NMO is a neurological autoimmune disease, and therefore having a strong understanding of both neuroscience and immunology (the study of the immune system) is vital to improved targeted treatment, and ultimately a cure for this disease and related diseases. Keep up with this page for recent research updates on basic science, immunotherapies, neurology news, nerve repair research and more.
Emerging Immunotherapy Research:
NPR reports on a potential emerging breakthrough in multiplesclerosis treatment: immunotolerance. The concept is to identify antigens, or the particular components that the immune system is reacting against, and induce tolerance, or lack of response. Think of the approach done for allergy treatment. Researchers are realizing there is most likely a number of factors/antigens driving the autoimmune response, but the more they are able to identify, the more hopeful the effectiveness of this potential treatment approach. Read the NPR report.
Theories Behind Autoimmune Disease:
Why Do Autoimmune Diseases Occur More Frequently in Females?
'Pregnancy Compensation Hypothesis'
Autoimmune disease overwhelmingly affects females more than males. In NMO, the female-male ratio can be about 9:1. In multiple sclerosis, this female-male ratio is about 2-3:1. This pattern of higher female-male proportion is seen in a number of other autoimmune diseases. Why? Science hasn't been able to answer that yet, but there are a lot of ideas. Some have speculated it's hormonal, but that doesn't seem to completely explain it. Others have suggested it has to do with females having two X chromosomes, compared to the one X and one Y males (in almost all cases) possess. Still that doesn't seem to accurately support the high degree of autoimmunity in females. Many have offered that differential genetic expression seems to confer a hyperactive immune response that predisposes women to a higher frequency of autoimmunity. But it's not all bad for females- there seems to be an overall decreased risk of cancer.
Researcher Melissa Wilson and colleagues propose that human ancestral immunity has been strongly determined by distinct immune regulation during pregnancy, termed the 'pregnancy compensation hypothesis.' Interestingly, pregnancy has been associated with a quieting of autoimmune disease activity. Citing our hunter-gatherer ancestors, the authors point out that most females back then spent the majority of their adulthood pregnant or lactating. Since then, the incidence of autoimmunity has been on the rise- again, particularly in women. They speculate that this chronic reproductive phase probably led to long-term modulation of the maternal immune system. This regulation evolved to help the pregnant female with an invasive placenta and potentially immunologically challenging pregnancy. In general, the immune system works to defend the body against invaders, anything that might appear foreign or not 'self.' That could potentially be really dangerous though during pregnancy, if the immune system deemed the fetus a 'foreign invader.' The body has a solution to that! During pregnancy, a women's immune system is altered, in some ways 'turned down' or shifted away from an inflammatory state to help make sure the fetus isn't targeted as a 'foreign invader' by the mother's immune cells. However, the immune system does need to be on guard to defend mother and baby from danger, such as infections or cancer. Therefore, other components of the immune system outside of the womb might be primed to be on high alert.
The 'pregnancy compensation hypothesis' speculates that sex differences observed in immune function might be resultant in part by evolution of gene content and sex chromosome dosage (remember, X and Y chromosomes), as well as reproductive hormones. Wilson and colleagues also cite the effect of industrial environmental factors that may further contribute to this heightened state of immune function found in females. These multifactorial environmental factors include increased reproductive hormones, decreased reproductive time, obesity, and decreased infections, particularly parasitic. The latter refers to another hypothesis to account for rising autoimmune disease: the hygiene hypothesis. This concept centers around our ancestral immune system having encountered a high number of parasitic and other infections that 'trained' the immune system over time. Without these particular 'bad guys' around as much, our immune system might be shifted to an altered profile that favors autoimmunity. In summary, Wilson and colleagues hypothesize that the maternal immune system evolved to account for tolerance to pregnancy, while still defending the pregnant female from infection. But the immune system has become 'mismatched' with the industrialized environment, favoring an increased incidence of autoimmunity and overall decreased risk of cancer in females compared to males.
Many questions remain to be answered around this hypothesis. Should women be pregnant all the time? Obviously no. There are a number of health risks with pregnancy too, and not all women are able to become pregnant. Also, it seems like there can be benefit of this hyperactive immune system in females, with the potential overall decreased cancer susceptibility compared to males. How many pregnancies are seemingly necessary to account for these changes? What exactly is pregnancy doing to the immune system? Do nonindustrialized areas have these sex differences in autoimmunity? Wilson and her colleagues are excited to help answer these questions with what they believe to be a testable hypothesis.
Want to learn more? Read the full article below:
The Atlantic also wrote a nice piece on it: