Diagnostic value of distinguishing and reporting different perinuclear ANCA (P-ANCA) immunofluorescence patterns: a prospective study.

OBJECTIVES: To investigate whether discriminating the classic perinuclear antineutrophil cytoplasmic antibody (P-ANCA) pattern from atypical P-ANCA and uninterpretable patterns improves the diagnostic utility of ANCA testing. METHODS: All ANCA requests (n = 3,544) referred to Pathology Queensland were analyzed prospectively over 4 months for P-ANCA pattern subtypes and myeloperoxidase (MPO)-ANCA/PR3-ANCA results and correlated with clinical, laboratory, and radiologic evidence of necrotizing small vessel vasculitis. RESULTS: Of the 436 perinuclear immunofluorescence-positive samples, 45 were classic P-ANCA, 163 were atypical P-ANCA, and 228 were antinuclear antibodies/uninterpretable. The classic P-ANCA pattern had a significantly stronger association with vasculitis (30/45) than atypical P-ANCA (2/163) (P <.0001) or ANA/uninterpretable patterns (8/228) (P <.0001). The combination of a classic P-ANCA pattern and positive MPO-ANCA/PR3-ANCA result was also more strongly associated with vasculitis than a positive MPO-ANCA/PR3-ANCA result in isolation (P = .003). CONCLUSIONS: This study demonstrates that reporting different P-ANCA patterns (including ANA/uninterpretable patterns) provides additional diagnostic information to MPO-ANCA/PR3-ANCA results.

Paediatric intussusception: epidemiology and outcome.

OBJECTIVES: (i) To describe the clinical presentation of intussusception and determine features associated with earlier diagnosis; (ii) to describe outcomes of children diagnosed with intussusception; and (iii) to determine whether time to diagnosis is associated with poorer prognosis. METHODS: A retrospective review was performed of all patients presenting to a tertiary paediatric hospital with a diagnosis of intussusception during a 10 year study period. RESULTS: One hundred and forty-one confirmed cases met the inclusion criteria, giving an incidence of one case per 1450 ED presentations. The median age of presentation was 9 months, with a ratio of male to female of 2:1. Three or more of the four 'classic' features of intussusception (vomiting, abdominal pain, bloody/red currant jelly stool, or abdominal mass) were reported in only 46% of presentations. Median time to confirmation of diagnosis was 19 h from onset of symptoms. Ultrasound was the most commonly employed method used to confirm the diagnosis. Air enema had a success rate of 80%, with a reduced success rate beyond the first attempt. Early diagnosis was associated with decreased frequency of surgical intervention and need for bowel resection. CONCLUSION: The 'classic' picture of intussusception might frequently not be present in children with intussusception. Reliance on 'classic' features alone might delay diagnosis. Delayed diagnosis is associated with poorer patient outcomes. Air enema has a high success rate for reduction of intussusception.