Transient serum anti-Scl70 antibodies and interstitial lung involvement in acute EBV infection

Among lymphotropic viruses, Epstein-Barr virus (EBV) is one of the most likely candidates for a pathogenetic role in some autoimmune rheumatic diseases by inducing a self-perpetuing activation of the immune system, in genetically predisposed individuals and is classically considered to induce systemic lupus erythematosus. Here, we describe the rare observation of transient clinico-serological alterations possibly triggered by acute EBV infection.Case report. A 13-years-old girl was referred to the Pediatric Division ofour hospital for hyperpyrexia (39 °C) and malaise. Standard chest x-ray showed a pulmonary infiltrate in the right lower lobe, followed by parenchymal consolidation, while serological tests revealed acute EBV infection with simultaneous infection by Mycoplasma pneumoniae. Diagnosis of EBV infection with bronchopneumonia was done. The patient was successfully treated with antibiotics and remained asymptomatic during the subsequent follow-up period.More recently, we retrospectively investigated the appearance of non-organ specific autoantibodies in the sera, stored at -80°C, from individuals with acute primary EBV infection, including the above patient. The analysis of her serum sample showed circulating anti-Scl70 antibodies (ELISA) and slight anti-SSB positiveness in Western Blot (WB). Past clinical history excluded any symptoms of connective tissue disease preceding EBV infection, whileclinico-serological re-evaluation 6 years later documented a moderate cold-induced acrocyanosis (started after the infectious event), serum anti-EBV IgG type, low titre of ANA (1:80, speckled), and disappearance of anti-ENA (ELISA and WB). Finally, nailfold videocapillaroscopy documented isolated neoangiogenetic phenomena, characterized by arborized capillary loops.Discussion. The diagnosis of“ EBV infection with bronchopneumonia and interstitial emphysema " was based on previous anecdotal reports on lung consolidation, characterized by interstitial infiltrate of mononuclear cells, usually observed in older individuals with ongoing EBV infection.The production of Anti-Scl70 antibodies is believed to be associated with a pathogenic process in SSc patients, since these autoantibodies are highly specific for SSc and are rarely detected in sera from individuals who do not have SSc or Raynaud’s phenomenon. In particular it is not clear whether anti–topo I antibody contribute to the pathogenesis of the disease or they should be regarded as simple epiphenomenon; however these antibodies are associated with pulmonary interstitial fibrosis and severe microvasculopathy. Studies have shown that anti–topo I antibody isotype levels are relatively stable during long-term observation in most patients, although a few patients experienced a prominent change in the antibody level.In another longitudinal analysis of autoantibody response to topoisomerase in systemic sclerosis japanese authors documented a distinct subset of anti-topo I-positive SSc patients who lose anti–topo I antibody during the disease course and have a favorable outcome.It is supposable that acute viral infection may be complicated by one or more clinical symptoms along with circulating specific autoantibodies, which may reproduce the early stage of well-defined connective tissue diseases. The transient alterations observed in the patient here described further underlined the role of different pathogenetic co-factors in the multistep process leading to chronic autoimmune disorders.