Polyarteritis nodosa in Croatian children: a retrospective study over the last 20 years.

To analyze the disease characteristics, treatment modalities and outcome of polyarteritis nodosa (PAN) in Croatian children. Cross-sectional study included all children with PAN diagnosed according to EULAR/PRES/PRINTO criteria during the last two decades. PAN was diagnosed in 12 patients (6 girls and 6 boys) mean age (±SD) 11.33 ± 3.08 years. The share of PAN among all vasculitides was 3.8 %. Systemic PAN was diagnosed in 7 children (58 %), microscopic polyangiitis in 3 (25 %), cutaneous PAN in 2 (17 %). The most consistent symptoms were skin involvement (90 %) and arthritis/arthralgia (60 %). The CNS was affected in 33 % of patients. Inflammatory markers (C-reactive protein and erythrocyte sedimentation rate [ESR]) were elevated in all patients, and anti-neutrophil cytoplasmatic antibodies were positive in all patients with microscopic polyangiitis. Therapy mode for all patients was corticosteroids. Immunosuppressive drugs were used as additional therapy for patients with severe symptoms. Two patients (17 %), both suffering from microscopic polyangiitis, died due to renal failure during the follow-up. In comparison with available studies, we found a difference in distribution of childhood polyarteritis nodosa as well as some clinical characteristics (e.g., higher prevalence of neurological and pulmonary symptoms), while other researched features, laboratory and treatment were similar.

5-azacytidine enhances proliferation in transplanted rat fetal epiglottis.

Fetal rat epiglottis and its developmental potential in ectopic transplants under the influence of the epigenetic drug was investigated. Epiglottises from 17-days-old rat embryos were transplanted under kidney capsules of adult rats for 14 days. 5-azacytidine (5 mg/kg) was injected intraperitoneally during first three days and controls were sham treated. TEM, immunohistochemical detection and quantitative stereological analysis of the Proliferating Cell Nuclear Antigen (PCNA) expression (numerical density N(v)) were performed. Typical chondroblasts with long surface processes and sparse lipid droplets were found in fetal epiglottis and chondrocytes with shorter processes, numerous lipid droplets and elastic fibers in adult. PCNA was expressed in almost all cells of the fetal epiglottis while in the adult it was expressed in minority of cells. In transplants, differentiation progressed towards the differentiation found in the adult. Application of 5-azacytidine increased the capacity for proliferation (N(v PCNA)) in comparison to controls but no difference in differentiation was observed. Data about the developmental potential and induction of proliferation in mammalian epiglottis by epigenetic modulation is of importance for regenerative medicine.