reactional leprosy Leprosy patient's reactions are severe clinical manifestations of acute inflammation of chronic lesions, capable of producing irreversible and invalidating damage. We studied a 46 year-old man with a type 2 leprosy reaction, who presented fever, cutaneous nodules, nasal obstruction and generalized adenopathy. The hemogram showed leucocytosis with neutrophilia. None of the initial diagnoses included leprosy. A lymph node biopsy revealed extensive necrotic areas infiltrated with polymorphonuclear lymphocytes, and foamy macrophages. Eosinophylic necrosis and thrombosis of venules with lymphoid nodule depletion was also in evidence. Ziehl Neelsen stain was not done, but the Gomori stain clearly showed Hansen's bacilli. These were were not detected by the pathologist and therefore a final diagnosis was not provided. Twenty months later, the patient presented similar symptoms, but with more generalized lymphadenopathy and presence of cutaneous nodules. Nodule biopsy showed lepromatous leprosy with erythema nodusum leprosum or type 2 reaction. Polychemotherapy treatment and anti-reaction treatment with thalidomide cured the patient. No sequelae were noted in 3 years following the treatment. A literature review of the type 2 reaction in leprosy is provided, including discussion of risk factors, histopathology, differential diagnosis for leprosy adenopathy, pathogenesis, prognosis, and treatment. Type 2 leprosy must be treated immediately upon diagnosis as it can cause serious and permanent tissue damage. As had occurred in the above patient, the disease can proceed with generalized and symptomatic lymphadenopathy.

Assessing socio-economic factors in relation to stigmatization, impairment status, and selection for socio-economic rehabilitation: a 1-year cohort of new leprosy cases in north Bangladesh

The current leprosy elimination strategy focuses almost exclusively on delivery of leprosy diagnostic services and multi-drug treatment (MDT). However, the specific problems of people newly diagnosed with leprosy or cured with MDT primarily relate to impairment of nerve function and social and economic consequences of the diagnosis of leprosy. This study was carried out to investigate the relation between socio-economic factors and the development of nerve impairments and stigma. In addition the relation between socio-economic factors and selection for socio-economic assistance was studied. The study population was a cohort of 2364 newly diagnosed people with leprosy in rural Bangladesh in 1996, including 42.5% women, with an overall mean age of 31.4 years. Three hundred and sixty people (15.2%) had WHO grade 1 or 2 disability identified at diagnosis, and 50 (2.1%) had stigma identified on interview at home visit conducted within one month of diagnosis. One hundred and eighty-eight people (8%) were selected for specific assistance for rehabilitation, primarily interest-free loans for income generating activities or vocational training. Factors independently associated with WHO grade 1 or 2 disability at diagnosis were multibacillary (MB) classification, adult status, and manual occupations. Smear positivity, female sex, and the presence of dependents were associated with an increase in the experience of stigma. The presence of nerve impairments and stigma, as well as several indices of poverty were clearly associated with selection for inclusion in an integrated program for socio-economic assistance. An increased focus by leprosy services on the socio-economic factors associated with poorer physical and social outcomes is recommended. Where adequate finances and trained staff are available, efforts could be made to identify those at higher risk of poor outcomes, and to provide or to mobilize appropriately targeted socio-economic interventions.

Simple and fast lateral flow test for classification of leprosy patients and identification of contacts with high risk of developing leprosy

The interruption of leprosy transmission is one of the main challenges for leprosy control programs since no consistent evidence exists that transmission has been reduced after the introduction of multidrug therapy. Sources of infection are primarily people with high loads of bacteria with or without clinical signs of leprosy. The availability of a simple test system for the detection of antibodies to phenolic glycolipid-I (PGL-I) of Mycobacterium leprae to identify these individuals may be important in the prevention of transmission. We have developed a lateral flow assay, the ML Flow test, for the detection of antibodies to PGL-I which takes only 10 min to perform. An agreement of 91% was observed between enzyme-linked immunosorbent assay and our test; the agreement beyond chance (kappa value) was 0.77. We evaluated the use of whole blood by comparing 539 blood and serum samples from an area of high endemicity. The observed agreement was 85.9% (kappa = 0.70). Storage of the lateral flow test and the running buffer at 28 degrees C for up to 1 year did not influence the results of the assay. The sensitivity of the ML Flow test in correctly classifying MB patients was 97.4%. The specificity of the ML Flow test, based on the results of the control group, was 90.2%. The ML Flow test is a fast and easy-to-perform method for the detection of immunoglobulin M antibodies to PGL-I of M. leprae. It does not require any special equipment, and the highly stable reagents make the test robust and suitable for use in tropical countries.

[Leprosy in Brazil]

Leprosy or Hansen's disease is a chronic infectious disease caused by the Mycobacterium leprae. The skin and nervous manifestations of the disease present a singular clinical picture that is easily recognized. After India, Brazil still is the second country with the greatest number of cases in the world. Around 94% of the known cases and 94% of the new cases reported in America, come from Brazil. The disease presents itself in two well-defined stable and opposite poles (lepromatous and tuberculoid) and two unstable groups (indeterminate and dimorphic). The spectrum of presentation of the disease may also be classified as: tuberculoid tuberculoid (TT), borderline tuberculoid (BT), borderline borderline (BB), borderline lepromatous (BL) and lepromatous lepromatous (LL). The finding of acid fast bacillus in tissue is the most useful method of diagnosis. The effective treatment of leprosy includes the use of specific therapy, suppression of lepra reactions, prevention of physical incapacity, and physical and psychosocial rehabilitation. Chemotherapy with rifampin, dapsone and clofazimine have produced very good results and the control of the disease in Brazil in the foreseeable future is likely.

Recent advances in the treatment of leprosy

Leprosy, a chronic infectious disease caused by Mycobacterium leprae, was identified by G. H. A. Hansen in 1873. The different clinical presentations of the disease are determined by the quality of the host immune response. The bacteria have affinity for the peripheral nerves and are likely the cause of neuropathy, a cardinal manifestation of the disease. WHO recommends a protocol of multidrug therapy (MDT), which effectively controls the disease, hence contributing to the global elimination program. Early detection of leprosy and treatment by MDT are the most important steps in preventing deformity and disability.

[Evaluation of the clinical classification of new cases of leprosy. Study conducted at the Marchoux Institute in Bamako, Mali]

INTRODUCTION

The difficulties related to the bacilloscopic diagnosis of leprosy, providing a more reliable classification of cases, in 1995 led the WHO to recommend the use of a new classification, in endemic countries, based on clinical criteria alone, in order to simplify the poly-chemotherapeutic regimens. According to our experience in the Marchoux Institute, this classification may lead to errors in diagnosis through overzealous or mis-interpretation of the two forms of leprosy. The aim of our study was to evaluate the concordance between this clinical classification and that based on a bacilloscopic examination.

PATIENTS AND METHODS

We conducted a descriptive study of new cases of leprosy seen at the Marchoux Institute, without distinction in gender or age, from January to December 2000. All the patients included underwent clinical examination and a bacilloscopic exploration to provide a double classification. The concordance between the two classifications was assessed using the Kappa test.

RESULTS

Two hundred new cases of leprosy were included. Out of 126 clinically multi-bacillary cases, 61 were confirmed bacteriologically, and 65 were false positives. Out of 74 clinical cases with few bacilli, 2 were bacteriologically multi-bacilli. The concordance between the two classifications was average (Kappa=0.40). There was a significant difference between the percentages of multi-bacilli observed in both classifications (p<10(-8)).

DISCUSSION

The clinical classification may well overestimate the multi-bacillary form. In the absence of a reliable bacilloscopic apparatus, a more detailed clinical classification of leprosy forms must be developed.

[Multibacillary leprosy in Tyrol]

Five cases of multibacillary leprosy have been diagnosed in a period of 15 years (1987-2001) at the outpatient Department of Neurology of the University Hospital Innsbruck. All patients presented with dermatological and mild to severe polyneuropathic signs and symptoms. 4/5 patients recovered fully, whereas 1 patient with an initially severe polyneuropathy showed persistent polyneuropathy as long-term sequela. The prevalence of leprosy in the catchment area of the Department of Neurology, University Hospital Innsbruck (comprising the entire province of Tyrol--650,000 inhabitants) is to be calculated as 0.5/1 million. The incidence of newly diagnosed leprosy within this province of Tyrol is 0.04/100,000/year. The aim of the presentation of these 5 patients is--beside the epidemiologic aspect--to alert all neurologists and dermatologists that this disease still exists--despite decreasing prevalence and incidence rates on a global scale; this is of particular importance since neurological long-term sequelae can only be avoided by early diagnosis.

Segregation of HLA/TNF region is linked to leprosy clinical spectrum in families displaying mixed leprosy subtypes

Each year an estimated 600000 new leprosy cases are diagnosed worldwide. The spectrum of the disease varies widely from limited tuberculoid forms to extensive lepromatous forms. A measure of the risk to develop lepromatous forms of leprosy is provided by the extent of skin reactivity to lepromin (Mitsuda reaction). To address a postulated oligogenic control of leprosy pathogenesis, we investigated in the present study linkage of leprosy susceptibility, leprosy clinical subtypes, and extent of the Mitsuda reaction to six chromosomal regions carrying known or suspected leprosy susceptibility loci. The only significant result obtained was linkage of leprosy clinical subtype to the HLA/TNF region on human chromosome 6p21 (P(corrected)=0.00126). In addition, we established that within the same family different HLA/TNF haplotypes segregate into patients with different leprosy subtypes directly demonstrating the importance of this genome region for the control of clinical leprosy presentation.