Delayed Diagnosis of X-linked Lymphoproliferative Syndrome Type 2 in a 17-year-old Male With Severe Crohn's Disease and Recurrent Skin Infections.

X-linked lymphoproliferative syndrome type 2 (XLP2) is a rare genetic primary immunodeficiency disease caused by mutations in the XIAP gene that lead to deficiency of the X-linked inhibitor of apoptosis protein. XLP2 is characterized by dysregulated immune responses and can result in an inflammatory bowel disease (IBD)-like phenotype, a form of monogenic IBD. Patients with XLP2 often succumb to fulminant hemophagocytic lymphohistiocytosis or Epstein-Barr virus infections. Hematopoietic stem cell transplantation (HSCT) is currently the only definitive treatment for XLP2. We report an adolescent with a delayed diagnosis of XLP2 in the setting of severe Crohn's disease diagnosed at age 9 years and recurrent skin infections. He is under evaluation for HSCT. Gastroenterologists must recognize monogenic IBD in patients of all ages with severe disease and signs of an underlying primary immunodeficiency disease. Patients with suspected monogenic IBD should undergo immunologic and genetic analysis at diagnosis to initiate potentially life-saving treatment.

Retrospective analysis of alternate-day prednisone maintenance therapy for Crohn's disease.

We reviewed the medical records of 98 children with Crohn's disease followed at Children's Hospital of Pittsburgh from 1983 to 1993 to evaluate the merits of alternate-day prednisone (AD) maintenance therapy once initial remission was achieved. Of the 98 children, 35 had adequate data recorded for eligibility to the study. Of these, 11 were in the AD group and 24 were in a group whose maintenance regimen did not include prednisone (NO). The dependent variables were frequency of flares and linear growth over time. AD therapy reduced mean symptomatic flares (0.23 +/- 0.1 vs 0.69 +/- 0.14 flares/patient/year; p = 0.04) over a 2-year follow-up period but did not delay significantly the onset of a flare after remission was achieved (16.5 +/- 3.4, vs 13.4 +/- 1.8 months; p = 0.4). Site of disease involvement had no impact on frequency of flares. Fewer patients in the AD group experienced flares, but this finding did not achieve statistical significance (4/11, 36%, vs 17/24, 71%; p = 0.07). Linear growth, measured in height percentile and growth velocity (cm/year), was not significantly reduced by the second year of either therapy. This small retrospective study suggests that AD prednisone therapy may be effective in reducing symptomatic flares in Crohn's patients without a resultant inhibition of linear growth.

Distribution of acute bowel inflammation determined by technetium-labeled white blood cells in children with inflammatory bowel disease.

Knowledge of the distribution of disease in patients with inflammatory bowel disease is important because it has diagnostic, prognostic, and therapeutic implications. We studied 215 patients with 99mTc-HMPAO-white blood cell scans, of whom 80 had Crohn's disease (CD), 34 had active ulcerative colitis (UC), and 31 were controls. In our 77 cases of active CD, uptake was seen exclusively in the small bowel in 18% of patients, only the large bowel in 44%, and both the large and small bowel in 38% of patients. Discontinuous colitis was seen in 63 of these patients. In the 29 cases of active UC, the uptake involved the entire colon in 50% of patients, extended farther than the sigmoid in 27% of patients, and was limited to the rectosigmoid in 23%. In the 29 cases of active UC, four of the scans incorrectly revealed discontinuous accumulation of 99mTc-HMPAO-WBC. In 31 controls, no significant colonic uptake was seen. Isolated small bowel involvement with CD is observed less frequently in children undergoing 99mTc-HMPAO-WBC scanning than in adults. In children, the segmental distribution of inflammation as depicted with 99mTc-HMPAO-WBC is similar to the radiologic distribution.