Postgenomic Mycobacterium leprae antigens for cellular and serological diagnosis of M. leprae exposure, infection and leprosy disease

Due to changes in leprosy control programs and the special expertise required for diagnosis, the need for simple rapid diagnostic tests that could be applied in non-expert settings may now be greater than ever before. Since the sequencing of the M. leprae genome, many research groups have investigated the potential of M. leprae antigens in either serologic or cell mediated assays. Here we provide an overview of the nearly 200 recombinant single proteins that were investigated during the last decade for their potential to be applied in field-friendly tests for the early diagnosis of leprosy.     

麻风菌抗原诱导IL-12产生的体外研究

目的:检测麻风菌不同抗原脂蛋白诱导单个核细胞(PBMC)IL-12p40分泌水平.方法:以麻风菌不同抗原刺激体外培养的少菌型(PB)、多菌型(MB)麻风患者及健康接触者PBMC,加入或不加外源性IFN-γ共培养,ELISA检测培养上清的IL-12p40分泌水平.结果:(1)麻风菌胞浆抗原(MLSA)和麻风菌33KDa脂蛋白可诱导健康接触者、PB患者PBMC分泌IL-12p40;(2)外源性IFN-γ可上调健康接触者和PB患者PBMC分泌IL-12p40水平.结论:麻风菌33KDa脂蛋白是PB患者IL-12p40的有效诱导剂,外源性IFN-γ可上调IL-12p40分泌,为麻风病免疫治疗的建立提供了依据.     

RT-PCR检测16S rRNA基因片段对麻风菌活性的评价

目的:探讨麻风病患者皮损组织中麻风菌16S rRNA基因片段判断麻风菌活性的应用价值。方法:根据BI值和联合化疗(MDT)的疗期对27例麻风患者分组,以RT-PCR法检测皮损组织中麻风菌16S rRNA的特异性片段。结果:(1)无论BI高低,未经治疗的患者16S rRNA均为阳性。(2)MDT治疗、BI≥3～6者的11例患者中:有9例16SrRNA为阳性,MDT疗期小于和大于6个月的两组中均各有1例患者16S rRNA阴性。(3)MDT治疗、BI≤2的6例患者:有1例MDT小于6个月病人其16S rRNA阳性,其余5例患者16SrRNA均为阴性。结论:随MDT治疗的进行,麻风菌16S rRNA阳性患者比例减少;诊断时BI值越低的患者中,经治疗后皮损中麻风菌16S rRNA阴转的比例增大,提示麻风菌16S rRNA与患者皮损中麻风菌活性具有相关性。     

Studies on lepromin and soluble antigens of M.leprae: their classification standardization and use.

Before the discovery of armadillo as a susceptible animal the source of M.leprae was limited and hence the use of lepromin was not common in the field. In recent times, the soluble antigens of armadillo-derived M.leprae have been used extensively in the field. Although the results of the study show that these antigens do not differentiate always a susceptible form from the resistant form, they are able to segregate the polar forms of leprosy. In a given field situation the criteria for diagnosis is so stressed that leprosy is overdiagnosed and within one year of follow up nearly half the number of cases are noted as not leprosy. Hence, in such situations lepromin reaction would be definitely a poor correlate with the type of leprosy. However, in hospital based studies the lepromin reaction has always been and would remain useful in confirming the classification (Sengupta et al 1984). Lepromins and M.leprae soluble antigens have gone through extensive standardization procedures. As these antigens contain mostly common mycobacterial antigens along with the M.leprae-specific antigens, these antigens are unable to specifically diagnose M.leprae infection. After purification of M.leprae from infected armadillo tissue, it was expected that the soluble antigen of M.leprae would probably be as useful as tuberculin. However, this was not found to be true in case of lepromin. Specificity for M.leprae has been noted in the epitopes (antigenic sites) on cross reacting molecules (12 kd, 18 kd, 28 kd, 35 kd, 36 kd) of mycobacteria (Ivanyi et al 1983; Watson 1989). These specific epitopes, if synthesized, could be of use as skin test antigens for determining M.leprae infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Observations on nerve tissue infected with M. leprae

Nerve tissue from leprosy patients showed (i) small linear pinkish translucent crystalloid bodies, (ii) small round structures in relation to filamentous strands, (iii) short pieces of filaments with round spaces within them and (iv) miscellaneous structures like pink granules, brown bodies and dark masses. These structures are being studied for their relationship to leprosy.     

环戊利福霉素对麻风菌感染的实验治疗效果

本文报告以小鼠足垫模型比较RMP和R-77-3抗麻风菌感染的效果.每4周给药一次,R-77-3的ED5.剂量远低于RMP,用比例杀菌试验发现R-77-3对麻风菌的杀菌作用明显强于RMp.上述体内杭菌作用的显著差别主要由于R-77-3具有优异的药物动力学特性,T1/2比RMP长得多.提示R-77-3有可能比RMP更适合于麻风的间歇治疗.     

Influence of levamisole on lymphocytes and M. leprae in mice

Normal uninfected (N) and M. leprae infected mice (NI) were given levamisole in the dose of 2.5 mg/kg body weight. The animals were observed over a period of nine months for bacillary load, T and B cell counts and blast transformation with PHA. Significant increase in B cell counts was observed in the levamisole treated normal (NL) compared to normal control (N) group. T cell counts and blast transformation, however, remained unaffected. However, T-cell counts and blast transformation improved significantly in the infected and levamisole treated (NIL) as compared to the infected group (NI) not given levamisole. Bacillary loads remained unaltered in both, the infected (NI) and levamisole treated (NIL) group.     

Serum IgE reactivity to Malassezia furfur extract and recombinant M. furfur allergens in patients with atopic dermatitis

IgE reactivity to the opportunistic yeast Malassezia furfur can be found in patients with atopic dermatitis (AD). We have previously cloned and expressed 6 recombinant allergens (rMal f 1, rMal f 5-9) from M. furfur. In the present study, we used ImmunoCAP to investigate whether these rMal f allergens can be useful in the diagnosis of M. furfur-associated AD compared with the M. furfur extract. A total of 156 adult patients with a clinical diagnosis of AD participated in the study. Sixty-four percent had increased total serum IgE levels, 79% had specific IgE antibodies to common inhalant allergens and 47% had IgE antibodies to M. furfur extract. IgE antibodies to any of the rMal f allergens were detected among 86 (55%) of the patients, 14 (16%) of whom did not react to the M. furfur extract. Any individual rMal f allergen detected between 32% and 89% of the patients ImmunoCAP-positive to the M. furfur extract, with the highest sensitivity for rMal f 9. Therefore, a couple of individual rMal f allergens can improve the diagnosis of M. furfur-associated IgE allergies in patients with AD.     

Effect of diet on growth of M. leprae in mouse footpads

Semipurified diets, with equal amounts of vitamins, minerals and fibre, but varied in protein and fat content from pork, barbel fish or soya beans were tested for their possible effect on the growth of M. leprae in mouse footpads. 105 BALB/c male weanling mice were randomly divided into five diet groups of 21 mice each and fed for six months. Differences between bacterial counts of diet groups were found. The mouse foot pad model is suitable for dietary study in leprosy.     

云南省丘北县麻风菌株基因分型研究

目的:验证云南省丘北县麻风菌株与流行病学间的关联性。方法:对2003-2007年发现的106例新麻风患者菌株进行了6个VNTR位点分型,以系统发育树分析与流行病学的关联性。结果:丘北菌株依据(GTA)9等位基因型可分为两大菌群。第一枝由(GTA)9位点从9到13个重复数组成的A、B和C聚集株,主要分布在该县北部和西北部;第二枝由(GTA)9重复数高达20以上的D、E菌株组成,主要分布在中部和东南部。A至F聚集株内,至少有两个或以上有多个患者的家庭。第一菌群内患者间有明显的流行病学关联,但第二菌群内患者则缺乏关联性。结论:(GTA)9等位基因高度多态菌群来源与异质性的原因不清楚。以家庭和邻居关联的麻风病传播在丘北县很常见,有多个患者的家庭,感染菌株可能来自相同的传播链。     

Observations on the cultivation of M. leprae and M. tuberculosis in medium 'V' and 'V 1'.

Skin scrapings from five different active sites were collected from 14 leprosy patients and inoculated into medium V. Skin scrapings from three leprosy patients were inoculated into medium V 1. All the cultures were incubated at 8-10 degrees C. M. tuberculosis H37Rv, pretreatment isolates and streptomycin resistant strains were inoculated into medium V, with and without antibiotics, and incubated at 8-10 degrees C as well as 37 degrees C. Smears were made from the M. leprae and M. tuberculosis cultures at 0 hours and at different time points. The number of bacilli in the smears were counted. There was no increase in the number of M. leprae or M. tuberculosis in any of the cultures.