Pretransplantation fetal-maternal microchimerism in pediatric liver transplantation from mother

AIM To investigate the rates of pretransplantation fetalmaternal microchimerism(MC) and its effect on rejection in children receiving maternal liver grafts. METHODS DNA or blood samples before liver transplantation(LT) were available in 45 pediatric patients and their mothers. The presence of pretransplantation MC to non-inherited maternal antigens(NIMAs)(NIMA-MC) in the peripheral blood was tested using nested PCRsingle-strand conformation polymorphism analysis for the human leukocyte antigen(HLA)-DRB1 alleles. NIMA-MC was successfully evaluated in 26 of the 45 children. Among these 45 pediatric LT recipients,23 children(51.1%) received transplants from maternal donors and the other 22 from non-maternal donors.RESULTS Among these 26 children,pretransplantation NIMAMC was detected in 23.1%(n = 6),6.1(range,0.8-14) years after birth. Among the children with a maternal donor,the rate of biopsy-proven cellular rejection(BPCR) was 0% in patients with NIMA-MC positivity(0/3) and those with HLA-DR identity with the mother(0/4),but it was 50% in those with NIMA-MC negativity(5/10). Patients with NIMA-MC positivity or HLA-DR identity with the mother showed significantly lower BPCR rate compared with NIMA-MC-negative patients(0% vs 50%,P = 0.04). NIMA-MC-positive patients tended to show lower BPCR rate compared with NIMAMC-negative patients(P = 0.23). CONCLUSION The presence of pretransplantation NIMA-MC or HLADR identity with the mother could be associated with BPCR-free survival in pediatric recipients of LT from maternal donors.

Formation of microchimerism in rat small bowel transplantation by spienocyte infusion

AIM： To investigate the effect of donor splenocyte infusion combined with cyclosporine A （CsA） on rejection of rat small bowel transplantation （SBT）. METHODS： Male Sprague-Dawley （SD） rats and female Wistar rats weighing 230-270 g were used as donors and recipients respectively in the study. Heterotopic small bowel transplantation was performed. The rats were divided into three groups： group one receiving allotransplantation （SD→Wistar）, group two receiving allotransplantation （SD→Wistar） ＋ donor splenocyte infusion, group three receiving allotransplantation （SD →Wistar） ＋ donor splenocyte infusion ＋ CsA followed by CsA 10 mg/kg per day after transplantation, in which recipient Wistar rats were injected with 2 ×10^8 SD splenocytes 28 d before transplantation, and treated with CsA after transplantation. Finally, the specific DNA fragment of donor Y chromosome was detected in recipient peripheral blood and skin by PCR. The survival time after small bowel transplantation was observed. Gross and histopathological examinations were performed. RESULTS： The survival time after small bowel transplantation was 7.1 ± 1.2 d in group 1, 18.4 ± 3.6 d in group 2 and 31.5± 3.1 d in group 3. The survival time was significant longer （P 〈 0.01） in group 3 than in groups 1 and 2. The gross and histopathological examination showed that the rejection degree in group 3 was lower than that in groups 1 and 2.CONCLUSION： Donor splenocyte infusion combined with CsA decreases remarkably the rejection and prolongs the survival time after rat small bowel transplantation.

Presence of donor-and-recipient-derived DNA microchimerism in the cell-free blood samples of renal transplantation recipients associates with the acceptance of transplanted kidneys

Aim:To examine whether the existence of the donor-and recipient-derived DNA chimerism in recipient's plasma can be a predictive marker for the status of transplanted organ.Methods:One hundred and twenty-six female patients who had been transplanted with male kidneys were enrolled in the present study.In these female recipients,the SRY_Ⅰ, DYZ_I^(Ⅰst)and DYZ_Ⅰ^(2nd)genes on the Y chromosome from the plasma were prospectively examined using reverse tran- scription polymerase chain reaction(RT-PCR).Results:SRY,DYZ_Ⅰ^(Ⅰst)and DYZ_Ⅰ^(2nd)sequences were detected in the cell-free blood(plasma)of 97(77%)of 126 female patients with male kidney.The average time that the transplanted kidneys functioned was 8.7 years and 5.4 years among microchimerism-positive and microchimerism-negative recipients,respectively.The frequency of the patients who had acute rejection after renal transplantation was ap- proximately 10% and 28% in microchimerism-positive and microchimerism-negative recipients,respectively.Serum creatinine levels in microchimerism-positive patients were significantly lower than those in microchimerism-negative patients.Conclusion:These results suggest that plasma DNA microchimerism present in certain patients following renal transplantation and measurement of plasma DNA microchimerism using quantitative RT-PCR might be a useful predictor for the acceptance of transplanted kidneys.(Asian J Androl 2006 Jul;8:477-482)

Microchimerism in recurrent miscarriage

Maternal-fetal cell exchange during pregnancy results in acquisition of microchimerism, which can durably persist in both recipients. Naturally acquired microchimerism may impact maternal-fetal interaction in pregnancy. We conducted studies to ask whether microchimerism that a woman acquired from her own mother is detectable before or during pregnancy in women with recurrent miscarriage. Fetal microchimerism was also assayed. Women with primary idiopathic recurrent miscarriage （n=23） and controls （n=31） were studied. Genotyping was conducted for probands, their mothers and the fetus, a non-shared polymorphism identified and quantitative polymerase chain reaction performed to measure microchimerismin peripheral blood mononuclear cells. Preconception comparisons were made between recurrent miscarriage subjects and controls, using logistic regression and Wilcoxon rank sum. Longitudinal microchimerism in subsequent pregnancies of recurrent miscarriage subjects was described. There was a trend toward lower preconception detection of microchimerism in recurrent miscarriage versus controls, 6% vs. 19% （1/16 vs. 6/31, P=0.2）. During pregnancy, 3111 （27%） of recurrent miscarriage subjects who went on to have a birth had detection of microchimerism from their own mother, whereas neither of two subjects who went on to miscarry had detection （0/2）. This initial data suggest that microchimerism from a woman＇s own mother, while detectable in women with recurrent miscarriage, may differ from controls and according to subsequent pregnancy outcome. Further studies are needed to determine the cell types,quantities and any potential functional role of microchimerism in recurrent miscarriage.

Fetal cell microchimerism in the maternal mouse spinal cord

Fetal cell microchimerism refers to the persistence of fetal cells in the maternal tissues following pregnancy. It has been detected in peripheral organs and the brain, but its existence in the spinal cord has not been reported. Our aim was to detect fetal cell microchimerism in the spinal cord of maternal mice. C57BL/6 female mice were crossed with GFP transgenic male mice and sacrificed after their first or third delivery. GFP-positive cells, which were presumably from fetuses whose fathers were GFP transgenic, were detected in the spinal cord by fluorescence microscopy and immunohistochemistry. PCR was also performed to detect GFP DNA, which must come from GFP hemizygous fetuses. We found GFP-positive cells and detectable GFP DNA in most of the maternal spinal cords. Twenty percent （1/5） of the mice that were only pregnant once had detectable fetal cells, while 80% （4/5） of those that were pregnant three times had detectable fetal cells. Some fetal cells, which not only emitted green fluorescence but also expressed NeuN, were detected in the spinal cords from maternal mice. These results indicate that fetal cells migrate into the spinal cord of a maternal mouse during and/or after the gestational period, and the fetal cells may differentiate into neurons in the spinal cord.

Influence of obstetric factors on the development of postpartum antithyroid antibodies

Aim: To correlate obstetric data with the appearance of antithyroid antibodies. Methods: A 6 months follow up was performed on 135 healthy women with assessment of TSH, T3, T4 and antithyroid antibodies (anti thyroglobulin and anti peroxidase). Correlation of diverse obstetrical parameters with the appearance of antithyroid antibodies at 2 and 6 months postpartum was determined. Results: Only two parameters were significant during the complete follow up: the newborn weight, which correlated with both antibodies (anti-thyroglobulin and anti-peroxidase) positivity and the maternal height, which exclusively correlated with anti-thyroglobulin positivity. Conclusions: Correlation of maternal height and newborn weight with positive autoantibodies allows to consider a future clinical screening test for this disorder.