I read with great interest the recent article by Doria et al (1) and, similar to others (2), was intrigued by the finding of extraordinarily low serum concentrations of estrogen, progesterone, and testosterone in systemic lupus erythematosus (SLE) patients during pregnancy, compared with those in normal parturients. However, I was even more surprised to find out that even in their healthy control gestations, the authors report almost unbelievably low estradiol concentrations (1). The reported 17β–estradiol concentrations in the study by Doria et al (1) ranged from 20 to 100 pg/ml, whereas the normal estradiol concentrations are 5–20 ng/ml (5,000–20,000 pg/ml) (3). Moreover, the reported pregestational estradiol levels as reported by Doria et al (page 206 in their article) are 0.11–0.07 pg/ml in SLE patients and healthy controls, whereas the normal physiologic estradiol concentrations are in the range of 30–350 pg/ml in the normal ovulatory woman. Is the explanation for the three-fold difference a mere typographical error? I assume all the estradiol concentrations were erroneously reported as pg/ml instead of ng/ml. If not, the huge difference needs a thorough explanation.
To the Editor:
Zeev Blumenfeld MD*, * Rambam Medical Center and Technion-Israel, Institute of Technology, Haifa, Israel