Background: Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism, platelet storage pool deficiency and systemic complications associated with ceroid deposition in the reticuloendothelial system. HPS types 1 and 4 are associated with Crohn's disease (CD)-like gastrointestinal disorders, such as granulomatous enterocolitis or perianal disease. Cases of colitis can be particularly severe and, before the use of anti-tumor necrosis factor alpha (TNFα) therapy had become common, were reported as showing poor responsiveness to medical treatment.
Case summary: We present the case of a 51-year-old albino woman who presented with acute severe colitis that led to the diagnosis of HPS. Histologic findings of biopsy samples showed chronic inflammation with deep ulcerations, and granulomas without caseous necrosis. Molecular genetic analysis confirmed HPS type 1, with a homozygous 27 base-pair deletion in exon 20 of the HPS1 gene. Once the patient's bleeding diathesis was corrected by platelet transfusion, the granulomatous colitis responded dramatically to a medical treatment regimen that included corticosteroids, azathioprine and infliximab; this regimen is similar to that used in CD treatment. Although it remains unclear if the granulomatous enterocolitis in HPS is due to ceroid deposition or reflects the co-existence of CD and HPS, the fact that this case of HPS-related granulomatous colitis responded to the same therapeutic approach used in CD suggests that this type of colitis may result from HPS patients' genetic susceptibility to CD.
Conclusion: We report a case of severe colitis that led to the diagnosis of HPS, which was responsive to azathioprine and infliximab.
Keywords: Acute severe colitis; Azathioprine; Case report; Hermansky-Pudlak syndrome; Inflammatory bowel disease; Infliximab.