Tan, Xiaoqing

Abstract Background Persistent organ failure (POF) is the strongest determinant of mortality in acute pancreatitis (AP). There is a paucity of data regarding the impact of different POF attributes on mortality and the role of different characteristics of systemic inflammatory response syndrome (SIRS) in the risk of developing POF. Objective We aimed to assess the association of POF dynamic features with mortality and SIRS characteristics with POF. Methods We studied 1544 AP subjects prospectively enrolled at 22 international centers (APPRENTICE consortium). First, we estimated the association of onset, duration, and maximal score of SIRS with POF. Then, we evaluated the risk of mortality based on POF onset, duration, number, type, and sequence of organs affected. Analyses were adjusted for potential confounders. Results 58% had SIRS, 11% developed POF, and 2.5% died. Early SIRS, persistent SIRS, and maximal SIRS score ≥ 3 were independently associated with higher risk of POF ( p < 0.05). Mortality risk in POF was higher with two (33%, odds ratio [OR] = 10.8, 3.3–34.9) and three (48%, OR = 20.2, 5.9–68.6) organs failing, in comparison to single POF (4%). In subjects with multiple POF, mortality was higher when the cardiovascular and respiratory systems failed first or concurrently as compared to when the renal system failed first or concurrently with other organ ( p < 0.05). In multivariate regression model, the number and sequence of organs affected in POF were associated with mortality ( p < 0.05). Onset and duration of POF had no impact mortality. Conclusion In AP patients with POF, the risk of mortality is influenced by the number, type, and sequence of organs affected. These results are useful for future revisions of AP severity classification systems.

Abstract Background Immunoglobulin G subclass 4 (IgG4) is hypothesized to play an immunomodulatory role, downregulating humoral immune responses. The role of this anti-inflammatory molecule in inflammatory bowel disease (IBD) has not been fully characterized. We sought to define alterations in serum IgG4 in patients with IBD and their association with multiyear disease severity. Methods We analyzed metadata derived from curated electronic health records from consented patients with IBD prospectively followed at a tertiary center over a 10-year time period. Patients with IBD with IgG4 serum levels available formed the study population. Demographics and multiyear clinical data were collected and analyzed. We stratified patients with IBD with low, normal, or high serum IgG4 levels. Results We found IgG4 characterized in 1193 patients with IBD and low IgG4 levels in 233 patients (20%) and elevated IgG4 levels in 61 patients (5%). An IgG4 deficiency did not significantly correlate with other antibody deficiencies. In a multiple Poisson regression analysis, low IgG4 was associated with more years on biologic agents (P = 0.002) and steroids (P = 0.049) and more hospital admissions (P &lt; 0.001), clinic visits (P = 0.010), outpatient antibiotic prescriptions (P &lt; 0.001), and CD-related surgeries (P = 0.011) during the study period after controlling for certain confounders. Elevated IgG4 was only associated with primary sclerosing cholangitis (P = 0.011). A cohort of patients with IgG4-deficient severe IBD received intravenous Ig replacement therapy, which benefited and was continued in 10 out of 11 individuals. Conclusions An IgG4 subclass deficiency, distinct from other antibody deficiencies, occurred commonly in a referral IBD population and was associated with multiple markers of disease severity. This is the first association of IgG4 subclass deficiency with an inflammatory disease process. Further work is needed to define the mechanistic role of IgG4 deficiency in this severe IBD subgroup.