Urine proteomics for discovery of improved diagnostic markers of Kawasaki disease.
Bottom Line: We discovered that urine proteomes of patients with KD, but not those with mimicking conditions, were enriched for markers of cellular injury such as filamin and talin, immune regulators such as complement regulator CSMD3, immune pattern recognition receptor muclin, and immune cytokine protease meprin A.Significant elevations of filamin C and meprin A were detected in both the serum and urine in two independent cohorts of patients with KD, comprised of a total of 236 patients.Notably, meprin A was enriched in the coronary artery lesions of a mouse model of KD.
Affiliation: Division of Hematology/Oncology, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.Show MeSH
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Mentions: In order to validate selected candidate KD markers, we chose to analyse the levels of filamin C and meprin A because of their biological functions that may play a role in KD vide infra and because of availability of commercial ELISAs. We chose to validate candidate markers in urine because of its availability. To assess the KD diagnostic performance of filamin C and meprin A, we prospectively measured their concentrations in the urine of patients, with investigators blinded to the patients' final diagnosis. Patients studied as part of the discovery phase of our study were not included in this validation. We did not find statistically significant differences in total urine protein concentration in the cohort under study (Supporting Information Fig 1). However, urine concentrations of both meprin A and filamin C were significantly elevated in patients with KD as compared to those without, even when corrected for variability in total urine concentration based on urine creatinine (mean filamin C of 19.2 vs. 3.7 ng/ml, and mean meprin A of 50.2 vs. 5.6 ng/ml, two-tailed t-test p = 2.0E−8 and 1.3E−17, respectively, Fig 2A and B, Supporting Information Table 3). Controlling for age, sex, race and duration of fever using logistic regression did not affect the statistical significance of the elevations of meprin A and filamin C. Notably, we found that urine meprin A and filamin C were also significantly elevated in patients with incomplete presentations of KD, meeting only three out of four major diagnostic criteria, as compared to those without KD (mean filamin C of 17.0 vs. 3.7 ng/ml, and mean meprin A of 41.5 vs. 5.6 ng/ml, two-tailed t-test p = 2.7E−6 and 2.2E−6, respectively).
Affiliation: Division of Hematology/Oncology, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.