Evaluation of agreement between clinical and histopathological data for classifying leprosy.

BACKGROUND: The diversity of clinical manifestations of leprosy has given rise to different classification systems. However, there are important differences in the sensitivity and specificity of these classifications. The objective of this study was to evaluate the agreement between clinical and histopathological data for classifying leprosy. METHODS: A total of 1265 patient reports containing clinical and histopathological data relating to the diagnosis and classification of leprosy were included in this study. The diagnostic concordance between the clinical form (Madrid classification) and the histopathological type, as well as the initial and final classifications, was calculated by dividing the number of concordant cases by the total number of patients. RESULTS: The overall agreement between the World Health Organization operational classification and the results of direct smear examination of the lesion for acid-fast bacilli was 84.8% (1073/1265). The clinical-histopathological agreement was 58.1% (735/1265). The indeterminate and lepromatous forms were those that showed the highest percentages of agreement: 72.1% (186/258) and 71.0% (142/200), respectively. CONCLUSION: Although classifications based on clinical characteristics have an important role in the control of leprosy, they present flaws that can influence the adequacy of treatment. Therefore, a histopathological examination is important for appropriate treatment.

Multiplex PCR technique could be an alternative approach for early detection of leprosy among close contacts--a pilot study from India.

BACKGROUND: Implementation of Multi drug Therapy (MDT) regimen has resulted in the decline of the total number of leprosy cases in the world. Though the prevalence rate has been declining, the incidence rate remains more or less constant and high in South East Asian countries particularly in India, Nepal, Bangladesh, Pakistan and Srilanka. Leprosy, particularly that of multibacillary type spreads silently before it is clinically detected. An early detection and treatment would help to prevent transmission in the community. Multiplex PCR (M-PCR) technique appears to be promising towards early detection among contacts of leprosy cases. METHODS: A total of 234 paucibacillary (PB) and 205 multibacillary (MB) leprosy cases were studied in a community of an endemic area of Bankura district of West Bengal (Eastern India). They were assessed by smear examination for acid-fast bacilli (AFB) and M-PCR technique. These patients were treated with Multidrug Therapy (MDT) as prescribed by WHO following detection. A total of 110 MB and 72 PB contacts were studied by performing M-PCR in their nasal swab samples. RESULTS: 83.4% of MB patients were observed to be positive by smear examination for AFB and 89.2% by M-PCR. While 22.2% of PB patients were found to be positive by smear examination for AFB, 80.3% of these patients were positive by M-PCR. Among leprosy contacts (using M-PCR), 10.9% were found to be positive among MB contacts and 1.3% among PB contacts. Interestingly, two contacts of M-PCR positive MB cases developed leprosy during the period of two years follow up. CONCLUSION: The M-PCR technique appears to be an efficient tool for early detection of leprosy cases in community based contact tracing amongst close associates of PB and MB cases. Early contact tracing using a molecular biology tool can be of great help in curbing the incidence of leprosy further.

Prevention of leprosy using rifampicin as chemoprophylaxis

An intervention study was implemented on five Indinesian island highly endemic for leprosy to determine whether rifampicin can be used as chemoprophylaxis to prevent leprosy. The population was actively screened before the intervention and subsequently once a year for three years. In the control group, no chemoprophylaxis was given. In the contact group, chemoprophylaxis was only given to contacts of leprosy patients and in the blanket group to all aligible persons. The cohort consited of 3,965 persons. The yearly incidence rate in the control group was 39/10,000; the cumulative incidence after three years was significantly lower in the blanket group (P=0.031). No difference was found between the contact and the control groups (P=0.93). Whether this apparent reduced leprosy incidence in the first three years in the blanket group is due to a delayed development of leprosy or a complete clearence of infections needs to be determined

Fluorescent probes as tools to assess the receptor for the urokinase-type plasminogen activator on tumor cells.

Flow cytofluorometric protocols (FACScan) are described for the rapid and quantitative real-time analysis of binding of FITC-pro-u-PA to cell surface receptors (u-PAR) on living, resting, and also on PMA-stimulated human monocytic U937 cells. Binding of pro-u-PA was visualized by CLSM. This fairly new technique is superior over conventional fluorescence microscopy and is an alternative to electron microscopic approaches. Both flow cytofluorometry and confocal laser scanning microscopy allow the analysis quantitatively and with high-sensitivity binding of FITC-pro-u-PA to single suspended or adherent cells. By CLSM u-PA/u-PAR were found to be located in heterogeneously distributed discrete patches at the cell surface on U937 and not inside the cell. This is in agreement with previous studies by Hansen et al, who applied radioiodinated u-PA and electron microscopy to locate u-PAR on microvilli of fixed U937 cells. By flow cytofluorometry, it was possible to quantify the time-dependent and temperature-dependent binding of FITC-pro-u-PA to living single U937. Apparent saturation of u-PAR was achieved at 5 nM FITC-pro-u-PA for both nonstimulated and PMA-stimulated U937 cells. Half saturation of u-PAR was also determined. Nonstimulated U937 was 0.7 nM, and PMA-stimulated U937 was 1.1 nM of FITC-pro-u-PA. This increase in half-saturation concentration in PMA-stimulated cells is paralleled by a steep increase in binding sites (3.6-fold). The use of fluoresceinated reference beads is recommended to verify changes in affinity and binding sites. Using CLSM or flow cytofluorometry, it is also possible to study the structure relationship of u-PA/u-PAR in the presence of competitive binding analogues or inhibitors. Fluorescence techniques will also permit the identification of u-PAR-positive cells in blood, ascitic fluid, or biopsies obtained from cancer patients.

Simplificação da técnica de Perdrau

O autor desenvolveu uma técnica de impregnação pela prata a partir do método clássico de Perdrau com as seguintes vantagens, entre outras: 1) Economia de tempo, pois executa-se em 25 minutos; 2) Economia de material; 3)É aplicável a esfregaços; 4) Permite o uso de vários fixadores.