Diagnostic validation of novel Borrelia antigens discovered by whole-proteome microarray: Advancing early detection and test of cure for Lyme disease

Lyme disease serodiagnosis has limited early sensitivity and cannot distinguish active from past infections. To address this, we screen a Borrelia afzelii whole-proteome microarray (1,296 proteins) using human (n = 149) and murine (n = 32) sera. We evaluate three early-stage antigens-BafPKo_A0001, BafPKo_D0016, and BafPKo_A0029. ELISA cutoffs are established using discovery cohort sera (n = 99) and validated with the validation (n = 242) and the prospective (n = 223) cohorts. A0001 demonstrates 87.8% sensitivity, outperforming C6 (69.4%) and STTT (22.5%) in the discovery cohort. In the validation cohort, A0001 reaches 90.5% sensitivity, surpassing C6 by 11.6% and STTT by 50%. In hyper-acute erythema migrans sera (from the prospective cohort), A0001 achieves 55.1% sensitivity, exceeding C6 and STTT by 14.6% and 33.3%, respectively. COMBO-3 and COMBO-2 yield the highest sensitivity of 92.9% and 66.1% in the validation and prospective cohort, respectively. A0001 and D0016 show enhanced and robust seroreversion after antibiotic treatment suggesting their potential as test of cure biomarkers in early Lyme disease.