Serum and urine galactose deficient-IgA1 as alternative biomarkers in the management of IgA nephropathy.

INTRODUCTION: Immunoglobulin A (IgA) nephropathy (IgAN) results from abnormal accumulation of immune complexes containing galactose deficient IgA1 (Gd-IgA1) in the kidneys. About 40% of patients develop end-stage kidney disease within 20 years of renal biopsy. At present, the diagnosis and risk stratification of patients (using the international IgAN risk prediction tool) rely on renal biopsy, which is an invasive procedure. Also, treatment decisions are still dependent on proteinuria, which is not specific for IgA nephropathy. We discussed the role of serum and urine Gd- IgA1 in the diagnosis of IgAN, its association with disease progression and changes with treatment in patients with IgA nephropathy. MATERIALS AND METHODS: A systematic search of PubMed and Scopus databases was done to identify the articles that are relevant to the topic including systematic reviews and original articles. RESULTS: Several studies showed that both serum and urine Gd-IgA1 differentiate IgA nephropathy patients from healthy people and other glomerulonephropathies. Thus, it is useful as a less invasive diagnostic biomarker, although detection methods varied between studies with different sensitivities. There are various reports of its use as a prognostic parameter. Evidence is emerging for its use as a monitoring parameter for treatment. CONCLUSION: Galactose deficient IgA1 is a promising biomarker in the management of IgA nephropathy, although a more robust and standardised means of estimation is required.

Fatal persistence of West Nile virus subtype Kunjin in the brains of flavivirus resistant mice.

Flaviviruses cause febrile illnesses in humans that may progress to encephalitis and death. Both viral and host factors determine the level of virus replication and outcome of infection. In mice, genetically determined resistance conferred by the flavivirus resistance locus (Flv) is responsible for the restricted flavivirus replication and prevention of disease development. Majority of flaviviruses express significant virulence, replicate to high titers and cause high mortality in susceptible mice, while congenic resistant mice endure the infection, show significantly reduced levels of virus replication and remain healthy. In contrast, infection with West Nile virus subtype Kunjin (KUNV) causes morbidity and fatal outcomes even in mice that are naturally resistant to flaviviruses. There are two possible mechanisms that could account for such an unforeseen virulence of KUNV in resistant mice: (a) an abrogation of Flv-controlled natural resistance leading to high virus replication, or (b) massive virus-induced immunopathology in the brain. To identify the cause(s) of fatality of KUNV infection, disease progression, virus replication and brain histopathology were studied in parallel in resistant and congenic susceptible mice. While KUNV replicated to high titers causing early fatalities in susceptible mice, it showed only reduced replication associated with the delayed morbidity in resistant mice indicating no abrogation of the Flv resistance. No evidence of excessive immune cell infiltration and tissue damage following KUNV infection were found. However, incomplete KUNV clearance not previously described was perceived as an important source of pathogenesis in resistant mice.