Effectiveness of multidrug therapy in multibacillary leprosy: a long-term follow-up of 34 multibacillary leprosy patients treated with multidrug regimens till skin smear negativity

The World Health Organization (WHO) Field Trials of multidrug therapy (MDT) started at Schieffelin Leprosy Research and Training Centre (SLR & IC), Karigiri, India in December 1981. The patients were treated with two MDT regimens. The first (regimen A) consisted of 600mg rifampicin and 300mg of clofazimine given under supervision on 2 consecutive days monthly, 225mg injection of acedapsone bimonthly and dapsone 100mg daily. The second regimen (regimen B) was the conventional MDT (WHO/MDT), rifampicin 600mg and clofazimine 300mg supervised once a month, dapsone 100mg and clofazimine 50mg daily, unsupervised. Both the regimens were administered for a minimum period of 2 years or until skin smear negativity, whichever occurred later. Thirty-four newly detected previously untreated MB patients, 16 of whom received regimen A and 18 regimen B, were reassessed. Both regimens were well accepted and well tolerated by the patients. Clofazimine discolouration was the only adverse effect of MDT seen in these patients. After completion of treatment with MDT, the patients were followed up for a total duration of 466 person-years with a mean of 13.7 +/- 1.4 years per patient. No relapse was seen.     

Prediction of 'highly skin smear positive' cases among MB leprosy patients using clinical parameters

Although 'highly skin smear positive' MB leprosy cases are known to be at high risk of relapse after release from treatment, and have been recommended to receive 'prolonged duration' MDT, government field-based control programmes without skin smear facilities have no simple alternative method to detect such cases. This study reports a significant prevalence of 'highly smear positive' cases amongst 2374 new multibacillary cases recently surveyed by skin smears in Nepal, and retrospectively analyses 555 newly detected, previously untreated BL and LL cases to identify clinical and laboratory parameters that may be associated with a 'highly positive skin smear'. While some parameters showed high sensitivity in predicting 'highly positive smear' status, none showed both high sensitivity and high specificity simultaneously.     

Role of slit skin smear examination in cutaneous T-cell lymphomas and other chronic dermatoses

The purpose of this study was to evaluate the utility of slit-skin smear examination in the diagnosis of various chronic dermatoses. The study included 24 patients with chronic dermatoses who presented to the skin outpatient department. Ten patients had idiopathic erythroderma, seven were diagnosed with airborne contact dermatitis, four had cutaneous T-cell lymphoma, two had chronic actinic dermatoses, and a single patient had panniculitis. Slit skin smears were obtained from all patients, stained with Leishman stain, and examined under microscope. Out of 24 patients, all four cases of cutaneous T-cell lymphoma showed abnormal cells suggestive of lymphomatous infiltration, two patients with airborne contact dermatitis showed reactive lymphocytes, and two idiopathic erythroderma cases showed numerous eosinophils in the smear. Slit skin smear examination is a simple rapid, decisive test in the diagnosis of cutaneous T-cell lymphoma. It is a useful screening test, especially in Sezary syndrome and diseases with specific skin infiltrate.     

Presence of Mycobacterium leprae in epidermal cells of lepromatous skin and its significance

A 49-year-old man with lepromatous leprosy treated with dapsone monotherapy for 12 years (1967 to 1979) reported in the hospital in 2003, with relapsed disease. A slit skin smear showed a bacteriological index of 4+. Biopsies from skin lesions before and after anti-leprosy therapy showed features of lepromatous leprosy. Both biopsies showed unusual features of bacillary clumps in epidermal cells demonstrating clearly that dissemination of M. leprae can take place even through unbroken skin. The presence of lepra bacilli in clumps in the epidermis is an indicator that the skin is a potential route of transmission of the disease.     

A clinical and bacteriological examination of Mycobacterium leprae in the epidermis and cutaneous appendages of patients with multibacillary leprosy.

In the specimens examined at Ryukyu University Hospital, acid-fast bacilli (AFB) were observed in the epidermis, cutaneous appendages and endothelial cells of capillaries. These specimens were taken from non-ulcerating skin lesions of patients with multibacillary leprosies such as LL and borderline lepromatous leprosy (BL). Of the 211 specimens examined, 23 (10.9%) were AFB-positive [AFB (+)] in the above mentioned skin regions. These AFB (+) samples were taken from nine leprosy patients; six cases (17 samples) of LL, two cases (5 samples) of BL, and one case (one sample) of BB. The AFB positive rate [AFB (+)-rate] in the above mentioned skin regions was high in the unmedicated LL sample (50.0%, 7/14) and low in the medicated mid-borderline leprosy (BB) samples (0.0%, 0/10). Particularly in the intraepidermal eccrine sweat duct (acrosyringium), a relatively high number of AFB were observed. The AFB (+)-rate appears likely to be higher in non-ulcering skin lesions with minor inflammation or in lesions with leprosy reaction than typical skin lesions such as papules, nodules, and infiltrated punched out skin lesions. Although the possibility that viable bacilli could be excreted from non-ulcerating skin lesions appeared to be small, these lesions were suspected of being a possible source of infection.     

鼻分泌物及皮肤组织中麻风菌及其PGL-1抗原的检测

为了更好地理解麻风菌鼻携带在麻风病传播、维持中的作用，以及运用鼻携带检测来评价麻风病防治效果，比较了PCR和Dot-ELISA／ECL平行检测32例活动性麻风患者、13例愈后者和143名麻风家内接触者鼻分泌物及皮肤组织中的麻风菌及其PGL-1抗原。结果显示，Dot-ELISA／ECL具有较好的敏感性、特异性，是一项适用于现场研究的简便、快速、经济的麻风流行病学工具。此外，用于免疫学试验，GVHP是一种吸附性好，适合于检测粘膜分泌物抗原的载体。     

Process of disintegration and degradation of M. leprae: study of tissue imprints and tissues

The existence, distribution and behaviour of degradation products of M. leprae in leprosy lesions were investigated in tissue specimens fixed in neutral formalin and embedded in paraffin. Cytopathologic findings using tissue imprints were unsatisfactory. Sections were stained with hematoxylin-eosin, acid-fast stains, silver methenamine and by an immunochemical (PAP) technique using serial paraffin sections. A comparison in respect of the distribution of the bacilli within the macrophages showed considerable differences between the superficial and deep granulomas. This corresponds roughly with the central, intermediary and peripheral locations. In a small granuloma seen in BL lesions, there were two zones: central and peripheral. In a large LL granuloma, three zones were seen, central, intermediary and peripheral zones. It is suggested that the degradation of disintegrated particles of bacilli might be due to the lysosymal activity of macrophages. The phagocytized bacilli are slowly degraded with long incubation periods, but the undigested debris remains inside the phagosomes. The chemical complexity of cytoplasm, cell wall and lipid fractions of M. leprae, and it is such that the lipid fractions of M. leprae mask some other antigenic components, which may be responsible for the cellular response and lysosymal production. According to our findings we believe that chemotherapy kills M. leprae but degraded products are not removed. These components are chemically complex and digested with difficulty. Lysosymal enzymes could be inhibited from productions by the bacterial debris or the lipid fractions could serve as a mask to delay lysosymal production in the cell. These aspects need further study.     

实时荧光定量PCR检测石蜡标本中麻风菌DNA

目的：评价实时定量荧光PCR(Real-time PCR)法检测石蜡标本中麻风菌DNA的应用价值。方法：根据基因库(GenBank)发表的M. leprae的全基因组序列,以一段重复序列(repetitive ele￣ment,RLEP)为扩增靶序列,合成引物和探针,构建质粒pGEMT-101作为标准品,用Real-time PCR对石蜡标本进行麻风菌DNA检测,并评价其敏感性。结果：对52例麻风患者的石蜡包埋组织标本麻风菌进行了检测,不同型别麻风(LL：8;BL：10;BT：28;TT：6)的石蜡标本检测阳性率分别为100％(8/8)、80％(8/10)、78.57％(22/28)、50％(3/6)。结论： Real-time PCR方法可在石蜡标本中快速灵敏的检测到麻风菌DNA。     

Detection of lepromatous leprosy patients shedding M. leprae in nasal droppings by enzyme immunoassay

Enzyme immunoassays (EIAs) for detection of lepromatous leprosy (LL) patients harbouring M. leprae in nasal mucosa are described. One EIA measures IgM antibodies against the synthetic disaccharide (ND-BSA) residue of phenolic glycolipid I of M. leprae, whereas the other titrates primarily IgG antibodies against sonicate supernatant antigens of Mycobacterium w. (M.w.). Fifty coded leprosy sera were analysed by EIAs under a double blind code. Amongst the 20 LL patients with positive nasal smear, 18 (90%) were positive in EIA based on ND-BSA, in comparison to 19 (95%) in EIA using M.w. antigens. The assays can be performed on fresh serum samples or on blood samples collected on filter paper discs. These assays can be useful for leprosy control programmes.     

Use of non-conventional antigen: M. habana in detecting M. leprae antibodies from leprosy patients and contacts in FLA-ABS test

An indirect immunofluorescent (FLA-ABS) test has been developed to detect M. leprae specific antibodies in the active and subclinical cases of leprosy. An antigenically related mycobacterium, M. habana, was used as an antigen to detect M. leprae specific antibodies in the sera samples of leprosy patients. A comparison was made with M. leprae antigen using same set of sera samples. M. habana is capable of detecting anti-M. leprae antibodies in the serum samples of leprosy patients, previously absorbed with various mycobacterial antigens, cardiolipin and lecithin, almost to the same percentage as M. leprae. Possible use of M. habana antigen as an alternative to M. leprae, in the serodiagnosis of leprosy, has been discussed.     

Induction of lepromin positivity by a candidate anti-leprosy vaccine Mycobacterium w in lepromin negative healthy contacts of multibacillary leprosy patients.

In a hospital based study, 362 household contacts of multibacillary leprosy patients were screened for evidence of leprosy and 54 (14.9%) were found to be having leprosy. The remaining 308 apparently healthy contacts were lepromin tested and 109 (35.4%) were observed to be negative to Mitsuda lepromin. M.w vaccine was administered intradermally to 95 of these 109 lepromin negative contacts. Sixty eight of them could be retested for lepromin A reactivity. Fifty six (82.35%) manifested lepromin conversion. The twelve subjects who did not show lepromin conversion, received a second dose of the vaccine, and eleven subsequently became lepromin positive. The overall lepromin conversion rate was thus 98.5% (67 out of 68). Follow-up of these contacts upto a period of 30 months did not demonstrate reversion of lepromin positivity back to negativity status. No untoward effects of vaccination were observed except for local ulceration at the site of vaccine administration.