Dermatitis infectiva: una revisión: a propósito de una experiencia peruana / Infective dermatitis: a review: about Peruvian experience

La dermatitis infectiva es una enfermedad eccematosa crónica de la niñez, que siempre compromete el cuero cabelludo y puede progresar a leucemia/linfoma de células T o a paraparesia espástica tropical. Es una condición dermatológica especial que está relacionada a la infección por el retrovirus linfotrópico humano a células T de tipo 1 (HTVL-1). En la niñez la forma de trasmisión más importante es a través de la lactancia materna. La expresión clínica así como su progresión están relacionadas con la carga viral, condiciones inmunológicas del paciente (infestación por Strongiloides stercoralis) y la intensidad de la respuesta inflamatoria. En esta revisión se destacan las características clínicas de esta entidad y se resaltan además sus hallazgos histopatológicos.

Infective dermatitis is a chronic, eczematous dermatitis of childhood that always involves the scalp and may progress to adult T-cell leukemia/lymphoma or tropical spastic paraparesis. It is a special dermatologic condition that has been linked to human T-cell lymphotropic virus type 1 (HTLV-1) infection. The most important route of transmission is vertical through breast-feeding. The clinical expression as well as its progression is related to viral load, immune status of patients (infestation by Strongyloides stercoralis) and the intensity of the inflammatory response. This review highlights the clinical features of this entity and also emphasizes its histopathological findings.

Genetic mutation and early onset of T-cell leukemia in pediatric patients infected at birth with HTLV-I.

T-cell leukemia/lymphoma (T-c LL) associated with prior infection with HTLV-I is rarely described in children. We present herein, the clinical, morphological, and virologic features of T-c LL, which occurred in eight pediatric cases with similar features of ATLL described in adults. There were three girls and five boys with age ranging from 2 to 18 years. Lymphoadenopathy, hepatosplenomegaly and marked skin lesions were presented in all cases. Five patients had hypercalcemia. The diagnostic criteria of T-c LL were based on both morphological and immunophenotypical analyses characterized by T-cell markers positively. Seven cases were cCD3+, CD4/CD25+, whereas CD1a and TdT were negative in all cases tested. HTLV-I antibodies were detected in all cases. HTLV-I provirus integration of at least one provirus was seen in all cases tested by molecular analysis. Mother-to-child transmission of HTLV-I was demonstrated in six cases. Interestingly, a homozygous deletion in p16 gene locus was observed in all four cases studied, while exons 7 and 8 of p53 were deleted in one child. The deletion of the p16(INK4A)/p14(ARF) or mutation of p53, key regulatory protein of cell cycle checkpoint in G1/S progression, found in five of the eight pediatric patients suggests that in these cases genetic lesions associated with HTLV-I infection may predispose for an early onset of leukemia.

HTLV-I maternal transmission in Martinique, using serology and polymerase chain reaction.

We have investigated HTLV-I and HTLV-II infection in children born to HTLV-I-seropositive or indeterminate Western blot mothers in Martinique by using the polymerase chain reaction (PCR). Only HTLV-I and no HTLV-II-positive samples were found in this study. All the samples from HTLV-I-seropositive children and adults were PCR positive, whereas the four HIV-I-seropositive and Western blot HTLV-I-negative mothers and their eight children were all PCR negative. Therefore, PCR and serology were in complete agreement in these patients. However, two of the six mothers who were first indeterminate by Western blot, and who later became seronegative, were found positive by PCR. Of the 27 children (ages 2-12 years), born to HTLV-I-seropositive and PCR-positive mothers, 2 were seropositive and PCR positive, 5 were seronegative and PCR positive with 2 primer pairs in gag and pol, and 4 were seronegative and PCR positive with only 1 of the primer pairs. In contrast to an initial rate of transmission of 7% estimated by serology we found a rate of transmission of 28 to 41% (whether or not children who were positive with only one of the primer pairs were included). Thus, our study confirms that PCR is useful in detecting HTLV-I infection in children before seroconversion and underlines the potential lack of sensitivity of serology to detect contaminating HTLV-I blood units in endemic areas.

Detection of human T-cell lymphotropic virus type 1 infection by the polymerase chain reaction using dried blood specimens on filter papers.

A simple method for detection of proviral DNA sequences of human T-cell lymphotropic virus type 1 (HTLV-1) was developed using dried blood specimens on filter papers. The whole blood was blotted onto the Guthrie paper. After the blood has dried, the blotted paper was punched out into small discs. The discs were then boiled to prepare the template for PCR (filter paper-PCR method). The filter paper-PCR method detected even a single HTLV-1-infected cell in three discs. The sensitivity of the filter paper-PCR method was equivalent to that of the method in which DNA was extracted with phenol and used as the template for PCR (DNA extraction-PCR method). In addition, DNA in the blotted filter paper was still utilizable as the template after the storage at 25 degrees C for at least 7 wk. A total of 53 clinical specimens from 30 seropositive and 23 seronegative individuals who were screened by particle agglutination (PA) test were analysed for HTLV-1 DNA by both PCR methods. Of 30 PA-positive specimens, 28 were also positive for HTLV-1 antibody by Western blot (WB) analysis, but two were indeterminate. The twenty eight WB-positive and one of the two indeterminate specimens were positive for HTLV-1 proviral DNA by both PCR methods. Of 23 PA-negative specimens, 22 were negative for HTLV-1 proviral DNA by both PCR methods. However, one PA-negative specimen was positive by both PCR methods. This patient was a 16-mth-old infant who was born to an HTLV-1 carrier mother and fed thereafter without her breast milk. In comparison to DNA extraction-PCR method, the sensitivity and specificity of the filter paper-PCR method was 100%, respectively.

[Maternal-infant transmission of the HTLV-1 virus]. / Transmission mère-enfant du virus HTLV-1.

The virus is transmitted horizontally via the bloodstream or sexual intercourse but vertical transmission is also believed to be a major mode of contamination. Between 20 and 25% of children born to seropositive mothers are believed to be infected and more than 90% of mothers whose children are found to be seropositive are themselves infected. If transplacental route appears to be exceptional or poorly documented, transmission by breast-feeding has been proved by virological, experimental and epidemiological arguments and is a major mode of contamination.

Identification of HTLV-I sequence in cord blood mononuclear cells of neonates born to HTLV-I antigen/antibody-positive mothers by polymerase chain reaction.

We developed a polymerase chain reaction (PCR) method which has high sensitivity and simple technique in order to investigate the presence or absence of human T lymphotropic virus type I (HTLV-I) provirus in cord blood mononuclear cells of neonates born to HTLV-I carrier mothers. Out of 40, three subjects were found to contain the HTLV-I provirus genome. These three subjects remained HTLV-I sequence-positive in follow-up study. On the other hand, when examined by a conventional technique for detection of HTLV-I-associated antigen on peripheral mononuclear cells, all 40 neonates were HTLV-I-associated antigen-negative. These results suggest that PCR is more sensitive than the conventional antigen detection method and is useful in early detection of HTLV-I infection in neonates born to HTLV-I carriers.