Enhancement in the histological diagnosis of leprosy in patients with only sensory loss by demonstration of mycobacterial antigens using Anti-BCG polyclonal antibodies

This study was undertaken to assess whether the immunoperoxidase technique using anti-BCG serum is able to confirm the diagnosis of early leprosy among patients whose unique clinical manifestation is a localized area of sensory loss, in a higher proportion than the routine mycobacterial staining methods, namely hematoxylin-eosin and Wade. The study was held in the north of a hyper-endemic area of leprosy, Manaus, Amazonas (Brazil). Fifty-one paraffin-embedded skin biopsy blocks were retrieved and processed for the immunohistochemical study, by means of anti-BCG polyclonal antibodies for the detection of mycobacterial antigens. The routine stains confirmed the leprosy diagnosis in 17% of the cases, while the immunostaining method confirmed it in 47%. The McNemar test showed that the observed difference between these two techniques was statistically significant (p = < 0.05). In the same way, 50 blocks of skin conditions considered in the differential histopathological diagnosis of early leprosy were processed for the immunohistochemical test to analyze the possibility of false-positive results which occurred in 8 (16%) patients. The study suggests that immunostaining may increase the proportion of the routine histological diagnosis of leprosy in patients who have sensory loss only, even while using biopsies obtained in fieldwork conditions. This is very advantageous in hyper-endemic areas and in areas that are in the post-elimination period of leprosy control where sensory loss may be a sentinel sign of the disease.

Distinct histopathological patterns in single lesion leprosy patients treated with single dose therapy (ROM) in the Brazilian Multicentric study

This paper aims to describe the histomorphologic features of skin biopsies of single lesion leprosy patients recruited at outpatient clinics in four Brazilian states in the Northeast (Amazonas and Rondonia), Southeast (Rio de Janeiro) and Center-West (Goiás) between October 1997 and December 1998. Patients clinically diagnosed as single skin lesion paucibacillary (SSL-PB) leprosy had a standard 4-mm punch biopsy taken from the lesion before rifampin, ofloxacin, minocycline (ROM) therapy. The features of the cellular inflammatory infiltrates, the presence of nerve involvement and acid-fast bacilli (AFB) were used to categorize SSL-PB biopsies into different histopathological groups. Two-hundred-seventy-eight (93.0%) out of 299 patients had a skin biopsy available. Seven single lesion patients were diagnosed as BL or LL leprosy types (MB) by the histopathological exams and 12 cases were excluded due to other skin diseases. Therefore, 259 patients had skin lesions with histomorphological features compatible with PB leprosy categorized as follows: 33.6% (N = 87) of the biopsies represented well-circumscribed epithelioid cell granuloma (Group 1); 21.6% (N = 56) less-circumscribed epithelioid cell granuloma (Group 2); 12.0% (N = 31) were described as mononuclear inflammatory infiltrate permeated with epithelioid cells (Group 3), and 29.7% (N = 77) had perivascular/periadnexal mononuclear inflammatory infiltrate (Group 4). Minimal/no morphological alteration in the skin was detected in only 8 (3.1%) SSL-PB patients categorized as Group 5, who were considered to have leprosy by clinical parameters. SSL-PB leprosy patients recruited in a multicentric study presented histomorphology readings comprising the whole PB leprosy spectrum but also a few MB cases. These results indicate heterogeneity among SSL-PB patients, with a predominance of well-circumscribed and less-circumscribed epithelioid cell granulomas (Groups 1 and 2) in the sites studied and the heterogeneity of local cellular immune response.

Histological observations on Montenegro's reaction in man

Foi realizado o estudo histológico do material obtido nas biópsias do local de inoculaçäo do antígeno para teste de Montenegro (T.M.) nos seguintes grupos de indivíduos: I) Seis pacientes com leismaniose cutânea comprovados parasitologicamente, com Montenegro positivo; II) Cinco indivíduos normias, näo residentes em zona endêmica, com Montenegro negativo; III) Nove soldados participantes de ensaios clínicos com vacina anti-LTA - MAYRINK e cols. 1979 e que tiveram o TM positivo 35 dias após vacinaçäo. IV) Um último grupo constituído de quatro soldados, também participantes de ensaio clínico com a mesma vacina acima, dois vacinados que näo mostraram TM positivo 35 días após vacinaçäo dois que receberam placebo. As biópsias foram realizadas 48 horas após a inoculaçäo do antígeno. O material foi fixado em formol à 10% (pH 7.2). Histologicamente, excetivando o grupo II (controle negativo), os grupos I-III-IV mostraram diferenças quantitativas no infiltrado mononuclear. Os quadros histológicos de cada grupo säo descritos e discutidos