Tubal cytokine changes accompany the epithelial atypia of letrozole-stimulated ovaries

An increased proliferative activity, Ki67 immunoexpression and abnormal invaginations were observed in the OSE of LTZ6 group accompanied with occasional pseudostratification and loss of cilia of TEC. These changes became more pronounced in the LTZ12 where micropapillae, hyperchromasia, frequent deep invaginations, cysts of OSE as well as papillae and multilayering of TEC were noticed. The tubal level of IL-1β, IL-6, TNF-α and serum MCP-1 progressively increased in LTZ6 and LTZ12 groups compared with the control group. The significant positive correlation observed between these cytokines in the LTZ6 group became stronger in the LTZ12 one. However, no significant changes in the tubal IL-10 and TGF-β were detected. Therefore, further studies are required to consider these cytokines as objective markers to precisely assess severity of the associated epithelial changes particularly in long periods of stimulation.