| Abstract |
Several factors have been implicated in the aetiology of spontaneous abortions (SA) and viral infections seems to have a causal role, although data are mainly epidemiological and rather controversial. A major problem in the study of viral infections, is the indirect assays of their detection, like the commonly used serological assays, which have disadvantages such as hyposensitivity and the appearance of cross reactions. Other assays are time - consuming (cell cultures) or have low sensitivity and specificity. Parvovirus - B19, herpes simplex virus (HSV) type 2 and cytomegalovirus (CMV) are implicated for adverse effects on the normal course and outcome of the pregnancy, but it has not been clarified whether they contribute to the aetiopathogenesis of spontaneous abortions. They are DNA viruses and are usually correlated with a variety of clinical conditions in the female population. The human papilloma virus (HPV) has not been associated with adverse effects on the pregnancy, however it is very often found in the cells of the lower genital tract of women. In this study we investigated whether or not, these common human viruses can be detected in curettage material from SA, by using the polymerase chain reaction technique (PCR). This technique has been employed to amplify targeted regions of genomic DNA several thousandfold, providing a specific, rapid and sensitive means of detecting viral genomes in clinical samples. We evaluated 102 cases of SA at less than twenty weeks gestation for the detection of Parvo-B19, HSV, CMV and HPV DNA. Serological assays were used for the detection of specific IgM and IgG antibodies against the above viruses except for HPV. We found parvo-B19 DNA in two cases of SA, where the clinical and serological data were indicative of an acute recent infection from the virus. In another eight cases, there were serological markers of activated parvo-B19 infection, however, the results of PCR amplification in the abortion material were negative. Herpes simplex virus type 2 was found in two cases and the type 1 in one case of SA. There were no obvious clinical manifestations indicating a current herpes infection and the serological markers showed a secondary infection in two cases and past infection in the other. However, there was a high rate of positive IgM antibodies against HSV-1 (17,6%) and HSV-2 (13,7%). We did not detect CMV and HPV genome in any case of SA, even in the four cases where IgM antibodies against CMV were present. Conclusively, the use of PCR technique in the detection of viruses directly in curettage material from SA, constitutes the more reliable and sensitive method for the investigation of their possible contribution to the early termination of a pregnancy. The PCR data from this study indicate that parvovirus B19 and HSV type 1 and 2 may have an abortional role, resulting in early SA in a small number of cases. On the other hand no clear evidence was found implicating CMV and HPV as abortional factors. Serological assays were not useful for the elucidation of the role of the viruses in inducing SA and no correlation between the PCR results and the serological markers was observed.
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