Do we need to measure total serum IgA to exclude IgA deficiency in coeliac disease?

BACKGROUND: Screening for IgA deficiency in patients with coeliac disease is essential because of the increased incidence of IgA deficiency associated with the disease, which usually relies on the estimation of IgA levels in each case. AIM: To devise a method of excluding IgA deficiency without measuring total serum IgA in each case. MATERIALS AND METHODS: The optical density readings on enzyme-linked immunosorbent assay (ELISA) of 608 routine samples received for tissue transglutaminase (TTG) antibody testing for coeliac disease were compared with their total IgA concentrations. Dilution experiments were also carried out to ensure linear relationships between optical density on ELISA and IgA concentrations and to compare the sensitivities for TTG and endomysium antibodies in TTG-positive samples. RESULTS AND DISCUSSION: A clear relationship was shown between total IgA concentration and TTG optical density readings by ELISA. To ensure a positive TTG result if antibodies are present, it was possible to recommend an optical density level above which all samples have sufficient IgA. Samples with optical density <0.05 should be investigated further by estimating total IgA and, if low, samples should be subjected to immunofluorescence microscopy testing for IgA and IgG endomysium antibodies. CONCLUSIONS: An easier, more cost-effective and practical way of excluding IgA deficiency in the investigation on coeliac disease is reported.

The effect of a symptom related "gating policy" on ANCA requests in routine clinical practice.

BACKGROUND: Most positive antineutrophil cytoplasmic antibody (ANCA) results are associated with non-vasculitic conditions, and guidelines have been proposed for the judicious use of this test. The outcome of applying similar guidelines in a routine laboratory is reported. METHODS: All immunology requests (6500) over six months were selected, and those requesting ANCA were studied for the appropriateness of the clinical data supporting the request, the presence of ANCA in those samples tested, and the final diagnosis. Antibodies were detected by indirect immunofluorescence. RESULTS: ANCA testing was requested in 287 samples. Application of a "gating policy", which refuses analysis on requests that are not supported by clinical data suggestive of systemic vasculitis, made clinicians more selective about the patients for whom they requested ANCA testing. The percentage of "appropriate" screens for systemic vasculitis was relatively high (212 of 287 requests: 72.5%). Only one of the remainder, for whom ANCA testing was initially refused, developed an ANCA related systemic vasculitis in the two years after the study, but the delay in reporting her positive ANCA was only two days. Most of the samples tested were negative (155 of 212), but most (42 of 57) of the patients with positive ANCA results were found to have a systemic vasculitis. CONCLUSIONS: A gating policy to select requests supported by clinical data suggestive of systemic vasculitis makes ANCA testing more clinically relevant and cost effective. Studies where guidelines can be proposed and their effects measured are important in the light of clinical governance and evidence based medicine.

[Lyme disease in Upper Normandy: report of a hospital survey]. / Maladie de Lyme chez l'enfant en Haute-Normandie: à propos d'une enquête hospitalière.

This study presents the results of a hospital survey on Lyme disease in children living in upper Normandy, a region that is quite densely wooded (with 18% forest areas and woods). The aim of this survey was to assess the prevalence of this disease in children from the Seine-Maritime and L'Eure, hospitalized in pediatric wards in the Seine-Maritime department, which includes Rouen, Dieppe, Fécamp, Elbeuf, and Le Havre. Fifteen cases of Lyme disease were diagnosed between September 1988 and June 1997. The children (6 girls and 9 boys) were aged between 5 and 14 years old. Only 7 subjects showed primary symptoms, while secondary symptoms were observed in 12 children. In the study population, a high prevalence (11 out of the 15 children) of neurological disorders was found. The following secondary symptoms were noted: 5 cases of erythema migrans, 2 cases of non-malignant cutaneous lymphocytoma, and 4 cases which in fact had previously displayed primary clinical signs (3 subjects with erythema migrans and 1 subject with non-malignant cutaneous lymphocytoma); 7 cases of uni- or bilateral facial paralysis, the most frequent neurological manifestation with or without lymphocytic meningitis; 1 case of central vestibular syndrome with a hyperalgesic meningoradicular reaction in the vicinity of the tick bite; 1 case of peripheral radicular involvement and intense pain in the left lower limb; 4 cases of ocular disorders (3 diplopias, 1 bilateral conjunctivitis complicated by kerato-uveitis, 1 bilateral complete cecitis). Only 10 child had rheumatological symptoms, i.e., Lyme arthritis of the right knee. Treatment consisted of amoxicillin (10 children) administered at a dosage of 50 to 100 mg/kg/d over a period ranging from 10 days to 1 month, or ceftriaxone (7 children) at a dosage of 50 to 100 mg/kg/d administered intravenously over a period ranging from 8 days to 3 weeks. Two of the children received combined antibiotic therapy, and 5 subjects had adjunct corticotherapy.