PCP was mostly a late-onset disease occurring after complete course of prophylaxis particularly among patients with CMV infection or allograft rejection. PCP is associated with significant allograft loss. Extended prophylaxis targeting recipients with allograft rejection or CMV infection may reduce the risk of PCP.

Strongyloides stercoralis hyperinfection in an immunocompromised host has a high mortality rate but may initially present with non-specific pulmonary and gastrointestinal symptoms. Donor-derived S. stercoralis by kidney transplantation is an uncommon diagnosis and difficult to prove. We report two renal allograft recipients on different immunosuppressive maintenance regimens that developed strongyloidiasis after transplantation from the same donor. Recipient 1 presented with a small bowel obstruction. Larvae were demonstrated on a duodenal biopsy and isolated from gastric, pulmonary, and stool samples. Serologic testing for S. stercoralis was negative at a referral laboratory but positive at the Centers for Disease Control. The patient's hospital course was complicated by a hyperinfection syndrome requiring subcutaneous ivermectin due to malabsorption. Recipient 1 survived but the allograft failed. Recipient 2 had larvae detected in stool samples after complaints of diarrhea and was treated. On retrospective testing for S. stercoralis, pre-transplant serum collected from the donor and Recipient 1 was positive and negative, respectively. Donor-derived strongyloidiasis by renal transplantation is a preventable disease that may be affected by the immunosuppressive maintenance regimen. Subcutaneous ivermectin is an option in the setting of malabsorption. Finally, routine screening for S. stercoralis infection in donors from endemic areas may prevent future complications.

No abstract

Background In solid organ transplant (SOT) recipients, the primary vaccination series against COVID-19 is three doses followed by boosters. We determined whether a fourth dose booster induced Omicron BA.4/5 neutralizing antibodies and T-cells in a large multicenter cohort study. Methods Serum was collected 4-6 weeks post third and fourth dose of mRNA vaccine in 222 SOT recipients. Neutralizing antibodies (nAb) were measured using a pseudovirus neutralization assay targeting the Omicron BA.4/5 spike protein. A subset underwent T-cell testing. Results Median age of the cohort was 63 years (IQR 50-68) with 61.7% men. BA.4/5 nAb detection increased from 26.6%(59/222) post third dose to 53.6%(119/222) post fourth dose (p<0.0001). In patients with breakthrough infection prior to fourth dose (n=27), nAb were detected in 77.8% and median nAb titers were significantly higher compared to those with four vaccine doses alone (p<0.0001). Factors associated with a low BA.4/5 neutralization response after fourth dose were older age (OR 0.96, 95%CI 0.94-0.99), mycophenolate use (OR 0.39, 95%CI 0.20-0.77) and prednisone use (OR 0.34, 95%CI 0.18-0.63), and vaccine type (OR 0.72, 95%CI 0.51-0.99) while breakthrough infection prior to fourth dose (OR 3.6, 95%CI 1.3-9.9) was associated with a greater nAb response. Polyfunctional BA.4/5-specific CD4+ T-cells significantly increased after four doses and were identified in 76.9% of patients at a median frequency of 213 per 106 cells (IQR 98-650). Conclusion In summary, a booster significantly increases BA.4/5-specific neutralization and polyfunctional CD4+ T-cell responses, suggesting protection from severe disease even with new Omicron variants. However, SOT recipients that are older, on mycophenolate and prednisone need further preventative strategies.

No abstract