Risk factors for Pneumocystis jiroveci pneumonia (PcP) in renal transplant recipients

Colonization by Pneumocystis jirovecii and its role in disease

Although the incidence of Pneumocystis pneumonia (PCP) has decreased since the introduction of combination antiretroviral therapy, it remains an important cause of disease in both HIV-infected and non-HIV-infected immunosuppressed populations. The epidemiology of PCP has shifted over the course of the HIV epidemic both from changes in HIV and PCP treatment and prevention and from changes in critical care medicine. Although less common in non-HIV-infected immunosuppressed patients, PCP is now more frequently seen due to the increasing numbers of organ transplants and development of novel immunotherapies. New diagnostic and treatment modalities are under investigation. The immune response is critical in preventing this disease but also results in lung damage, and future work may offer potential areas for vaccine development or immunomodulatory therapy. Colonization with Pneumocystis is an area of increasing clinical and research interest and may be important in development of lung diseases such as chronic obstructive pulmonary disease. In this review, we discuss current clinical and research topics in the study of Pneumocystis and highlight areas for future research.

Aggressive immunosuppressant reduction and long-term rejection risk in renal transplant recipients with Pneumocystis jiroveci pneumonia

OBJECTIVES

Pneumocystis jiroveci pneumonia is a rare but lethal complication in renal transplant recipients. Dose reduction of immunosuppressive agents in such situations is recommended, but its quantity and safety are unclear.

MATERIALS AND METHODS

From January 2001 to January 2011, twenty of one thousand forty-six renal transplant recipients in a single center developed Pneumocystis jiroveci pneumonia, which was diagnosed by the Giemsa and Gomori methenamine silver stains from a specimen of bronchoalveolar lavage.

RESULTS

We found that timing of the first immunosuppressant reduction of the Pneumocystis jiroveci pneumonia survivor (mean, 1.4 days after admission) was significantly earlier than that of the deceased patient (mean, 5.1 days after admission). Logistic regression analysis indicated that for those whose immunosuppressants were reduced more aggressively (either 1 of the immunosuppressants was reduced by more than 50% within 2 days of hospitalization) were significantly more likely to survive (mortality risk, OR, 0.074 [95% CI, 0.01-0.84]; P = .035). In addition, none of the survivors developed acute rejection or allograft necrosis during a mean follow-up of 2 years.

CONCLUSIONS

Dosage reduction of immunosuppressive agents in renal transplant recipients with Pneumocystis jiroveci pneumonia should be prompt and sufficient. Aggressive immuno-suppressant dosage reduction is safe in such circumstance and is associated with minimal risk of in-hospital and long-term acute allograft rejection.

Pneumocystis jirovecii pneumonia in non-HIV-infected patients: new risks and diagnostic tools

PURPOSE OF REVIEW

Non-HIV-infected populations are increasingly identified as being at risk for developing Pneumocystis jirovecii pneumonia (PJP). These patients typically present with severe disease and poorly tolerate invasive diagnostic procedures. This review examines recently reported risks for PJP in non-HIV populations and summarizes new diagnostic techniques.

RECENT FINDINGS

PJP is associated with immunomodulatory drug therapies, including monoclonal antibody therapies such as tumour necrosis factor α antagonists, and calcineurin inhibitors. Underlying disease states include solid-organ transplantation, connective tissue and rheumatologic disorders, inflammatory bowel disease, haematological malignancies, and solid tumours. Modern diagnostic techniques [conventional PCR, quantitative PCR, (1→3)-β-D-glucan assays, and PET] are reviewed with respect to predictive value and clinical utility. In particular, current literature regarding validation and specificity of molecular diagnostic techniques is summarized, including application to minimally invasive specimens.

SUMMARY

HIV-negative populations at risk for PJP can be identified. Conventional PCR increases diagnostic sensitivity but may detect asymptomatic colonization. Quantitative PCR demonstrates potential for distinguishing colonization from infection, but clinical validation is required. Serum (1→3)-β-D-glucan may be elevated in PJP, although standardized cut-off values for clinical infection have not been determined. Further validation of serum markers and molecular diagnostic methods is necessary for early and accurate diagnosis in non-HIV populations.

Risk factors for Pneumocystis jiroveci pneumonia in glomerulonephritis patients receiving immunosuppressants

OBJECTIVE

Pneumocystis jiroveci pneumonia (PJP) infection is a rare but lethal complication in immunocompromised hosts. However, risk factors for PJP infection in glomerulonephritis (GN) patients receiving immunosuppressants are unknown.

METHODS

From August 2009 to July 2010, we encountered a cluster occurrence of PJP infection in our renal biopsy patients. Seven of 73 GN patients under immunosuppressant agents developed PJP infection, which were diagnosed by the Giemsa and Gomori's methenamine silver stains of the bronchoalveolar lavage specimen.

RESULTS

The average time of PJP onset was 2.4 months after immunosuppressant initiation. We found that the immunosuppressant regimens were equal between patients with and without the development of PJP infection regarding the daily dose per body weight, treatment duration, and accumulative dose per body weight. Logistic regression analysis indicated that high serum creatinine, low hemoglobin, and low absolute lymphocyte count at immunosuppressant initiation, and high chronicity indices of kidney pathology were predictors of PJP infection. In addition, patients with PJP infection had persistently worse renal function, more severe anemia, and more severe lymphocytopenia as compared to those without.

CONCLUSION

Prophylactic therapy for P. jiroveci and immunosuppressant dose reduction should be considered in GN patients with high chronicity of their kidney diseases and/or persistent lymphocytopenia.