Detection of parvovirus B19 infection in formalin-fixed and paraffin-embedded placenta and fetal tissues Detecção da infecção pelo parvovírus B19 em placenta e tecidos fetais fixados em formalina e embebidos em parafina

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Paulo Roberto Veiga Quemelo, Danielle Malta Lima, Benedito Antônio Lopes da Fonseca, Luiz Cesar Peres
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2007
• Subjects: Immunohistochemistry; Hydrops fetalis; Parvovirus B19; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1590/S0036-46652007000200007; https://doaj.org/article/6d87781811734da6b02b6d3a0a7aa25e

Parvovirus B19 infection was first discovered in 1975 and it is implicated in fetal death from hydrops fetalis the world over. Diagnosis is usually made through histological identification of the intranuclear inclusion in placenta and fetal organs. However, these cells may be scarce or uncharacteristic, making definitive diagnosis difficult. We analyzed histologically placentas and fetal organs from 34 cases of non-immune hydrops fetalis, stained with Hematoxylin and Eosin (HE) and submitted to immunohistochemistry and polymerase chain reaction (PCR). Of 34 tissue samples, two (5.9%) presented typical intranuclear inclusion in circulating normoblasts seen in Hematoxylin and Eosin stained sections, confirmed by immunohistochemistry and PCR. However, PCR of fetal organs was negative in one case in which the placenta PCR was positive. We concluded that parvovirus B19 infection frequency is similar to the literature and that immunohistochemistry was the best detection method. It is highly specific and sensitive, preserves the morphology and reveals a larger number of positive cells than does HE with the advantage of showing cytoplasmic and nuclear positivity, making it more reliable. Although PCR is more specific and sensitive in fresh or ideally fixed material it is not so in formalin-fixed paraffin-embedded tissues, frequently the only one available in such cases. O parvovírus B19 foi detectado em 1975 e desde sua descoberta tem se mostrado um agente infeccioso importante em seres humanos, cujo diagnóstico pode ser feito pelo exame histológico através do encontro de inclusão nuclear em tecidos fetais ou placentários. No entanto, estas células podem ser escassas ou não apresentarem características típicas, dificultando o diagnóstico. Analisamos placentas e órgãos fetais de 34 casos de hidropisia fetal não-imune corados com Hematoxilina e Eosina (HE) e submetidos à reação em cadeia da polimerase (PCR) e imuno-histoquímica (IH). Em dois casos (5,9%) houve positividade na placenta pelo HE, IH e PCR. No entanto, PCR ...