Six-month risk of Pneumocystis pneumonia following acute cellular rejection: A case-control study in solid organ transplant recipients

Pneumocystis jirovecii in solid organ transplant recipients: updates in epidemiology, diagnosis, treatment, and prevention

PURPOSE OF REVIEW

This review highlights the epidemiology of Pneumocystis jirovecii pneumonia in solid organ transplant recipients, advancements in the diagnostic landscape, and updates in treatment and prevention.

RECENT FINDINGS

The increasing use of immune-depleting agents in the context of solid organ transplantation has given rise to P. jirovecii pneumonia in this population. The use of prophylaxis has dramatically reduced risk of infection; however, late-onset infections occur after cessation of prophylaxis and in the setting of lymphopenia, advancing patient age, acute allograft rejection, and cytomegalovirus infection. Diagnosis requires respiratory specimens, with PCR detection of Pneumocystis replacing traditional staining methods. Quantitative PCR may be a useful adjunct to differentiate between infection and colonization. Metagenomic next-generation sequencing is gaining attention as a noninvasive diagnostic tool. Trimethoprim-sulfamethoxazole remains the drug of choice for treatment and prevention of Pneumocystis pneumonia. Novel antifungal agents are under investigation.

SUMMARY

P. jirovecii is a fungal opportunistic pathogen that remains a cause of significant morbidity and mortality in solid organ transplant recipients. Early detection and timely treatment remain the pillars of management.

Clinical characteristics and risk factors for late-onset pneumocystis jirovecii pneumonia in kidney transplantation recipients

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a common and troublesome complication of kidney transplantation. In the era of prophylaxis, the peak incidence of PJP after kidney transplantation and specific characteristics of late-onset PJP have always been debated.

METHODS

We performed a retrospective study by analysing the data of post-transplantation pneumonia in adult kidney transplantation recipients between March 2014 and December 2021 in The Affiliated First Hospital of University of Science and Technology of China (USTC). A total of 361 patients were included and divided into early-onset PJP, late-onset PJP and non-PJP groups. The characteristics of each group and related risk factors for the late-onset patients were investigated.

RESULTS

Some patients developed PJP 9 months later with a second higher occurrence between month 10 and 15 after transplantation. Compared with non-PJP, ABO-incompatible and cytomegalovirus (CMV) viremia were significantly associated with late onset of PJP in multivariate analysis. The use of tacrolimus, CMV viremia, elevated CD8(+) T cell percent and hypoalbuminemia were risk factors for late PJP. Receiver operating characteristic curve analysis demonstrated that a combination of those factors could increase the sensitivity of prediction remarkably, with an area under the curve of 0.82, a sensitivity of 80% and a specificity of 83%.

CONCLUSIONS

PJP could occur months after kidney transplantation. ABO-incompatible transplant recipients are at high risk of PJP. In the later stages of transplantation, CMV viremia, T lymphocyte subsets percentage and serum albumin levels should be monitored in patients using tacrolimus.

Pneumocystis jiroveci Pneumonia: A Review of Management in Human Immunodeficiency Virus (HIV) and Non-HIV Immunocompromised Patients

Pneumocystis jirovecii pneumonia is an opportunistic fungal infection that was mainly associated with pneumonia in patients with advanced human immunodeficiency virus (HIV) disease. There has been a decline in Pneumocystis jirovecii pneumonia incidence in HIV since the introduction of antiretroviral medications. However, its incidence is increasing in non-HIV immunocompromised patients including those with solid organ transplantation, hematopoietic stem cell transplantation, solid organ tumors, autoimmune deficiencies, and primary immunodeficiency disorders. We aim to review and summarize the etiology, epidemiology, clinical presentation, diagnosis, and management of Pneumocystis jirovecii pneumonia in HIV, and non-HIV patients. HIV patients usually have mild-to-severe symptoms, while non-HIV patients present with a rapidly progressing disease. Induced sputum or bronchoalveolar lavage fluid can be used to make a definitive diagnosis of Pneumocystis jirovecii pneumonia. Trimethoprim-sulfamethoxazole is considered to be the first-line drug for treatment and has proven to be highly effective for Pneumocystis jirovecii pneumonia prophylaxis in both HIV and non-HIV patients. Pentamidine, atovaquone, clindamycin, and primaquine are used as second-line agents. While several diagnostic tests, treatments, and prophylactic regimes are available at our disposal, there is need for more research to prevent and manage this disease more effectively.

Prophylactic effect of low-dose trimethoprim-sulfamethoxazole for Pneumocystis jirovecii pneumonia in adult recipients of kidney transplantation: a real-world data study

OBJECTIVES

To evaluate the efficacy and safety of low-dose trimethoprim (TMP)-sulfamethoxazole (SMX) (TMP-SMX) as the primary prophylaxis for Pneumocystis jirovecii pneumonia (PJP) in adult recipients of kidney transplantation.

METHODS

Three kinds of prescriptions in kidney recipients were documented, including 20 mg TMP/100 mg SMX oral daily, 20 mg TMP/100 mg SMX oral every other day, and nonprophylaxis. The primary outcome was the incidence of PJP in the first 180 days of follow-up after kidney transplantation. The secondary outcomes were changes in renal and liver function.

RESULTS

Among the 1469 recipients, 1066 (72.56%) received 20 mg TMP/100 mg SMX daily, 127 (8.65%) received 20 mg TMP/100 mg SMX every other day, and 276 (18.79%) did not have prophylaxis prescription. The 276 recipients in the nonprophylaxis group had 124.92 person-years of follow-up, during which PJP occurred in 29 patients, for an incidence rate of 23.21 (95% confidence interval 15.76-32.72) per 100 person-years. The TMP-SMX daily group and the TMP-SMX every other day group had 524.89 and 62.07 person-years of follow-up, respectively, with no occurrence of PJP. There was no significant difference among the three groups in changes in renal and liver function (P >0.05, respectively). A total of 111 recipients in each group were enrolled in the propensity score matching analysis. It was revealed that the 111 nonprophylaxis recipients had 51.27 person-years of follow-up and 10 PJP cases. Prophylaxis was considered effective because there was a significant difference between the three groups (P <0.001).

CONCLUSION

Low-dose TMP-SMX prophylaxis significantly reduces the incidence of PJP within 6 months after kidney transplantation and has a favorable safety profile.

Pneumocystis jirovecii pneumonia in liver transplant recipients in an era of routine prophylaxis

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection in organ transplant recipients that may be prevented by antibiotic prophylaxis. We aimed to investigate the incidence rate (IR) of PCP and the related hospitalization and mortality rates in liver transplant recipients in an era of routine prophylaxis.

METHODS

We included all adult liver transplant recipients transplanted at Rigshospitalet between January 1, 2011 and October 1, 2019. Microbiology data were obtained from the Danish Microbiology Database (MiBa), a national database containing all data from all Departments of Clinical Microbiology in Denmark receiving samples from both hospitals and general practices. According to local guidelines, PCP prophylaxis was initiated 1 week posttransplantation and discontinued after 6 months or sooner in patients experiencing side effects.

RESULTS

We included 343 liver transplant recipients with 1153 person-years of follow-up (PYFU), of which 269 (78%) received PCP prophylaxis during the first 6 months posttransplantation. Seven (2%) recipients were diagnosed with PCP during follow-up. In the first 6 months posttransplantation and in 269 transplant recipients who received prophylaxis there were zero PCP events while the IR was 32 (95% confidence interval [CI] 2.9-148) per 1000 PYFU in 74 recipient who did not receive prophylaxis. During 7th to 12th month posttransplantation the IR was 20 (95% CI: 5.5-53) per 1000 PYFU. All seven (100%) recipients diagnosed with PCP were hospitalized, however none died.

CONCLUSIONS

PCP was not detected in liver transplant recipients while on prophylaxis. Though, it worth mentioning that two out of the seven PCP patients received high-dose prednisolone before the PCP event. All liver transplant recipients with PCP were hospitalized, but none died. Randomized clinical trials to determine the optimal duration of prophylaxis are warranted.