Ulcerative colitis and antineutrophil cytoplasmic antibodies in Hong Kong Chinese

Inflammatory bowel diseases are known to be rare among the Chinese. The diagnosis of ulcerative colitis has been difficult in some of the Asian countries where infective colitis is more prevalent. Twenty-three Hong Kong Chinese patients diagnosed to have ulcerative colitis were reviewed. The symptoms were relatively mild and extraintestinal manifestation had been rare. Patients responded well to steroid therapy and sulfasalazine. Three patients in this series were found to have cyst and/or trophozoites of Entamoeba histolytica in stool. In this series, 19 patients were tested for antineutrophil cytoplasmic antibody (ANCA). Fourteen patients (73.5%) were positive, of which six (31.5%) showed a perinuclear staining pattern and eight (42%) demonstrated a cytoplasmic pattern. Five patients (26.5%) were negative for any ANCA, and none was positive for both. Sera of these patients were also tested for anti-alpha granules, anti-myeloperoxidase, and anti-lactoferrin activities. None was positive. Control sera collected from 16 patients with irritable bowel syndrome were all negative for the tests. In conclusion, testing of ANCAs may help in making the diagnosis of idiopathic inflammatory bowel disease in difficult situations.