Significance of clinical-immunological patterns and diagnostic yield of biopsies in microscopic polyangiitis and granulomatosis with polyangiitis.

BACKGROUND: Microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are the two major antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). OBJECTIVES: To characterize a homogenous AAV cohort and to assess the impact of clinicopathological profiles and ANCA serotypes on clinical presentation and prognosis. Clinical differences in GPA patients according to ANCA serotype and the diagnostic yield for vasculitis of biopsies in different territories were also investigated. RESULTS: This retrospective study (2000-2021) included 152 patients with AAV (77 MPA/75 GPA). MPA patients (96.1% myeloperoxidase [MPO]-ANCA and 2.6% proteinase 3 [PR3]-ANCA) presented more often with weight loss, myalgia, renal involvement, interstitial lung disease (ILD), cutaneous purpura, and peripheral nerve involvement. Patients with GPA (44% PR3-ANCA, 33.3% MPO, and 22.7% negative/atypical ANCA) presented more commonly with ear, nose, and throat and eye/orbital manifestations, more relapses, and higher survival than patients with MPA. GPA was the only independent risk factor for relapse. Poor survival predictors were older age at diagnosis and peripheral nerve involvement. ANCA serotypes differentiated clinical features in a lesser degree than clinical phenotypes. A mean of 1.5 biopsies were performed in 93.4% of patients in different territories. Overall, vasculitis was identified in 80.3% (97.3% in MPA and 61.8% in GPA) of patients. CONCLUSIONS: The identification of GPA presentations associated with MPO-ANCA and awareness of risk factors for relapse and mortality are important to guide proper therapeutic strategies in AAV patients. Biopsies of different affected territories should be pursued in difficult-to-diagnose patients based on their significant diagnostic yield.

Reference values for serum lipids and lipoproteins in Spanish adolescents: the AVENA study.

OBJECTIVES: To provide current reference values for serum lipid and lipoprotein levels in Spanish adolescents according to age and sex. METHODS: A cross sectional study conducted in five representative Spanish cities (Granada, Madrid, Murcia, Santander and Zaragoza) including a representative sample of 581 adolescents (299 male and 282 female), aged 13 to 18.5 years. Age- and sex-specific means, standard deviations and percentiles were determined for: Total (TC), high density lipoprotein (HDLc) and low density lipoprotein (LDLc) cholesterol, triglycerides, apolipoprotein A-1 and B-100, and lipoprotein(a). RESULTS: The 90th percentile for TC was 4.95 mmol/L for males and 5.19 mmol/L for females. HDLc levels were significantly higher in females of all age groups. LDLc levels ranged from 2.32 to 2.54 mmol/L in males and from 2.38 to 2.62 mmol/L in females, peaking at 13 years of age in both sexes. Triglyceride levels tended to increase gradually and to peak at 17 years of age for both sexes. Apolipoprotein A-1 and B-100 levels paralleled those of HDLc and LDLc values, respectively. The geometric mean for lipoprotein(a) levels ranged from 0.44 to 0.57 micromol/L in males and from 0.50 to 0.67 pmol/L in females. CONCLUSIONS: The present study provides reference data on the distribution of lipid and lipoprotein levels of Spanish adolescents.