No abstract

To improve IgG antibody detection in the serodiagnosis of Borrelia burgdorferi infection, indirect enzyme-linked immunosorbent assays (ELISAs) were developed utilizing purified recombinant antigens of B. burgdorferi sensu lato: the chromosomally encoded proteins p100 of strain PKo (B. afzelii) and p4li (internal flagellin fragments) derived from strains PKo, PBi (B. garinii), and B31 (B. burgdorferi sensu stricto). In Western blot analysis, these proteins have proved to be highly specific and sensitive for IgG antibody detection, especially in late manifestations of Lyme borreliosis. Sera from 464 forest workers, a high-risk group for infections with B. burgdorferi, were investigated and the results compared with those obtained by a commercial ELISA using an octyl-beta-D-glucopyranoside (OGP) extract from B. afzelii (PKo) cells as the antigenic substrate. Sera derived from 200 blood donors served for determination of the 95% specific cut-off level. The number of positive test results using OGP-ELISA (23.9%) was only slightly higher than that using p100-ELISA (19.8%); corresponding results were observed in 84.7% of all sera (14.2% positive, 70.5% negative). The frequency and interassay correspondence of positive results increased with the age of the forest workers, as most markedly demonstrated by p100 and OGP assays (P < 0.0001). Using the p41i-ELISAs, generally no significant strain-dependent differences in sensitivity were found (PKo, 13.8%; PBi, 14.2%; B31, 12.9%). Compared with the p100-ELISA, the p41i-assays showed significantly lower detection rates for IgG antibodies (P < 0.03) and a reduced capacity for quantitative discrimination between seropositive individuals and negative controls (P < 0.0007). At a 95% specificity, the IgG antibody detection rate could be increased to 23.1% when the p100-ELISA was evaluated in combination with the assays using p41i/PBi and P41i/B31. Due to its high sensitivity, the specific recombinant p100-ELISA might be a suitable test for detection of late immune responses to B. burgdorferi, thus being especially useful for epidemiological investigations.

Erythema migrans borreliosis, the European equivalent of Lyme borreliosis, is endemic in Bavaria, situated in the Southeast of West Germany. It seems of particular interest to what extent a population group especially prone to tick bites by its occupation shows clinical and serological hints to an infection with Borrelia burgdorferi (Bb). In 1983 we examined 2 11 forest workers from different regions of Upper Bavaria clinically and tested their sera with regard to antibodies (Ab) against Bb by means of an indirect immunofluorescence assay.' Two and a half years (y) later 53 of initially 71 seropositive forest workers could be reexamined. The clinical course was determined utilizing a standard questionnaire and further clinical data applied by family doctors. Serum Ab titers were reevaluated; additionally syphilis serology was performed, and rheumatoid factors, antinuclear antibodies, and HLA phenotypes determined. Of the collective initially examined ( n = 21 1; age 17-68, median 49 y), 71 (33.6%) proved to be seropositive (reciprocal IgM and/or IgG titers 2 10). The percentage of seropositivity increased with rising age (median age of 7 1 seropositives 56 y, of 140 seronegatives 46.5).' IgG Ab were found in 84.5%, IgM Ab in 53%, IgG and IgM Ab in 38% of the 7 1 sera. Slight differences between seronegative and seropositive forest workers turned out in tick bite history (never bitten by tick 25% of the seronegatives, 10% of the seropositives; p = 0.01, Fisher's exact test), elevated erythrocyte sedimentation rates (7% in seronegatives vs. 16% in seropositives), in heart symptoms such as arrythmia, tachycardia, dycardia as well as in verified cardiac disease (9% in seronegatives vs. 14% in seropositives), manifest joint involvement (22% vs. 23.6%), nervous system disorders (6% vs. 7%) and in history of erythema migrans (0.7% vs. 2.8%). No actual cutaneous manifestations of erythema migrans borreliosis were observed in the initial collective. uThis investigation was in part supported by a grant (no. Ne 329/1-1) from Deutsche Forschungsgemeinschaft. 416

The frequencies of HLA A, B, C and DR antigens were evaluated in 220 persons from West Germany with inapparent and manifest Borrelia burgdorferi infections. Thirty-seven forest workers showing elevated antibody titres against Borrelia burgdorferi had asymptomatic infection, and are described as stage 0. One hundred and eighty-three patients presented with the clinical stages 1-3 of the infection. Control persons (n = 655) were typed in the same time period and by identical staff. HLA CW3 was present in 36.3% of patients as compared to 23.2% of the controls (RR = 1.88, pcorr = 0.03) and was significantly associated with manifest infection. In addition, the antigen A2 was found slightly but not significantly more frequent in the patients (55.2% vs 44%; pcorr = 0.41). The phenotype combination HLA A2 and Cw3, however, was significantly elevated in patients (24.6% vs 10.8%; pcorr = 0.0005). In contrast to these class 1 antigens, HLA DR3 showed a tendency of negative association with manifest infection. But this finding was not yet found to be significant (15.3% vs 25.3%; RR = 0.53, pcorr = 0.26). The frequency of HLA DR2 showed a constant decrease from stage 0 to stage 3 (inapparent infection to late complications). Using the rank correlation coefficient of Spearman, this association was found to be significant (-1.00, p less than or equal to 0.05). All other tested HLA antigens and antigen combinations showed no significant differences. The data suggest that HLA CW3 may be associated with Borrelia burgdorferi infection, whereas HLA DR2 and DR3 may be associated with less incidence of severe courses and less complications in this disorder.

Erythema migrans borreliosis is a complex multisystemic infectious disorder caused by the spirochetal species termed Borrelia burgdorferi. The clinical picture is characterized by affection of various organ systems such as skin, central and peripheral nervous system, heart, joints, and some other organs. Reports on HLA association to Borrelia burgdorferi infection (BBI) are still controversial. HLA-DR2 was found to be correlated to more severe and/or chronic courses of this infectious disorder.'** However, this finding was not confirmed by other^.^ The purpose of this study was to