The patient whose prostate-specific antigen (PSA) level went from 6.1 ng/mL to 4.76 after two weeks of antibiotic therapy (Item 98-11) now has a PSA of 2.89, despite the fact that he received no additional antibiotics. (The absence of cancer was confirmed by a negative biopsy; prostatitis was postulated but never formally diagnosed.) He takes supplementary calcium and activated vitamin D for hypoparathyroidism, and his calcium level has risen (from 7.5 mg/dL to 9.0). Vitamin D levels are still low to low-normal, and his parathyroid hormone is low but detectable. The endocrinologist notes that the hypoparathyroidism may not be lifelong and has advised not taking more than 1,500-1,800 mg of calcium daily. (The patient has taken as much as 2,100-2,400 mg calcium per day during the three to four months when he was not taking the activated form of vitamin D.) Since hypoparathyroid patients on calcium supplementation are known to be at risk for urinary tract stones if their calcium goes too high (>8.0-8.5 mg/dL), could prostate inflammation have caused the elevated PSA? Could the original episode have been subclinical prostatitis?
—Jeffrey W. Glassheim, DO, Oshkosh, Wis.
To answer the last question first—yes, asymptomatic prostatitis exists and can raise the PSA, but as was previously noted, the key to that diagnosis is the evaluation of post-prostatic massage fluid revealing >20 WBCs/high-power field. Some patients, as they pass stones through the distal ureter, will complain of urgency and frequency. It might be logical to suppose, then, that such a process could irritate the prostate and cause a false-positive elevation in PSA. In a completely asymptomatic patient, however, it would be difficult to correlate tiny stone passage with prostatic inflammation.
—David T. Noyes, MD (99-18)