Chronic Non-Bacterial Osteomyelitis (CNO) is an inflammatory disorder that primarily affects children. Although underestimated, its incidence is rare. For these reasons, no diagnostic and no therapeutic guidelines exist. The manuscript wants to give some suggestions on how to deal with these patients in the every-day clinical practice. CNO is characterized by insidious onset of bone pain with local swelling. Systemic symptoms such as fever, skin involvement and arthritis may be sometimes present. Radiological findings are suggestive for osteomyelitis, in particular if multiple sites are involved. CNO predominantly affects metaphyses of long bones, but clavicle and mandible, even if rare localizations of the disease, are very consistent with CNO diagnosis. CNO pathogenesis is still unknown, but recent findings highlighted the crucial role of cytokines such as IL-1β and IL-10 in disease pathogenesis. Moreover, the presence of non-bacterial osteomyelitis among autoinflammatory syndromes suggests that CNO could be considered an autoinflammatory disease itself. Differential diagnosis includes infections, malignancies, benign bone tumors, metabolic disorders and other autoinflammatory disorders. Radiologic findings, either with Magnetic Resonance or with Computer Scan, may be very suggestive. For this reason in patients in good clinical conditions, with multifocal localization and very consistent radiological findings bone biopsy could be avoided. Non-Steroidal Anti-Inflammatory Drugs are the first-choice treatment. Corticosteroids, methotrexate, bisphosphonates, TNFα-inhibitors and IL-1 blockers have also been used with some benefit; but the choice of the second line treatment depends on bone lesions localizations, presence of systemic features and patients’ clinical conditions. CNO may be difficult to identify and no consensus exist on diagnosis and treatment. Multifocal bone lesions with characteristic radiological findings are very suggestive of CNO. No data exist on best treatment option after Non-Steroidal Anti-Inflammatory Drugs failure.

Behçet’s disease is a rare multi-systemic inflammatory disease with unknown etiology which involves principally oral and genital mucosa, skin and eyes. Average age at onset of the disease is about 25-30 years, but it may be diagnosed before the age of 16. It is not very rare in Italy, even though there are limited data concerning epidemiology. Aim of this study is to describe the baseline data of an Italian cohort of patients with as having BD or probable BD. We described the baseline data of the first national epidemiological study on children coming from 16 Italian Pediatric Rheumatologic Centers diagnosed by the treating physicians as having Behçet’s Disease. Data on demographic characteristics, clinical features and therapy were collected. We then compared our findings to those of international pediatric cohort studies and also retrospectively evaluated the ability to diagnose BD using ISG, ICBD and, for the first time, the new PEDBD criteria. The study included 110 patients (62 M, 48F). Average age at onset was 8.34±4.11 years. The frequencies of signs/symptoms were: recurrent oral aphtosis 94.5%, genital ulcers 33.6%, ocular 43.6%, gastrointestinal 42.7%, musculoskeletal 42.7%, neurological 30.9% and vascular involvement 10%. Thirty-two patients (29.1%) fulfilled ISG, 78 (70.9%) ICBD, 50 (45.5%) PEDBD criteria and 31 (28%) didn’t fulfill any of them. The most frequently used treatments were colchicine and corticosteroids followed by immunosuppressants. Four patients received biologic therapy (anti TNF-α and anti-IL-1) to treat severe organ involvement. Recurrent oral aphtosis was the most frequent clinical manifestation, followed by ocular involvement. Gastrointestinal lesions were more frequent in Italy than in non-European countries as opposed to genital ulcers. Skin, ocular and vascular manifestations had a higher frequency in males and genital ulcers in females. Constitutional symptoms were present in 44.5% and recurrent fever in one third of our population.

Anti-transglutaminase antibodies are the diagnostic markers of coeliac disease. A role is suggested for infectious agents in the production of anti-transglutaminase antibodies. The aim was to measure positive anti-transglutaminase antibody levels in children with infectious diseases and to compare immunological and biological characteristics of the anti-transglutaminase antibodies derived from these children with that from coeliac patients. Two hundred and twenty-two children suffering from infectious diseases were enrolled prospectively along with seven biopsy-proven coeliacs. Serum samples were tested for anti-transglutaminase antibodies and anti-endomysium antibodies; positive samples were tested for coeliac-related human leucocyte antigen (HLA)-DQ2/8 and anti-viral antibodies. Purified anti-transglutaminase antibodies from the two study groups were tested for urea-dependent avidity, and their ability to induce cytoskeletal rearrangement and to modulate cell-cycle in Caco-2 cells, using phalloidin staining and bromodeoxyuridine incorporation assays, respectively. Nine of 222 children (4%) tested positive to anti-transglutaminase, one of whom also tested positive for anti-endomysium antibodies. This patient was positive for HLA-DQ2 and was diagnosed as coeliac following intestinal biopsy. Of the eight remaining children, two were positive for HLA-DQ8. Levels of anti-transglutaminase returned to normal in all subjects, despite a gluten-containing diet. Purified anti-transglutaminase of the two study groups induced actin rearrangements and cell-cycle progression. During an infectious disease, anti-transglutaminase antibodies can be produced temporarily and independently of gluten. The infection-triggered anti-transglutaminase antibodies have the same biological properties as that of the coeliacs, with the same in-vivo potential for damage.