We describe a rare case of a nephrotic syndrome (NS) as a complication of secondary syphilis (SS), which resolved with appropriate treatment of the infection. This is a 54 year-old male with no pertinent medical history, who presented to clinic with bilateral palmar rash. He was diagnosed of secondary syphilis with positive Venereal Disease Research Laboratory test (VDRL) at 1:128 dilution as well as a strongly positive Fluorescent Treponemal Antibody (FTA) test. He was treated with benzathine penicillin 2.400.000 IU. Four days later, he developed fevers, chills, malaise, swelling, generalized arthralgia and myalgia and decided to seek medical attention in the emergency department. Initially, his constitutional symptoms were thought to be a Jarish-Herxheimer reaction following antibiotic initiation in a treponemal infection. However, he also had acute onset of abdominal ascites, obvious anasarca, and polyuria, which prompted an additional investigative work up.
Labs revealed hyperlipidemia, hypoproteinemia with albumin of 2.7 g/dL, moderately elevated liver enzymes and normal renal function with creatinine 1.0 mg/dL. Urinalysis showed microscopic hematuria with dystrophic red blood cells, and +4 proteinuria. He had a diagnostic paracentesis for ascitic fluid analysis that was consistent with a transudative process with a serum to ascitic albumin gradient of 1.8. HIV, Hepatitis B and C screenings were negative and echocardiogram was unremarkable. 24-hour urine collection demonstrated protein excretion of 9 grams over 24 hours, which confirmed glomerulonephritis with nephrotic syndrome.
This patient’s NS was a sequela of SS. A proposed mechanism of NS in a patient with SS is that the circulating antitreponemal antigen-antibody immune complexes settle onto the glomerular basement membrane which initiates an inflammatory process that eventually leads to organ failure. This phenomenon can be appreciated on immunofluorescence of renal biopsy as it would show subepithelial dense deposition of immune complexes.
The hypoalbuminic state leads to a decreased intravascular oncotic pressure, which eventually progresses to anasarca and ascites. However, these complications are readily reversible with appropriate penicillin therapy against the syphilitic spirochete. At one month follow up, our patient was noted to have significant improvement in his condition. His ascites resolved, repeat albumin/protein ratio was 1 gram over 24 hours, and his VDRL titers down trended to 1:64.
Since glomerulonephritis can be a devastating disease that often requires treatment with toxic agents: therefore it is important to have syphilis in the differential diagnosis, as it is readily reversible with just one dose of penicillin. A thorough history and physical can even circumvent invasive testing such as a renal biopsy which is often necessary in severe nephropathy. With the worldwide resurgence of syphilis, one must be aware of the correlation between the treponemal infection and glomerulonephritis.