Erythropoiesis and renal transplant pregnancy

Objective. To examine erythropoiesis in renal transplant pregnancies. Methods. Retrospective cohort study of 30 renal transplant cases and 30 age , smoking and parity-matched healthy controls with normal index pregnancy. Retrospective chart review and assay of frozen antenatal serum (for serum e rythropoietin concentration [serum EPO]), transferrin receptor protein [TfR ], ferritin, folate and B12) were performed. The linear regression equation for normal pregnancy controls was used to calculate predicted [serum EPO] and the observed/predicted (O/P) log [serum EPO] was plotted. The relations hip between [serum EPO] and haemoglobin (Hb) among transplant cases was con sidered to be different from that among controls if the slope of the O/P lo g [serum EPO] versus Hb regression was significantly different from zero. Results. The transplant (14 cadaveric) to conception interval was (median [ range]) 33.5 [4, 189] months. Immunosuppressants were azathioprine (n = 25) , cyclosporine (n = 22) and/or prednisone (n = 25). Cases were more often p rimiparous (20 vs. 7 [controls]; p = 0.01), had pro-existent hypertension ( 20 vs. 0 [controls]; p < 0.001), developed new/increased hypertension or pr e-eclampsia (28 vs. 0 [controls]; p < 0.001) and an antenatal rise in creat inine (14 vs. 2 [controls]; p < 0.001). In early pregnancy, cases had simil ar EPO (15.2 [2.6, 84.6] vs. 15.7 [6.4, 41.0] [controls] U/L) but lower Hb (101 [65, 129] vs, 116 [106, 150] g/L; p < 0.001). Twenty-two (73%) cases h ad Hb < 100 g/L (vs. 4 [controls]; p < 0.0001); Hb was comparable at 6 wk p ostpartum With advancing gestational age (GA), Hb remained stable and serum EPO increased in both groups. The slope of the O/P log [serum EPO] versus Hb for transplant cases was significantly different from zero within both t he 17-28 wk (slope +/- SEM: 0.010 +/- 0.002; p < 0.0001) and the 29-42 wk G A categories (0.006 +/- 0.003; p = 0.02). Cases showed smaller rises in ser um TfR (change 481 [-1471. 2780]) vs. 1119 [ - 698, 4195] [controls] ng/mL; p = 0.005). Conclusions. Anaemia frequently complicates renal transplant pregnancies, i n which serum EPO is inappropriately low and the rate of erythropoiesis blu nted.