Microquimerismo en dermtología / Microchimerism in dermatology

Se denomina microquimerismo a la presencia en un organismo de una pequeña población de células o ADN que proviene de otro individuo genéticamente diferente. La causa más común de microquimerismo adquirido en forma natural es el tráfico bidireccional de células que se produce durante el embarazo entre la madre y el feto. Puede tener efectos benéficos o nocivospara el huésped, dependiendo de múltiples factores. Ha sido implicado en la patogenia de enfermedades autoinmunes como la esclerodermia, el lupus eritematoso sistémico, el lupusneonatal y la dermatomiositis, en la reparación de tejidos y el cáncer...

Blood Chimerism in a Dizygotic Dichorionic Pregnancy / 대한진단검사의학회지

Blood chimerism in twins is known to occur through the transfer of hematopoietic stem cells between the fetuses via a common placenta. We present a case of blood chimerism in a dizygotic dichorionic twin pregnancy. The female twin was delivered at 34 weeks of gestation, and the male twin was stillborn. Pathologic examination confirmed dichorionic diamniotic placentas. The karyotype of the female child was obtained using peripheral blood sample, and it revealed a mixture of 46,XX and 46,XY cells (chi 46,XY[13]/46,XX[7]). FISH analysis performed on the buccal cells by using CEP X/Y probe (Abbott Molecular Inc., USA) revealed 100% XX signals (nuc ish Xcen(DXZ1x2)[500]). Gross examination of the external genitalia and abdominal ultrasonography revealed no definitive abnormal findings in relation to sex differentiation. When XX/XY chimerism is present in blood lymphocytes, careful examination of external genitalia and reproductive organs and further studies are required to detect chimerism in non-hematopoetic tissues. This is a rare case of blood chimerism in dichorionic placentas, in contrast to those in monochorionic placentas.