Diagnostic Pitfalls in a Man with Systemic Lupus Erythematous

Area of Science:

• Immunology
• Rheumatology
• Infectious Disease Diagnostics

Background:

• Systemic lupus erythematosus (SLE) presents with diverse symptoms, often leading to diagnostic delays.
• A persistent Venereal Disease Research Laboratory (VDRD) positive reaction, even after prior syphilis treatment, can be a misleading diagnostic indicator.

Observation:

• A 32-year-old male presented with rash, weight loss, pancytopenia, and prolonged activated partial thromboplastin time (aPTT).
• He had a history of a persistent VDRL-positive reaction treated for syphilis five years prior.
• Antiphospholipid antibodies were detected, leading to an SLE diagnosis.

Findings:

• The persistent VDRL positivity was a false positive, masking an underlying SLE diagnosis.
• Delayed SLE diagnosis resulted in significant renal and cardiac complications.

Implications:

• VDRL testing for syphilis requires confirmation with other serological tests (e.g., TPHA, Western Blot) due to false positive potential.
• Spontaneous aPTT prolongation can be an indicator of antiphospholipid antibodies.
• Clinicians must integrate all clinical and laboratory data for accurate diagnosis, even with seemingly contradictory results.