2096. Associations with <i>Pneumocystis</i> Pneumonia in Solid Organ Transplant Recipients: Impact of Posttransplant Lymphoproliferative Disorder

Abstract Background Pneumocystis jirovecii pneumonia (PCP) is a potentially deadly infection afflicting the immunocompromised population, including solid organ transplant recipients. Several risk factors have been described, acute rejection, lymphopenia, and cytomegalovirus (CMV) infection. However, little known regarding imparted by posttransplant lymphoproliferative disorder (PTLD). Methods We performed nested case-control study of recipients diagnosed with PCP from 2000-2020. was defined as positive smear or polymerase chain reaction testing compatible clinical symptoms radiographic findings. Two control were matched to each case year first transplant, transplanted organ, sex. Each had at least much follow-up their date case’s diagnosis date. Multivariable conditional logistic regression analyze theorized factors. Results Sixty-seven cases met inclusion criteria 134 controls (Table 1). Median age 60.9 years, most common type kidney (52.2%). Fourteen patients history PTLD, 12 which developed PCP. All PTLD monomorphic, 6 EBV-positive, 9 receiving chemotherapy index date, only 1 patient prophylaxis. The median 85 days after diagnosis, while two more than earlier. After adjusting for age, rejection requiring treatment within last months, CMV current prophylaxis, lymphopenia (lymphocyte count &amp;lt; 0.5 x109/L) significant association (OR 14.0, 95% CI 1.7-114.5; p = .014). Lymphopenia also associated 8.2, 3.2-20.7; .001), other not. Table 1:Characteristics 67 Solid Organ Transplant Recipients Pneumonia Matched Controls Conclusion Diagnosis independently subsequent adjustment recognized This likely influenced PTLD-directed chemotherapy, particularly regimens containing rituximab. prophylaxis should be initiated in those undergoing active therapy, severe lymphopenia. Disclosures Authors: No reported disclosures.