A 75 year old man presents to hospital with a cerebro-vascular accident.

As part of his routine laboratory investigations syphilis serology is performed.

The results show a positive TPPA titre of 1:128. RPR testing is negative.

Question 1: Could this TPPA result be falsely positive?

Question 2: What clinical scenarios could give rise to this serological picture?

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TPPA: Treponema pallidum Particle Agglutination assay

RPR: Rapid Plasma Reagin assay