Paper 39: Sex Mismatch Between Donor and Recipient is Associated with Decreased Graft Survivorship at 5-years After Osteochondral Allograft Transplantation

OBJECTIVES: Sex mismatch between donor and recipient has been considered a potential contributor to adverse outcomes following solid organ transplantation. However, the influence of sex mismatching in osteochondral allograft (OCA) transplantation is yet to be determined. Therefore, the objective of this study was to evaluate whether donor-recipient sex mismatching impacts graft survival after OCA transplantation. METHODS: In this review of prospectively collected data, patients who underwent OCA transplantation between November 2013 and November 2017 by a single surgeon were analyzed. Cumulative survival was performed through the Kaplan–Meier method using log-rank tests to compare patients with similar donor groups. Multivariable Cox regression analysis adjusted for patient age, graft size and body mass index (BMI) were used to evaluate the influence of donor–recipient sex on graft survival. RESULTS: A total of 154 patients were included, 102 (66.2%) who received OCAs from a same sex donor, and 52 (33.8%) from a different sex donor. At 5 years follow-up, a significantly lower graft survival rate was observed for different sex donor transplantation in comparison to same sex donor (63% versus 92%, p = 0.01). (Figure 1.) When correcting for age, graft size and BMI, donor-recipient sex mismatching demonstrated a 2.9 times greater likelihood to fail at 5 years compared to donor-recipient same sex (p = 0.03). A subgroup analysis showed no significant difference in graft survival between female-to-female and female-to-male groups (91% and 84%, respectively). (Figure 2.) Conversely, male-to-male demonstrated a significant higher cumulative 5-year survival (94%, p = 0.04), whereas a lower survival was found in the male-to-female group (64%, p = 0.04). Multivariable Cox regression indicated a 2.6 times higher likelihood of failure for male-to-female in comparison with other groups (p = 0.04). Male-to-male had a tendency toward decreased likelihood of OCA failure (0.33 hazard ratio), although without statistical significance. CONCLUSIONS: Mismatch between donor and recipient sex has a negative effect on OCA survival following transplantation, particularly in those cases when male donor tissue was transplanted into a female recipient.