Detection of parvovirus B19 infection in formalin-fixed and paraffin-embedded placenta and fetal tissues.
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.
Quemelo
Paulo Roberto Veiga
PR
Department of Pathology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil. pquemelo@hotmail.com
Lima
Danielle Malta
DM
da Fonseca
Benedito Antônio Lopes
BA
Peres
Luiz Cesar
LC
D000914:Antibodies, Viral / Q000032:analysis; D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D005260:Female; D005333:Fetus / Q000473:pathology / Q000821:virology*; D006416:Hematoxylin; D006801:Humans; D015160:Hydrops Fetalis / Q000473:pathology / Q000821:virology*; D007150:Immunohistochemistry; D008297:Male; D016612:Paraffin Embedding; D010322:Parvoviridae Infections / Q000196:embryology* / Q000473:pathology; D016732:Parvovirus B19, Human / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D010920:Placenta / Q000473:pathology / Q000821:virology*; D016133:Polymerase Chain Reaction; D011247:Pregnancy
D000914:Antibodies, Viral; D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin