Abstract Gastrointestinal manifestations of RA are rare and typically secondary to vasculitis, amyloidosis, or medication toxicity. Autoimmune enterocolitis (AI-E) is an exceptionally rare severe extra-articular manifestation of RA that may lead to life-threatening malabsorptive colopathy. We report a case of AI-E in a patient with newly diagnosed RA presenting with multiorgan dysfunction. Case Presentation A 61-year-old woman with recently diagnosed seropositive RA on escalating doses of methotrexate and hydroxychloroquine for the management of severe symptomatic arthritis presented with several weeks of profuse watery diarrhea, vomiting, and weight loss. She was admitted comatose with septic-appearing shock, severe lactic-acidosis(13.9 mmol/L) refractory to volume and blood resuscitation requiring intubation. Laboratory evaluation revealed profound pancytopenia, hypoalbuminemia (1.5 g/dL), trace element deficiencies, avitaminosis, elevated fecal calprotectin (5200 µg/g) (Table 1). Methotrexate levels were normal and MRI brain was negative for toxicity signals however showed multiple cerebellar infarctions. Abdominal imaging showed diffuse enterocolitis with colonic dilation but no ischemia. Infectious, autoimmune, and malignant workups were negative. She was managed clinically for sepsis and started on TPN for nutritional support. Empiric high-dose corticosteroids led to rapid improvement in cytopenias. Duodenal and colonic biopsies showed chronic mucosal inflammation without granulomas or dysplasia, consistent with AI-E. She achieved marked clinical and nutritional recovery following a six-week corticosteroid taper, with normalization of cell-counts and micronutrients. Discussion AI-E as an extra-articular manifestation of RA early in the disease course is extremely rare. There has only been 2 case reports in literature as of this date1,2. The combination of severe malabsorptive colopathy, cytopenias, and encephalopathy in the absence of proven infection, immunodeficiency, amyloid, vasculitis or malignancy should raise suspicion for AI-E. One of the criteria for diagnosis of AI-E, involves presence of autoimmunity which ranges from a simple thyroid condition to cancers with autoimmunity like thymoma(3). From a histopathology four subtypes have been described: active chronic enteritis (52%), celiac disease-like (20%), graft-versus-host disease-like (16%), and mixed/no predominant pattern (12%). Although these seem distinct, an overlap of histologic findings is always almost present. Methotrexate toxicity can cause non-ischemic colitis and must be ruled out. The observed clinical and biochemical response to corticosteroids reinforces the immune-driven pathophysiology. Heightened clinical vigilance for AI-E in patients with systemic autoimmune disease and unexplained malabsorption is essential to enable timely diagnosis and immunosuppressive intervention. Conclusion Early recognition of RA-induced fulminant AI-E and empiric immunosuppression is essential, as it can rapidly reverse systemic inflammation and restore intestinal function. This abstract is funded by: NA
Ashraf et al. (Fri,) studied this question.