Immunoblot and Polymerase Chain Reaction to Diagnose Ocular Syphilis and Neurosyphilis in HIV-positive and HIV-negative Patients.

Purpose: To evaluate immunoblot (IB) and polymerase chain reaction (PCR) to diagnose ocular- and neurosyphilis.

Methods

Prospective cross-sectional study. Aqueous humor (AH) and cerebrospinal fluid (CSF) samples were tested for treponemal DNA or antibodies to treponemal antigens.

Results

Thirteen of 106 cases had positive syphilis serology of which 69.2% were HIV+ (median CD4+ = 181 cells/µL). Four cases met CDC criteria for neurosyphilis (3 confirmed, 1 probable) and 2 additional cases required neurosyphilis treatment according to UpToDate algorithms. All AH and CSF samples tested PCR negative. Five cases were CSF IB+ and 3 cases AH IB+. Using our classification, eight patients had confirmed neurosyphilis, one had probable neurosyphilis, three had confirmed ocular syphilis and nine had probable ocular syphilis.

Conclusion

Our findings suggest that IB of AH and CSF provides additional evidence to diagnose ocular and neurosyphilis and allows us to classify them as probable or confirmed.