The Relationship between Mortality of Lung Transplant Recipients and Serum Cyclosporine Levels: Joint Modeling of Time-to-Event Data and Longitudinal Data

BACKGROUND

Lung transplantation (LTx) is a well-accepted treatment that can prolong survival of patients with advanced lung disease.

OBJECTIVE

To evaluate the association between serum cyclosporine level (SCL) pattern and mortality of LTx recipients.

METHODS

This retrospective cohort study included 1019 observations on 38 patients who underwent LTx in Masih Daneshvari Hospital from 2000 to 2013. The analysis applied a joint model with shared random effects.

RESULTS

The mean±SD age of the recipients was 36±14.5 years. The findings indicated that sex, age, body mass index (BMI), the underlying disease, and cytomegalovirus infection were not associated with mortality. The mortality risk for the recipients with acute rejection (AR) history was 1.54 times that of the recipients who had none (95% CI: 1.08-2.19). The association parameter in the joint model (α = 0.8) showed that higher SCL was associated with lower mortality risk (95% CI: 1-1.011). A slightly linear decreasing trend in SCL mean was found after 10 months post-LTx; a significant 2% per month (95% CI: -0.03 to -0.019).

CONCLUSION

AR history was found to be a risk factor in mortality in Iranian LTx recipients. Given the association between the higher SCL and lower mortality found in this study, it is recommended to pay serious attention to SCL changes in the overall post-transplantation survival assessment in Iranian LTx recipients.

The effect of withholding gonadotropin (a coasting period) on the outcome of in vitro fertilization cycles

OBJECTIVE

The purpose of this study was to evaluate the effects of coasting (withdrawing gonadotropin administration) on the cycle outcomes, including total number and quality of oocytes and embryos and pregnancy rate in patients undergoing in vitro fertilization.

STUDY DESIGN

Sixty-seven patients undergoing coasting were evaluated in a retrospective study at the Royan Institute between May 2002 and June 2003. All patients underwent standard long protocol with gonadotropin-releasing hormone (GnRH) analogue and human menopausal gonadotropin (HMG) and then in vitro fertilization and embryo transfer (IVF-ET). Coasting was considered when the estradiol level was more than 3000 pg/ml and the number of follicles >10 in each ovary. HCG was administered whenever estradiol reached < or =3000 pg/ml and then the (IVF-ET) program was carried out. According to coasting periods, patients were divided into two groups: coasting period < or =3 days and coasting period >3 days. Statistical comparisons were performed using Student's t test and Fisher's exact test.

RESULTS

There were no significant differences between the two groups with regard to mean age, body mass index (BMI), number of polycystic ovary syndrome (PCOS) patients, number of HMG ampoules and stimulation duration. The total number of retrieved oocytes decreased significantly in patients with more than 3 days of coasting (P=0.04). The number of high quality oocytes also decreased in this group; however, this did not reach significant levels. There were no significant differences between the two groups with regard to fertilization and pregnancy rate. None of the patients developed severe ovarian hyperstimulation syndrome (OHSS).

CONCLUSION

This study reveals that a long coasting period (>3 days) has a negative effect on the number of oocytes, although the fertilization and pregnancy rates are not affected. Prospective randomized studies with larger sample sizes are needed to compare coasting with other procedures.