The state of adolescent menstrual health in low- and middle-income countries and suggestions for future action and research

In recognition of the opportunity created by the increasing attention to menstrual health at global, regional, and national levels, the World Health Organization’s Department of Sexual and Reproductive Health and Research and the UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction convened a global research collaborative meeting on menstrual health in adolescents in August 2018. Experts considered nine domains of menstrual health (awareness and understanding; stigma, norms, and socio-cultural practices; menstrual products; water and sanitation; disposal; empathy and support; clinical care; integration with other programmes; and financing) and answered the following five questions: (1) What is the current situation? (2) What are the factors contributing to this situation? (3) What should the status of this domain of adolescent menstrual health be in 10 years? (4) What actions are needed to achieve these goals? (5) What research is needed to achieve these goals? This commentary summarizes the consensus reached in relation to these questions during the expert consultation. In doing so, it describes the state of adolescent menstrual health in low- and middle-income countries and sets out suggestions for action and research that could contribute to meeting the holistic menstrual health needs of adolescent girls and others who menstruate worldwide

Natural Killer (NK) Cells in Antibacterial Innate Immunity: Angels or Devils?

Natural killer (NK) cells were first described as immune leukocytes that could kill tumor cells and soon after were reported to kill virus-infected cells. In the mid-1980s, 10 years after their discovery, NK cells were also demonstrated to contribute to the fight against bacterial infection, particularly because of crosstalk with other leukocytes. A wide variety of immune cells are now recognized to interact with NK cells through the production of cytokines such as interleukin (IL)-2, IL-12, IL-15 and IL-18, which boost NK cell activities. The recent demonstration that NK cells express pattern recognition receptors, namely Toll-like and nucleotide oligomerization domain (NOD)-like receptors, led to the understanding that these cells are not only under the control of accessory cells, but can be directly involved in the antibacterial response thanks to their capacity to recognize pathogen-associated molecular patterns. Interferon (IFN)-γ is the predominant cytokine produced by activated NK cells. IFN-γ is a key contributor to antibacterial immune defense. However, in synergy with other inflammatory cytokines, IFN-γ can also lead to deleterious effects similar to those observed during sepsis. Accordingly, as the main source of IFN-γ in the early phase of infection, NK cells display both beneficial and deleterious effects, depending on the circumstances

The immune response to infection in the bladder

International audienceThe bladder is continuously protected by passive defences such as a mucus layer, antimicrobial peptides and secretory immunoglobulins; however, these defences are occasionally overcome by invading bacteria that can induce a strong host inflammatory response in the bladder. The urothelium and resident immune cells produce additional defence molecules, cytokines and chemokines, which recruit inflammatory cells to the infected tissue. Resident and recruited immune cells act together to eradicate bacteria from the bladder and to develop lasting immune memory against infection. However, urinary tract infection (UTI) is commonly recurrent, suggesting that the induction of a memory response in the bladder is inadequate to prevent reinfection. Additionally, infection seems to induce long-lasting changes in the urothelium, which can render the tissue more susceptible to future infection. The innate immune response is well-studied in the field of UTI, but considerably less is known about how adaptive immunity develops and how repair mechanisms restore bladder homeostasis following infection. Furthermore, data demonstrate that sex-based differences in immunity affect resolution and infection can lead to tissue remodelling in the bladder following resolution of UTI. To combat the rise in antimicrobial resistance, innovative therapeutic approaches to bladder infection are currently in development. Improving our understanding of how the bladder responds to infection will support the development of improved treatments for UTI, particularly for those at risk of recurrent infection