Mast Cell Activation Syndrome in COVID-19 and Female Reproductive Function: Theoretical Background vs. Accumulating Clinical Evidence

Figure 2

The potential sites of mast cell activation syndrome (MCAS) that may affect female reproductive function. There are indications to believe that SARS-CoV-2 infection and related COVID-19 may produce release of MC mediators from MC sources within female reproductive organs and other related to reproduction organs, such as 1: hypothalamus; 2: pituitary gland; 3: thyroid gland; 4: endometrial tissue outside the uterus (endometriotic foci); 5: peritoneal fluid; 6: uterus (endometrium, myometrium), 7: fallopian tube; 8: ovary; and 9: blastocyst, placenta, and decidua. Surprisingly, in majority of cases, histologic rationale for increased risk of MCAS (i.e., presence of mast cells in the respective organs) is not confirmed by pathophysiology (i.e., clearly proven relationship: MCAS⟶reproductive disorder), and so far, clinical data do not support that COVID-19 triggers MCAS in female reproductive system. See the main text (Section 4) for details.