Immunogenetic study of parvovirus B19 infection and TNF alpha gene polymorphism in women with recurrent miscarriage

Abstract

Viral infections during pregnancy have been associated with adverse pregnancy outcomes and birth defects in the offspring. Viruses rarely cross the placental barrier, but when the virus does reach the fetus, it can result in severe birth defects such as microcephaly or even fetal death. Human parvovirus (B19) is thought to cause severe complications is spontaneous abortion. Normal pregnancy is related to the successful transition from type 1 cellular immunity to type 2 cellular immunity. TNFalpha, induced the production of type 2 cytokines. These experiments were conducted to study the effect of human B19 virus on the pregnant women and cause abortion. This case control study was done for 100 patients including different ages that range from 18-42 age that sever recurrent miscarriage. Also, the study includes 50 apparently healthy control (AHC) this age were similar with the patients age. They were collected from different general hospitals in Hilla; Baghdad as well as Mid-Euphrates Governorates of Iraq, during the period from February 2021 to September 2021. Endometrium; Cervical swabs; fetal fluids swabs as well as Blood specimens were collected and processed to extract viral genome and total DNA gene for screened human B19 virus by using PCR and TNF-α (rs 361625) polymorphism by PCR and sequencing. In addition, estimation serum TNF concentration by enzyme-linked Immunosorbent assay (ELISA). The obtained results of this study are summarized as follows:‎ The mean age of the patients with RPL was (32.70±12.41 years) was mor than the mean age of the apparently healthy control AHC (30.67 ± 11.17 years). There are non-significant statistical differences (p=0.47) between Abortion; RPL and AHC. A strong positive relationship (with highly significant correlation) was found between number of participants; number abortion; week of abortion and Maternal age (P< 0.001). However, there are no significant correlation between number of participants with control maternal age. In women with RPL, the most commonly affected age stratum infected with DNA – B19 was (30-39 years) which constituted 48% (12 out of 25 cases), while the age stratum (17-29 years) was constituted 32% (8 out of 25 cases), followed by 20% (5 out of 25) in age stratum (40 – 49 years).Statistical comparison of these B19 in the Patients with Women With RPL according to age stratum revealed significant differences (p< 0.05). The percentage of a single band (317 bp) of the target sequence of TNF-α -238G/A (rs361625) gene. The positive result, according to PCR amplification of a single band (317 bp) of TNF-α -238G/A (rs361625) gene in women patients with RPL and HC were 23.3% (35 of 150 cases) and 14% (7 of 50 cases), respectively. While the negative results were in women patients with RPL and AHC were 76.7% (115 of 150 cases) and 86% (43 of 50 cases), respectively. The mean of serum TNF-α concentration for AHC and women patients with RPL groups were 6.25 ±0.78 pg./ml and 12.50 ±1.60 pg./ml,respectively. Statistically, significant difference (p<0.05) was found on comparing the mean of serum TNF-α concentration among these study groups.