S1535 Systematic Review of Hermansky-Pudlak Syndrome-Associated Colitis: Clinical Presentation, Diagnostic Features, Treatment Responses, and Outcomes

Introduction: Hermansky-Pudlak Syndrome (HPS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism, platelet dysfunction, and granulomatous colitis that clinically resembles inflammatory bowel disease (IBD). Due to significant diagnostic overlap, accurate identification of HPS-associated colitis is frequently delayed, affecting patient outcomes. Methods: A systematic review was performed in accordance with PRISMA guidelines. A comprehensive search of PubMed and Google Scholar identified 928 records. After removing 595 duplicates, 333 articles were screened, with 93 full texts reviewed. Ultimately, 29 case reports or series describing 46 unique patients with confirmed HPS-associated colitis were included. Patient demographics, clinical presentations, diagnostic delays, therapeutic strategies, and clinical outcomes were systematically evaluated. Results: Patients presented at a median age of 47 years, predominantly women (54%), with significant representation from Puerto Rican ancestry (46%). Common presenting symptoms included diarrhea (80%), hematochezia (78%), abdominal pain (70%), and fever (17%). Notably, diagnostic delays were extensive, commonly due to initial misdiagnoses as Crohn’s disease or infectious colitis. Therapeutically, biologics (used in 61% of cases) demonstrated superior efficacy compared to steroids (63%), immunomodulators (59%), and 5-ASA (43%). ICU admissions occurred in 9%, primarily due to severe hemorrhagic complications, and overall mortality was high at 13%, mostly related to multisystem organ failure post-surgery. Conclusion: HPS-associated colitis presents considerable diagnostic challenges, with frequent misdiagnoses and treatment complexities. Biologics emerge as the most effective therapeutic option. Increased awareness and early differentiation from classic IBD are essential to reduce diagnostic delays and improve outcomes.