Individual analysis of expected time on the waiting list for HLA-matched corneal grafts.

OBJECTIVE

Recent studies report the beneficial effect of HLA matching for long-term prognosis of penetrating keratoplasty (kp). This improvement of prognosis, however, has to be weighed against the additional time on the waiting list due to the search for a HLA-compatible graft. Reliable estimation of this additional waiting period is a prerequisite for informed consent on the waiting policy.

METHODS

A mathematical model based on survival analysis and HLA haplotype frequencies was used to estimate time on the waiting list for each of 1,400 HLA-typed patients registered at the Lions Cornea Bank NRW. Additionally, the waiting period of each patient was retrospectively determined. Both values were tested for correlation. This analysis was performed for acceptance of up to two mismatches on HLA-A, -B and -DR.

RESULTS

When accepting two, one and zero mismatches, median predicted waiting period was 1 +/- 6, 7 +/- 49 and 17 +/- 159 months respectively. Median waiting period in retrospective simulation was 1 +/- 3, 5 +/- 9 and 15 +/- 14 months. Correlation of values from the predictive formula and simulation was statistically significant (p < 0.0001).

CONCLUSION

Predicted time on the waiting list is a valuable tool for management of HLA matching in kp.