Background/Purpose:

The risk-benefit of Pneumocystis jiroveci pneumonia (PCP) prophylaxis in systemic lupus erythematosus (SLE) is not well defined and there are no SLE-specific guidelines. On the one hand, the risk of PCP is relatively low.^1,2 On the other hand, high frequency of trimethoprim-sulfamethoxazole (TMP-SMX) related adverse effects have been reported.³ Prophylaxis initiation is highly variable among providers, based on 2008 survey data.⁴ As a result, it is unknown whether the decision to initiate PCP prophylaxis is guided by patient-specific characteristics. Therefore, the objective of this study was to ascertain the rates of PCP prophylaxis and factors associated with prophylaxis initiation among SLE patients receiving immunosuppression.

Methods:  

Using electronic medical record, we identified new SLE as having: 1) ≥2 SLE ICD codes within 1-6 months of each other between 1/1/2006 and 12/31/2017, 2) no visits with SLE codes or SLE-related prescriptions within one year prior, and 3) ≥1 immunosuppressive prescriptions after the first SLE visit. Records of patients with the word “pneumocystis” were reviewed to identify PCP cases. Patient-specific characteristics were compared between patients who had received a prescription for PCP prophylaxis (TMP-SMX, atovaquone, or dapsone) within 14 days of starting immunosuppression (besides corticosteroids), and those who did not.

Results:

Of the 693 patients who met inclusion criteria, there was 1 confirmed (by quantitative PCR in bronchoalveolar lavage) and 1 probable PCP case; 111(16%) were started on PCP prophylaxis (Table). Compared to patients not on prophylaxis, patients on PCP prophylaxis had a higher frequency of renal disease (15% vs. 7%, p=0.002) and congestive heart failure (5% vs. 2%, p=0.04).  They were more likely to be on hydroxychloroquine (70% vs. 48%, p<0.001), and had a longer median duration between the first SLE visit and initiation of immunosuppression (3.5 vs. 11.5 months, p<0.001). There were no differences between groups in patient demographics, comorbidities, or cell counts at SLE onset.

Conclusion:

Over a 12-year period at our tertiary care center, the use of PCP prophylaxis in SLE patients on immunosuppression was relatively low (16%), and the incidence of PCP among patients not on prophylaxis was rare (0.34%).  Prophylaxis was significantly more likely to be initiated in SLE patients with cardiac or renal disease. Additional secondary analyses of duration and choice of PCP prophylaxis, as well as compliance and adverse effects that could have affected the number of patients on prophylaxis are ongoing. These results will guide establishment of evidence-based guidelines on the use of PCP prophylaxis for SLE patients.

References: 1. Feldman CH et al., A&R 2015; 67: 1577–1585. 2. Kapoor TM, et al Lupus. 2017 Dec;26(14):1473-1482. 3. Petri M et al., J Rheum 1992; 19: 265–269. 4. Gupta D et al, J Clin Rheum 2008; 14: 267–272.