Nephrotic-Range Proteinuria in Patient with Syphilis and HIV

Introduction: Syphilis is a curable sexually transmitted infection caused by Treponema Pallidum. Infection develops in stages (primary, secondary, latent and tertiary), each associated with different signs and symptoms. Kidney manifestations are rare but can be a feature of secondary syphilis. Membranous nephropathy is most commonly observed; syphilis associated kidney disease can also present as nephrotic syndrome, acute kidney injury, membranoproliferative glomerulonephritis, or interstitial nephritis. Case Description: 34 year old male with newly diagnosed human immunodeficiency virus (HIV), history of gonorrhea, and recent positive syphilis screen (RPR 1:512) presented with bilateral vision loss. He underwent lumbar puncture and was diagnosed with secondary syphilis with ocular/CNS involvement (CSF VDRL 1:16). Treatment with IV penicillin was initiated. His kidney function was normal but a routine urinalysis (UA) was positive for proteinuria. Repeat UA confirmed the presence of albuminuria and was also notable for 8 RBC/hpf. Urine protein creatinine ratio was 4.1 g/g. Serum albumin was normal at 4.0g/dL. His physical examination was notable for improving rashes and no peripheral edema. Further infectious testing was notable for HIV viral load 65,897 copies/mL and CD4 count 171 cells/uL. Hepatitis B surface antigen and hepatitis C antibody were negative. Further workup for nephrotic syndrome was initiated: complement levels were normal, ANA negative, kappa:lambda ratio normal and no monoclonal spike on SPEP or UPEP. Renal biopsy was pursued which showed marked subepithelial deposits along with numerous tubuloreticular structures consistent with membranous glomerulopathy. Immunofluorescence positive for IgG, IgA, IgM, and C3. C1q was negative. Discussion: Syphilis is re-emerging in the US - in 2022, the highest number of cases of syphilis were reported since 1950 with an increase of 17.3% since 2021. Most cases reported were primary or secondary syphilis. Individuals who present with proteinuria should be screened for syphilis. Although membranous nephropathy has also been reported in HIV, it seemed most likely that this patient’s membranous nephropathy was related to syphilis. Proteinuria usually resolves with treatment of syphilis. Our patient was unfortunately lost to follow up so it is unknown if his proteinuria improved following treatment.