Paediatric apnoeas are not related to a specific respiratory virus, and parental reports predict hospitalisation.

AIM: The aim of this study was to determine the frequency of apnoeas in previously healthy young infants with acute respiratory tract infection (ARI) and correlate their occurrence with isolated micro-organisms, clinical findings, disease severity and outcome. METHODS: We performed reverse transcriptase real-time polymerase chain reaction (RT-PCR) on the nasal wash specimens of a prospective cohort study of 582 children with ARI. Clinical data on a subgroup of 241 infants under three months of age, with and without apnoeas, were compared. RESULTS: Our study found that 19 (7.9%) of the 241 infants under three months old had a history of apnoeas: eight had a respiratory syncytial virus (RSV), five had a different virus than RSV and seven RT-PCR results were negative. Infants with apnoeas were more likely to have cyanosis, had longer hospital stays and required extra oxygen for a longer period. Most patients with parental reported apnoeas also experienced apnoeas during hospitalisation. CONCLUSION: This study observed apnoeas irrespective of the isolated micro-organism, and we hypothesise that they were related to the pathophysiology of the respiratory infection and not to the micro-organism itself. Parental reported apnoeas were a major warning sign and predicted that apnoeas would occur in hospital.

Expression of the activation antigen CD97 and its ligand CD55 in rheumatoid synovial tissue.

OBJECTIVE: Fibroblast-like synoviocytes (FLS) express decay-accelerating factor (CD55) at high levels. Recently, it was found that CD55 is a specific cellular ligand for the 7-span transmembrane receptor CD97. The objective of this study was to define the expression of this receptor-ligand pair in synovial tissue (ST) to provide more insight into the interaction between FLS and surrounding cells. METHODS: Antibodies against CD97 and CD55 were used for immunohistologic analysis of synovial biopsy specimens from 16 patients with rheumatoid arthritis (RA) and 15 patients with osteoarthritis (OA). In addition, an enzyme-linked immunosorbent assay system was used to determine the expression of soluble CD97 (sCD97) in synovial fluid (SF) from 30 patients with RA, 13 with OA, and 10 with reactive arthritis (ReA). RESULTS: In both RA and OA ST sections, strong expression of CD55 was confirmed on FLS in the intimal lining layer, where it was also found that all macrophages expressed CD97. The percentage of macrophages that expressed CD97 was lower in the synovial sublining (P = 0.005). The mean levels of sCD97 in SF were significantly higher in RA patients than in patients with OA or ReA (P < 0.0001). CONCLUSION: These results suggest that FLS are able to interact with macrophages via the CD97/CD55 receptor-ligand system. In this respect, the CD97/CD55 pair may account for the specific architecture of the intimal lining layer and may be of primary importance in maintaining and amplifying synovial inflammation. The specific increase in sCD97 levels in RA SF might be related to the presence of activated proteolytic systems or to the increase in synovial mass, rather than a consequence of local receptor-ligand interaction.