Preeclamptic patient-derived circulating cell-free DNA activates the production of inflammatory cytokines via toll-like receptor 9 signalling in the human placenta.

OBJECTIVES: Preeclampsia, a pregnancy-specific syndrome, is associated with maternal systemic and placental inflammatory responses. Cell-free DNA (cfDNA) and cf-foetal DNA (cffDNA) in the blood are elevated in patients with preeclampsia and act as danger signals. Placenta-derived foetal DNA induces inflammatory responses and pregnancy complications in mice. However, whether extracellular DNA from the placenta really causes inflammatory responses remains unclear. Therefore, we investigated the effect of serum cfDNA and placental cffDNA on inflammatory responses using normal pregnant women and preeclampsia patients. METHODS: Sera were taken from normal pregnant women and preeclampsia patients, and human trophoblast cell line Sw.71 cells were treated with serum with or without toll-like receptor 9 (TLR9; a sensor of exogenous DNA) inhibitor and genome elimination reagent. For cffDNA collection, placental tissue from the participants was cultured, and the released cffDNA was administrated to Sw.71 cells. RESULTS: The amount of serum cfDNA was higher in preeclampsia patients than in normal pregnant women. Treatment of preeclampsia serum stimulated inflammatory cytokine secretion, which was inhibited by a genome elimination reagent. Expression levels of TLR9 and amount of cffDNA from the placenta were higher in preeclampsia patients than of normal pregnant women. Preeclampsia-derived cffDNA increased inflammatory cytokine levels compared with normal pregnant derived cffDNA. CONCLUSION: In human trophoblast cells, preeclampsia patient-derived cfDNA increased inflammatory cytokine levels via TLR9. Preeclampsia placenta released more cffDNA, which stimulated inflammatory cytokine. We suggest that elevated circulating cfDNA and cffDNA induces placental inflammatory responses, resulting in accelerated pathological features of preeclampsia.

Limited sampling strategy for the estimation of mycophenolic acid area under the concentration-time curve treated in Japanese living-related renal transplant recipients with concomitant extended-release tacrolimus.

Mycophenolate mofetil (MMF) is used for oral administration to prevent rejection in renal transplant recipients, and is rapidly converted into mycophenolic acid (MPA), the active metabolite, by hydrolysis in vivo. The area under the concentration-time curve (AUC(0-12 h)) of MPA is considered to be an effective pharmacokinetics parameter for predicting acute rejection. However, frequent blood sampling is required to calculate AUC(0-12 h), which imposes a burden on patients and providers. Therefore, we examined a limited sampling strategy (LSS) for estimation of MPA-AUC(0-12 h) using only a trough level (C0) and two points including C0 in Japanese living-related renal transplant recipients with concomitant extended-release tacrolimus (ER-TAC). The present study suggests that better estimation of MPA-AUC(0-12 h) can be obtained by using two points including C0 as compared with only C0 regardless of transplant progress. Furthermore, blood collection points showing the highest estimation of MPA-AUC(0-12 h) by adding to C0 were C4 at pre-transplantation (Tx) and 1 month post-Tx, and C6 at 3 months post-Tx. We conjecture that changes in renal function and serum albumin (Alb) accompanying transplant progress are aggravating factors in terms of estimation, because there was also a significant difference in the reciprocal of serum creatinine (1/Scr) and Alb between pre-Tx and post-Tx in this study. In conclusion, the present study provides useful information for effective and efficient monitoring of MPA levels in Japanese living-related renal transplant recipients.

Erythroid recovery affects tacrolimus levels after engraftment during stem cell transplantation.

Tacrolimus is commonly used in stem-cell transplants (SCT) for prophylaxis of graft-versus-host disease and is continuously administered throughout transplantation. The dose of tacrolimus is frequently decreased to maintain a desired concentration during the recovery of hemocytes after engraftment. If parameters which affect tacrolimus clearance are identified, it is of clinical use to estimate concentrations and aid dosing. The objective of this study was to identify which hematologic parameters affect tacrolimus clearance. Seventeen consecutive Japanese patients with hematological malignancies who received allogeneic SCT between March 2004 and January 2007 were enrolled in this study. Their steady-state concentrations were routinely measured and standardized as the concentration/dose (C/D) ratio ((ng/mL)/(mg/kg/d)). Multivariate analysis was performed to identify which hemocyte parameters affected the C/D ratio. Of the 13 patients, gradual dose reduction was required to combat elevated tacrolimus concentrations. The mean post-engraftment C/D ratio was higher than the pre-engraftment C/D ratio in each patient. The mean C/D ratio for all patients after engraftment was 1.56-fold higher (p=0.00004, range: 1.04-3.03) than that before engraftment. The variation ratio was calculated by dividing the C/D ratio by that on the engraftment day. Multivariate analysis revealed that the reticulocyte (RET) level (×10(3) count/µL) was the sole parameter influencing this ratio, and both parameters were expressed as: Variation ratio=0.004×RET+1.0. RET recovery of patients could influence the C/D ratio and tacrolimus clearance was affected by recipient original red blood cells, but not that of transfused red blood cells.