Fetal microchimerism is not involved in the pathogenesis of lichen sclerosus of the vulva.

OBJECTIVES: The aim of this study was to investigate a possible relationship between fetal cell microchimerism and lichen sclerosus of the vulva. We searched for the presence of male cells and DNA in vulval tissue samples. METHODS: Paraffin-embedded skin biopsy samples from 15 women affected with vulval lichen sclerosus who gave birth to at least one son were analyzed for the presence of microchimeric male cells using fluorescence in situ hybridization (FISH) and fluorescent PCR. We included three lichen sclerosus samples originating from women without male offspring, six vulval specimens without pathological finding originating from autopsies and seven male gingival specimens as controls. RESULTS: Nucleated cells containing Y-chromosome specific sequences were neither detected at any site of the lesions nor in normal vulval specimens by using FISH. These results were confirmed by the use of PCR amplification demonstrating only DNA sequences specific for the X chromosome. No female microchimerism was detected in the male gingival samples. CONCLUSION: Despite the limited number and size of the samples, we conclude that persistent male fetal cells are not involved in the pathogenesis of lichen sclerosus of the vulva, since we consistently could not detect Y-chromosome specific sequences by using two molecular techniques.

Detection of maternal deoxyribonucleic acid in umbilical cord plasma by using fluorescent polymerase chain reaction amplification of short tandem repeat sequences.

OBJECTIVE: Umbilical cord blood is a source of hematopoietic stem cells for transplantation. Although the first clinical applications have been encouraging, concern has been raised about contamination of umbilical blood by maternal cells, which might constitute a theoretical risk of graft-versus-host disease. The aim of this study was to assess the frequency of maternal deoxyribonucleic acid (DNA) contamination in umbilical cord plasma by using fluorescent polymerase chain reaction amplification of highly polymorphic short tandem repeat DNA markers. STUDY DESIGN: Fifty-seven mother/child pairs were tested for the presence of maternal DNA sequences in cord plasma. After delivery, cord blood samples were collected via gravity. Maternal specific alleles were detected by using polymerase chain reaction amplification of 9 highly polymorphic short tandem repeat markers (D21S11, D21S1411, D21S1412, D18S386, D18S535, MBP-A, MBP-B, D13S631, and D13S634). RESULTS: All 57 mother-child pairs were informative for the identification of uniquely maternal alleles in at least 2 of 9 different short tandem repeat markers used per case. Uniquely maternal DNA sequences were found in 43 of 57 (75%) cord plasma samples. CONCLUSION: The results of our study demonstrate that maternal DNA is present in the majority of umbilical cord blood plasma samples. The technique described herein might have application in the screening of umbilical cord blood samples for the presence of contaminating maternal genetic material.