MADRID – The benefits of primary prophylaxis for pneumocystis pneumonia (PCP) outweighed the risks of treatment in patients taking prolonged, high-dose corticosteroids for various rheumatic diseases in a study presented at the European Congress of Rheumatology.
In a single-center, retrospective cohort study of 1,522 corticosteroid treatment episodes in 1,092 patients with a variety of rheumatic conditions given over a 12-year follow-up period, the estimated incidence of PCP was 2.37 per 100 person-years.
Significantly fewer cases of PCP occurred at 1 year, however, in the 262 patients who were cotreated with the antibiotic combination of trimethoprim and sulfamethoxazole (TMP-SMX), than in the 1,260 patients who received no such antibiotic prophylaxis in addition to their steroid therapy.
The adjusted hazard ratio (HR) for no PCP at 1 year of follow-up in the prophylaxis group, versus the no prophylaxis group, was 0.096 (P = .022).
The TMP-SMX combination also significantly reduced the mortality associated with PCP, with an adjusted HR of 0.09, versus no prophylaxis (P = .023).
“Pneumocystis pneumonia is a major opportunistic infection in immunocompromised patients associated with high morbidity and mortality,” explained the presenting study investigator Jun Won Park, MD, of Seoul National University Hospital in the Republic of Korea.
Dr. Park added that corticosteroid therapy was an important risk factor for PCP but that the risk-benefit ratio had not been evaluated sufficiently in patients with rheumatic diseases and that there was “different opinion among rheumatologists regarding [the value of] PCP prophylaxis.”
The current study aimed to see if primary antibiotic prophylaxis could prevent PCP in patients with rheumatic diseases, which included patients with systemic lupus erythematosus (SLE), dermatomyositis, rheumatoid arthritis, and Behçet’s disease.
For inclusion, patients had to have been treated with prednisolone at a dose of 30 mg/day or more (or its equivalent) for at least 4 weeks and observed for 1 year. Patients with a prior history of PCP or conditions associated with this opportunistic infection, such as HIV, cancer, or solid organ or hematopoietic stem cell transplantation, were excluded.
Dr. Park reported that PCP prophylaxis was given at the discretion of the treating physician, and the mean duration of TMP-SMX was 230 days.
In the prophylaxis group, 34 adverse drug reactions occurred. Two of these reactions were serious – one case of pancytopenia and one case of Steven’s Johnson syndrome – but both resolved after the antibiotic treatment was discontinued.
A sensitivity analysis was performed, giving consistent results, and a risk-benefit analysis showed that the number needed to treat to prevent one case of PCP was 52, considering all rheumatic disease studied, while the number needed to cause one serious adverse drug reaction was 131.
Taken together, these results suggest a role for TMP-SMX as primary prophylaxis for PCP in patients with rheumatic diseases who need prolonged treatment with high-dose corticosteroids, Dr. Park said.
Dr. Park reported having no relevant financial disclosures.