LETTERS TO THE EDITOR Female Sexual Dysfunction and Hormonal Status in Multiple Sclerosis

We read with great interest the article by Lombardi and colleagues exploring the correlation between hormonal status and sexual function in patients with multiple sclerosis (MS), a chronic autoimmune disorder in the central nervous system (CNS) [1]. Sexual dysfunction (SD) is associated with chronic diseases [2], and is more common in women suffering from MS than in the general she population [3]. Dysregulation of the hypothalamic–pituitary– gonadal axis has also been reported in MS [4]. Therefore, studies aiming to address the correlation between hormonal status and SD in female patients with MS are justified. Although notable percentages of blood hormonal alterations and sexual dysfunction were found in MS patients, no correlations between hormonal status and sexual function were found. The results are somewhat disappointing because a positive correlation between hormonal status and sexual function inMSmight promise the use of hormones as an intervention for SD in patients withMS. Besides, we have some concerns about the study design and data analysis. During the screening phase of the study, those who reported any pre-MS SD were ruled out [1]. Moreover, subjects with post-SD resulting from known causes other than MS should also be excluded. Because the residual disability levels of the enrolled subjects were from 2 to 6 according to the Kurtzke Extended Disability Status Scale, I am eager to know whether there is any correlation between MS severity and the Female Sexual Function Index (FSFI) or hormone levels. If yes, the disability levels may confound studies investigating the correlation between blood sexual hormones and SD measured by FSFI questionnaire. MS is primarily an autoimmune disorder in the CNS characterized by focal infiltration of immune cells including lymphocytes and macrophages, and subsequent immune-mediated demyelination [5]. At least four clinical subtypes of MS have been identified according to their clinical courses, including relapsing–remitting MS (RRMS), which accounts for more than four of five of all MS cases, secondary progressive MS, primary progressive MS, and progressive relapsing MS [6]. The clinical course of MS subtypes is illustrated in Figure 1. I wonder whether the authors performed stratified analysis as per the clinical subtypes of MS, e.g., RRMS vs. non-RRMS. The different stages at which the subjects were when enrolled may also influence the blood hormone levels.