Human papillomavirus in foetal and maternal tissues from miscarriage cases.

Early miscarriage is still a concern, and viral infections are recognised as one of the causes of this adverse outcome. The causal relationship between HPV and miscarriage remains controversial. The aim of the study was to evaluate whether HPV infection indeed may occur in both the maternal and placental tissue in cases of miscarriage. Decidual and chorionic villi fragments (n = 118) were dissected from 81 miscarriage cases, 68 spontaneous and 13 intentional. HPV DNA was detected using the consensus primers MY09/11; in eight cases (9.9%, 8/81), seven of which (10.3%) were from spontaneous miscarriages and one (7.7%), was from an intentional miscarriage. The deciduas (4/8) and chorionic villi (5/8) were both infected with HPV. A reverse line blot was used to genotype HPV positive samples and revealed HPV6, 11, 58, 66 and 82. Although the results obtained cannot infer an association between HPV and pregnancy loss, it cannot be ruled out. Impact Statement What is already known on this subject? Miscarriages are considered to be the most common complication in pregnancy. Several possible causes of miscarriage have been considered, and the role of infections as one of those is confirmed, especially during the second trimester of pregnancy. The prevalence of HPV in conception products is still questionable. However, an HPV infection should not be ignored and its association with miscarriage must be considered. What the results of this study add? The present study reveals the presence of HPV in the foetal and maternal tissues of conception. What the implications are of these findings for clinical practice and/or further research? This issue deserves further investigation aiming to clarify the role of HPV in miscarriage cases; which are mainly related to the specific type and grade of tissues' abnormalities found co-topographically with a virus presence.

Molecular detection of adeno-associated virus in cases of spontaneous and intentional human abortion.

Pregnancy failure is a common event and often of unknown cause. Some viruses are thought to cause abortions including the adeno-associated viruses (AAV), viruses which are regarded as being without any definitive association to any human disease. This study investigated AAV infection in 81 human abortions, both spontaneous and intentional that occurred up to the 23rd week of gestation. Nucleic acid of AAV-2, 3, and 5 types from 118 decidual and chorionic tissues, collected from the patients in this study, was amplified by nested-PCR. In situ hybridization (ISH) was developed with a digoxigenin-labeled AAV probe in paraffin embedded tissues from the AAV positive cases. AAV was observed in 28.4% (23/81) of the cases, of which, 78.3% (18/23) were in the decidua and 21.7% (5/23) in the extravillous trophoblast, the chorionic plate, or chorionic villi fragments. AAV-2, the only type detected, occurred in 32.3% (22/68) and in 7.7% (1/13) of the spontaneous and intentional abortions, respectively. ISH revealed AAV in the decidua, chorionic tissue or chorionic plate and extravillous trophoblast. The detection of only AAV-2 type indicates that it is the most frequent in the population studied and/or shows tissue tropism. The presence of AAV in decidual or trophoblastic cells in cases of abortion, as observed by ISH, implies that the virus could jeopardize the pregnancy. The significant predominance in spontaneous cases suggests possibly a causal association between AAV and abortion.