Urinary ß2-microglobulin as an early marker of infantile enterovirus and human parechovirus infections.

Enterovirus and human parechovirus (HPeV) are RNA viruses belonging to the family Picornaviridae that frequently infect infants. These infections show a wide variety of clinical manifestations, from mild to severe. However, there are no known early clinical markers for diagnosis and prediction of disease severity. The aim of this study was to examine the clinical utility of urinary beta 2-microglobulin (ß2MG) for the early detection and prognosis of infantile enterovirus and HPeV infections.This retrospective study included 108 full-term infants younger than 60 days of age, including 15 with enterovirus or HPeV-3 (enterovirus/HPeV-3), 22 with respiratory syncytial virus (RSV), and 24 with bacterial infections. Laboratory data and clinical characteristics were compared among these 3 groups. Of the 15 patients with enterovirus/HPeV-3, 6 were treated with intravenous immunoglobulin (IVIG subgroup) because of severe clinical conditions.Urinary ß2MG to creatinine ratio (ß2MG/Cr) was significantly higher in the enterovirus/HPeV-3 group compared to bacterial and RSV infection groups (both P < .001). In the enterovirus/HPeV-3 group, mean peak urinary ß2MG/Cr was observed on day 1 or 2. Urinary ß2MG/Cr values were significantly higher in the IVIG subgroup than the non-IVIG subgroup (P < .001).Increased urinary ß2MG/Cr in early-stage infection may be a useful clinical marker for the detection and prediction of infantile enterovirus and HPeV infection severity.

Marked elevation of urinary ß2-microglobulin in patients with reversible splenial lesions: A small case series.

The magnetic resonance imaging findings of reversible isolated lesions with transiently reduced diffusion in the splenium of corpus callosum of patients with a wide spectrum of pathological conditions are referred to as reversible splenial lesion syndrome (RESLES). Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is probably included within the spectrum of RESLES; however, its exact pathophysiology is not known. Here, we describe three patients with MERS and one patient with RESLES, all of whom showed elevated urinary ß2-microglobulin regardless of diagnosis and presence of pathogens. Elevated urinary ß2-microglobulin suggested that an excessive immune response might play a role in the pathophysiology of reversible splenial lesions.