A decade into the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network and the research is still going strong. In 2017, the MAPP Network published 12 articles of its findings in various medical journals. Researchers from throughout the United States and Canada continue to work together and join resources to make further discoveries to help IC patients.
#1 – In June, the MAPP Network released findings in PAIN: The Journal of the International Association for the Study of Pain. MAPP researchers from across the United States, looked at 52 people (34 women and 18 men) with chronic pelvic pain for one year. Every two years, the patients would have baseline brain imaging and complete a symptom tracker. Researchers found that as chronic pain symptoms tend to change over time that the brain imaging was able to predict those changes with a 73.1 percent accuracy for short-term changes (three months or less). It didn’t seem to relate as much to longer term symptom changes like six to 12 months out. The study provided the first evidence that symptom changes in chronic pain patients may be linked to specific brain networks.
#2 – In July, the MAPP Network released findings in BJU International that examined biomarkers in the urine of chronic pain patients versus healthy controls. The researchers looked specifically for proteins that other studies had associated with chronic pelvic pain: matrix metalloproteinase (MMP)-2, MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex, vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGF-R1) and NGAL. Men with significantly higher concentrations of VEGF, VEGF-R1 and MMP-9 and women with a higher concentration of VEGF concentration were all chronic pelvic pain patients. Their levels were higher than the healthy control group.Some differences were found between men and women as well. For men with pelvic pain, pain and symptom severity seemed to correlate specifically with higher levels of MMP-9, MMP-9/NGAL complex and VEGF-R1. For women with pelvic pain, symptom severity seemed to correlate specifically with higher levels of MMP-9/NGAL complex, pain with higher levels of VEGF and urinary severity with higher levels of MMP-2.In the end, researchers found that men with altered levels of MMP-9, MMP-9/NGAL complex and VEGF-R1 in men and all of the biomarkers in women were all associated with patients who have chronic pelvic pain. While that sounds like a urine test for IC could be in the works, the researchers noted that none of these specific markers were able to actually discriminate well between chronic pelvic pain patients and their healthy counterparts. However, knowing these increased biomarkers coincide with chronic pelvic pain helps them gain insights into the pathophysiology of chronic pelvic pain.
#3 – On Aug. 9, the MAPP Network released findings in Neurology and Urodynamics about the role of c-fibers in stress-induced bladder pain. C-fibers are one of three nerve classes of the central nervous system and the peripheral nervous system. Researchers exposed female rats to water avoidance stress (WAS) for 10 days. They then performed various tests to assess the effect on the rats’ bladders. The study found the rats with WAS urinated earlier than otherwise they would have, meaning that chronic stress enhances the nerve response in bladders. Researchers concluded the sensitized C-fibers play a role in stress-induced bladder pain symptoms.
#4 – On Sept. 8, the MAPP Network released the same findings in PLOS One, adding that the WAS rats may be a good animal model for working on brain phenotypes of humans with IC.
#5 – In September, the MAPP Network released findings in The Journal of Urology. Researchers from across the United States conducted a yearlong observational study of 233 women and 191 men with chronic pelvic pain. Once a week, patients used a body map to mark what areas of the body they had felt pain in during the last week. Of the patients enrolled in the study, 25 percent reported only pelvic pain. The remaining 75 percent experienced pain beyond the pelvis, and 38 percent of those patients reported widespread body pain. Unsurprisingly, the study also found that patients with more pain locations had a greater severity of pain in general and a higher level of sleep disturbance, depression, anxiety and psychological stress. These patients also had a worse quality of life. Researchers concluded that 3/4 of people with chronic pelvic pain also report pain outside the pelvis. Chris Payne’s subtyping system places patients with multiple pain disorders in IC/BPS Subtype 5 – Central Sensitization.
#6 – In October, the MAPP Network released the findings in the Journal of Urology that examined 221 female and 176 male chronic pelvic pain patients for a year throughout the United States. Researchers were looking at the baseline clinical and psychosocial characteristics of patients. A majority of the patients (60 percent) had stable symptoms throughout the year with only 13 percent worsening and 22 percent improving. Researchers found that pain and urinary outcomes were impacted by the extent of widespread pain and poorer overall health. While anxiety, depression and general mental health did not significantly predict the patients’ outcomes, pain catastrophizing and self-reported stress did impact the patients’ outcomes. Researchers concluded that non-urological symptoms and poorer general health are risk factors for poorer pain and urinary symptom outcomes in patients. As a result, researchers see a need for broad-based assessment of chronic pelvic pain.
#7 – Also in October, the MAPP Network released findings in BJU International examining whether treatment with VEGF neutralizing antibodies can reduce pain and voiding dysfunction in mice with induced cystitis. In findings published in July (see number 2), researchers had found that VEGF proteins were found in the urine of chronic pain patients. They concluded that blocking the VEGF proteins with antibodies was effective in reducing pelvic and bladder pain in the mice. The researchers said more studies are needed to determine how antibodies could manage bladder pain.
#8 – Also in October, the MAPP Network released findings in PAIN: The Journal of the International Association for the Study of Pain that examined the impact of pain on the brain. Researchers used data from 1,079 patients and compared patients with chronic pelvic pain with both pain-free controls and fibromyalgia patients. The researchers found that patients with chronic pelvic pain showed increased brain gray matter volume and other changes. They determined that widespread pain is associated with reduced mental and physical function, no matter how severe or mild pain is. Researchers concluded that IC patients could benefit from treatments that target the central nervous system.
#9 – On Nov. 15, the MAPP Network released findings in NeuroImage: Clinical. Researchers looked at brain imaging of female patients with chronic pelvic pain to determine whether they had abnormal concentrations of brain metabolites, specifically in regions that process and modulate pain. Compared to a control group of patients without pain, the patients with chronic pelvic pain had significantly higher levels of choline. And those higher choline levels also correlated with negative moods. The researchers concluded that their findings suggest that choline may be related to IC.
#10 – Also in November, the MAPP Network released findings in the Journal of Psychosomatic Research looking at chronic prostatitis/chronic pelvic pain patients to determine how much of a role that genetics play in their having both chronic pelvic pain and other chronic pain conditions. Using data from 6,824 male twins, they found that there were significant associations between chronic prostatitis and the six the other chronic pain conditions they looked at: fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, temporomandibular disorder, tension headaches and migraine headache. The researchers also found that familial factors play a role in these conditions co-existing together. However, factors are only a partial explanation for the high co-morbidity between chronic prostatitis and the other pain conditions. More research is needed to determine the role of genetic and environmental factors as well.
#11 – Published first electronically on Nov. 8 and then in print on March 1, the MAPP Network released findings in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology that examined the role of a specific enzyme, acyloxyacyl hydrolase (AOAH), in pelvic pain. Using mice who were modified to have symptoms of IC, the researchers found that the mice all had an immune reaction in the areas of the brain that correlate with pelvic pain. The mice, who were AOAH deficient, had significantly higher levels of bladder vascular endothelial growth factor, which seems to be a direct correlation to chronic pelvic pain. The researchers concluded that a variation in AOAH influences pelvic pain in IC.
#12 – Published electronically on Dec. 5 and then in print on Dec. 27, the MAPP Network released findings in the Journal of Urology studying triggers that have been reported to induce flares in IC patients. The researchers worked with 292 participants who answered questionnaires up to three time during a flare and three randomly selected times. Their objective was to more scientifically examine how much various activities impact IC flares. They looked at things like diet, physical activities, sedentary behaviors, stress, sexual activities, infection-like symptoms and allergies. They found that only recent sexual activity and urinary tract infection symptoms (which may overlap) were actually associated with the onset of an IC flare. They concluded that other than sexual activity, other potential triggers for IC flares are not consistent throughout IC patients and may be more individualized. As such, they recommended caution in following rigid global flare prevention strategies and said further research is needed to develop evidence-based strategies.