ENZYME-LINKED IMMUNOSORBENT ASSAYS WITH RECOMBINANT INTERNAL FLAGELLIN FRAGMENTS DERIVED FROM DIFFERENT SPECIES OF BORRELIA-BURGDORFERI SENSU LATE FOR THE SERODIAGNOSIS OF LYME NEUROBORRELIOSIS

The serodiagnosis of early Lyme neuroborreliosis is hampered by false negative results and one of the reasons could be the heterogeneity of strains of Borrelia burgdorferi sensu late. For this study IgG enzyme- linked immunosorbent assays (ELISAs) with recombinant internal flagell in fragments (p41/i; amino acids 129-251) derived from strains PKo (B. afzelii), B31 (B. burgdorferi sensu stricto), and PBi (B. garinii) an d ELISAs with whole-cell detergent extracts of strains PKo, PKa2 (B. b urgdorferi sensu stricto), and PBi were compared. Cut off absorbance v alues were defined by the 94th and 92th percentiles of 200 sera from b lood donors. Sera from patients with clinically defined neuroborrelios is [n=88; 41 culture proven and 47 intentionally selected by the crite ria specific IgG cerebrospinal fluid/serum index greater than or equal to 2 and a serum IgG immunofluorescence assay value of <1:64] were te sted. The sensitivities of the three whole-cell detergent-extract ELIS As were similar (46.6-49.2%), whereas those of the recombinant ELISAs were highest with p41/i:PBi (57.1%) and lowest with p41/i:PKo (21.5%). A combination of the p41/i:PBi and the p41/i:B31 test was most sensit ive (59.8%). The correlation of absorbance values of different assays was very high for the three whole-cell detergent-extract ELISAs, where as the absorbance values obtained with the three recombinant tests dif fered considerably. The greatest differences were observed between p41 /i:PKo and any of the other two recombinant antigens. The differences in immune reactivity of patients sera (due to strain heterogeneity?) s eems to have more influence on the results of an assay based on a sing le antigen than on a whole-cell-based test.