[Serological and genetic markers in the diagnosis and follow-up of coeliac disease]. / Marcadores serológicos y genéticos en el diagnóstico y seguimiento de la enfermedad celíaca.

INTRODUCTION: Understanding of celiac disease has changed with the advent of serological markers (antigliadin IgA, anti-endomysial IgA and anti-transglutaminase IgA antibodies) and with the identification of major susceptibility genes (HLA-DQA1*05-DQB1*02). Reports of the efficacy of these diagnostic tests have varied, depending on the methodology used and the population investigated. OBJECTIVES: To determine the clinical utility of genetic and serological markers in the diagnosis of celiac disease, their relationship with histological lesions and their changes during treatment, in order to establish an optimal diagnostic algorithm in our environment. PATIENTS AND METHODS: We performed a retrospective study of 590 patients from the health area of Badajoz referred to the Immunology Laboratory for screening or follow-up of celiac disease. The results of intestinal histology, serological markers (antigliadin IgA, anti-endomysial IgA and anti-transglutaminase IgA antibodies), and genomic typing (HLA-DQA1*05-DQB1*02) were analyzed. RESULTS: The sensitivity and specificity of serological tests were greater than 90 %, with a negative predictive value of 98-100 %. HLA-DQA1*05-DQB1*02 was detected in 97 % of celiac patients, with a very high negative predictive value (99 %). On biopsy, 95 % of the patients with some grade of intestinal lesion were positive for antigliadin and/or anti-endomysial antibodies. CONCLUSION: To avoid missed diagnoses, the diagnostic algorithm of celiac disease should include at least two serological markers (antigliadin antibodies and anti-endomysial and/or anti-transglutaminase antibodies) and IgA quantification. Genomic typing should be carried out if one or more markers are positive or if the subject belongs to any of the risk groups. The physician should decide on the advisability of intestinal biopsy on the basis of the patient's clinical and immunological history.

[Antineutrophil cytoplasmic antibodies (ANCA): clinico-pathologic correlations iin a series of 82 cases]. / Anticuerpos frente al citoplasma de los neutrófilos (ANCA): correlaciones clínico-patológicas de una serie de 82 casos.

OBJECTIVE: Antineutrophil cytoplasmic antibodies (ANCA) have been described in a great variety of diseases in addition to the ANCA-associated systemic vasculitis (Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and Churg-Strauss syndrome (CSS)) and the pauci-immune rapidly progressive glomerulonephritis (RPGN). The objective of this work is to describe the clinical-pathological diagnosis of a series of patients with ANCA. MATERIAL AND METHODS: Retrospective review of patients with positive ANCA by indirect immunofluorescence in our hospital between January 1997 and December 1998. RESULTS: We identify 82 patients with ANCA. Six cases (7.3%) showed a C-ANCA pattern, 19 (23.2%) a P-ANCA pattern and 57 (69.5%) an atypical pattern. Eight patients (9.7%) had an ANCA-associated systemic vasculitis (5 WG, 2 MPA and 1 SCS). Four patients (4.9%) had a pauci-immune RPGN without systemic vasculitis. One only case (1.2%) in our series presented a C-ANCA pattern without evidence of an ANCA-associated systemic vasculitis or a pauci-immune RPGN. CONCLUSIONS: The atypical pattern is the most frequent in patients with ANCA. A minority of patients with ANCA have an ANCA-associated systemic vasculitis (WG, MPA or SCS) or a pauci-immune RPGN. The occurrence of a C-ANCA pattern is exceptional in patients without an ANCA-associated systemic vasculitis or a pauci-immune RPGN.