Clinical value of biological activity of serum luteinizing hormone in patients with ovulatory failure.

Effects of LH-RH injection on the biological and immunological activities of LH were studied in patients with ovulatory failure. The LH-RH stimulation induced an abrupt increase in both biological and immunological activities of LH in both normal women and patients with ovulatory failure. The mean ratio of biological to immunological LH activities (B/I ratio) before LH-RH injection was 1.06 +/- 0.06 in the group of normal women, and was stable in each case for up to two hours after LH-RH injection. Patients with ovulatory failure could be divided into 2 subgroups on the basis of the B/I ratio of basal LH: one with a B/I ratio within the normal range (mean +/-2SD of B/I ratio in normal women) and one with a B/I ratio greater than the normal range. Patients with a normal B/I ratio had good responses to the clomiphene treatment, whereas those with a high B/I ratio showed poor responses to the same treatment. The basal levels of serum estradiol were significantly (p less than 0.05) lower in patients with a high B/I ratio than those with a normal B/I ratio. These results suggested that the determination of the B/I ratio would be a useful parameter in clinical care.