Do antibody-coated bacteria prove bacterial prostatitis?

A proposal of subcategorization of bacterial prostatitis: NIH category I and II diseases can be further subcategorized on analysis by therapeutic and immunological procedures

AIM

We propose preliminarily that acute (category I of the NIH consensus definition) and chronic prostatitis (category II) can be subcategorized into primary and recurrent diseases based on the precise analysis of the clinical course and the immunological parameters in prostatic secretions of our cases.

METHODS

Five patients with stone-free, acute febrile prostatitis and nine patients with acute episodes of afebrile urinary infection were included. The expressed prostatic secretions (EPS) were collected soon after the acute illnesses subsided after medication administration and they were examined microscopically, bacteriologically, and serologically. First-line medications were cefem antibiotics with conventional doses for febrile cases and low doses for afebrile cases. They were administered for at least 2 weeks. Second-line conventional medication with sulfamethoxazole-trimethoprim or levofloxacin was given only to the patients in whom remaining prostatic infections were revealed.

RESULTS

The first-line medications were successful in all patients and they promptly became asymptomatic in 1 week. All the EPS were infected except for two afebrile cases. Prostatic infections were eradicated by second-line conventional medications. In a patient with afebrile prostatitis whose EPS were free of macrophages and immunoglobulin (Ig)M, the eradication of prostatic pathogens was achieved without second-line antibacterial medication.

CONCLUSIONS

Bacterial prostatitis could be classified into primary and recurrent chronic infections in each of the febrile (category I) and afebrile (category II) illnesses. A cefem regimen in varying doses was a clue for differential diagnosis as it did not affect the pathogens in the prostatic ducts or acini unless heavy urine reflux occurred in the ductal draining systems. Macrophages and immunoglobulins, especially IgM, in the EPS were useful immunological parameters to differentiate primary and recurrent infections of the prostate. Fluoroquinolones or sulfamethoxazole-trimethoprim should not be employed in acute urinary infections in male patients until the confirmation of prostatic infection to avoid injudicious use of them, which might cause an increasing prevalence of resistant uropathogens in the community. The evacuation of the prostate by repetitive massage seemed to be effective to enhance the prompt eradication of pathogens from the prostatic tissue and to keep patients asymptomatic throughout the course of the disease by preventing tissue pressure elevation.

Opsonophagocytosis in infected urine: relation to pH and osmolality

Polymorphonuclear neutrophils (PMN) in freshly voided urines from 20 symptomatic bacteriuric patients were examined. Although the PMN were viable (median 85%), in only 2 cases could phagocytosis of the infecting organisms be demonstrated, even after the addition of serum opsonins. Polymorphonuclear neutrophils from urines of 12 patients were also unable to phagocytose added opsonized Staphylococcus aureus. These urines were found to be of pH < 6.0 and/or osmolality > 700, or < 180 mOsm. However, the phagocytic function of these PMN was restored when transferred to Hanks balanced salt solution (HBSS). By contrast, most PMN in urines of suitable pH (> or = 6.0) and osmolality (between 200 to 700 mOsm.) phagocytosed the opsonized S. aureus. When bacteria cultured from the infected urine were incubated in the same urine and then transferred to HBSS, in 17 of 19 cases opsonization occurred and the organisms were phagocytosed when PMN, isolated from blood, were added. IgG appeared to be the prime opsonin in the urines, and heat-stable opsonins for S. aureus were also present. It is concluded that lack of opsonization is not a major cause of the absence of phagocytosis by urinary PMN. Low pH and adverse osmolality are largely responsible, correction of which may restore PMN function in vivo.