GENETIC SUSCEPTIBILITY TO SEVERE COURSE OF NEPHROPATHIA-EPIDEMICA CAUSED BY PUUMALA-HANTAVIRUS

Nephropathia epidemica (NE) caused by Puumala hantavirus is one type o f hemorrhagic fever with renal syndrome (HFRS). There is considerable variability in the clinical severity of NE. Many infections are subcli nical but the disease can even be fatal. We questioned whether the wid e spectrum in the outcome of NE is dependent on host-related immunolog ical factors by determining the major histocompatibility complex marke rs (MHC) in 74 adult patients with NE. Patients with the most severe c ourse of the disease had a very high frequency of HLA B8, C4AQ0, and DRB10301 alleles. HLA B8 was found in all 7 (100%) patients with shoc k and in 9 of the 13 (69%) patients who required dialysis, versus in o nly 25 of 74 (34%) in the entire population, and in 14 of 93 (15%) con trols. In addition, various other clinical findings pointing to a seve re form of NE were found to be associated with these alleles. Interest ingly, the same MHC alleles are risk factors for various autoimmune di seases. This is the first study where a certain HLA haplotype is found to be associated with the clinical course of an acute viral disease o r acute nephritis.