Pneumocystis jirovecii Pneumonia in a Liver Transplant Recipient With an Adverse Reaction to Trimethoprim/Sulfamethoxazole Treated With a Sulfonamide Desensitization Protocol: Case Report

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic fungal infection that, in immunocompromised patients, can progress to respiratory failure and death. Since trimethoprim/sulfamethoxazole (TMP/SMX) chemoprophylaxis has become a standard management, the prognosis has improved. However, there are patients with a history of TMP/SMX intolerance who cannot receive chemoprophylaxis.

BACKGROUND

We report on a 53-year-old male liver recipient treated with a standard triple immunosuppressive regimen in whom TMP/SMX was waived because of a history of allergy manifested as a generalized rash with edema more than 30 years ago. At transplantation, the immunologic risk was assessed as low, and liver graft function was normal. In the third month after engraftment, he developed dyspnea at rest required constant passive oxygen therapy. Ceftriaxone, azithromycin, and clindamycin were implemented. Mycophenolate acid was stopped, and tacrolimus was reduced. High-resolution computed tomography revealed interstitial pneumonia. Pneumocystis jirovecii pneumoniae was diagnosed from bronchoalveolar lavage. Instead of TMP/SMX, pentamidine and caspofungin were also used for PJP, with no improvement. After 3 weeks, the patient deteriorated. Because of his life-threatening condition, TMP/SMX was introduced in the sulfonamide desensitization protocol, including hydrocortisone and clemastinum. Within 4 days, the patient stabilized with no signs of TMP/SMX intolerance. Pneumonia subsided within a month, and TMP/SMX was prescribed lifelong.

CONCLUSIONS

Prophylaxis for PJP with TMP/SMX still remains an important issue in transplant recipients. Adverse reaction to TMP/SMX in the past is not always a contraindication to reintroducing prophylaxis. The decision of prophylaxis avoidance should be analyzed carefully; in uncertain cases, a sulfonamide desensitization protocol should be considered.

Risk factors for Pneumocystis jirovecii pneumonia after kidney transplantation: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Pneumocystis jirovecii pneumonia (PJP), an opportunistic infection, often leads to an increase in hospitalization time and mortality rates in kidney transplant (KT) recipients. However, the risk factors associated with PJP in KT recipients remain debatable. Therefore, we conducted this meta-analysis to identify risk factors for PJP, which could potentially help to reduce PJP incidence and improve outcome of KT recipients.

METHODS

We systematically retrieved relevant studies in PubMed, EMBASE, and the Cochrane Library up to November 2023. Pooled odds ratios (ORs) or mean differences (MDs) and the corresponding 95% confidence intervals (CIs) were calculated to assess the impact of potential risk factors on the occurrence of PJP.

RESULTS

27 studies including 42383 KT recipients were included. In this meta-analysis, age at transplantation (MD = 3.48; 95% CI = .56-6.41; p = .02), cytomegalovirus (CMV) infection (OR = 4.00; 95% CI = 2.53-6.32; p = .001), BK viremia (OR = 3.38; 95% CI = 1.70-6.71; p = .001), acute rejection (OR = 3.66; 95% CI = 2.44-5.49; p = .001), ABO-incompatibility (OR = 2.51; 95% CI = 1.57-4.01; p = .001), estimated glomerular filtration rate (eGFR) (MD = -14.52; 95% CI = -25.37- (-3.67); p = .009), lymphocyte count (MD = -.54; 95% CI = -.92- (-.16); p = .006) and anti-PJP prophylaxis (OR = .53; 95% CI = .28-.98; p = .04) were significantly associated with PJP occurrence.

CONCLUSION

Our findings suggest that transplantation age greater than 50 years old, CMV infection, BK viremia, acute rejection, ABO-incompatibility, decreased eGFR and lymphopenia were risk factors for PJP.

Adjunctive glucocorticoid therapy for Pneumocystis jirovecii pneumonia in solid organ transplant recipients: A multicenter cohort, 2015-2020

Solid organ transplant recipients (SOTRs) frequently receive adjunctive glucocorticoid therapy (AGT) for Pneumocystis jirovecii pneumonia (PJP). This multicenter cohort of SOTRs with PJP admitted to 20 transplant centers in Canada, the United States, Europe, and Australia, was examined for whether AGT was associated with a lower rate of all-cause intensive care unit (ICU) admission, 90-day death, or a composite outcome (ICU admission or death). Of 172 SOTRs with PJP (median [IQR] age: 60 (51.5-67.0) years; 58 female [33.7%]), the ICU admission and death rates were 43.4%, and 20.8%, respectively. AGT was not associated with a reduced risk of ICU admission (adjusted odds ratio [aOR] [95% CI]: 0.49 [0.21-1.12]), death (aOR [95% CI]: 0.80 [0.30-2.17]), or the composite outcome (aOR [95% CI]: 0.97 [0.71-1.31]) in the propensity score-adjusted analysis. AGT was not significantly associated with at least 1 unit of the respiratory portion of the Sequential Organ Failure Assessment score improvement by day 5 (12/37 [32.4%] vs 39/111 [35.1%]; P = .78). We did not observe significant associations between AGT and ICU admission or death in SOTRs with PJP. Our findings should prompt a reevaluation of routine AGT administration in posttransplant PJP treatment and highlight the need for interventional studies.

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.

Alterations of lung microbiota in lung transplant recipients with pneumocystis jirovecii pneumonia

BACKGROUND

Increasing evidence revealed that lung microbiota dysbiosis was associated with pulmonary infection in lung transplant recipients (LTRs). Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungal pathogen that frequently causes lethal pneumonia in LTRs. However, the lung microbiota in LTRs with P. jirovecii pneumonia (PJP) remains unknow.

METHODS

In this prospective observational study, we performed metagenomic next-generation sequencing (mNGS) on 72 bronchoalveolar lavage fluid (BALF) samples from 61 LTRs (20 with PJP, 22 with PJC, 19 time-matched stable LTRs, and 11 from LTRs after PJP recovery). We compared the lung microbiota composition of LTRs with and without P. jirovecii, and analyzed the related clinical variables.

RESULTS

BALFs collected at the episode of PJP showed a more discrete distribution with a lower species diversity, and microbiota composition differed significantly compared to P. jirovecii colonization (PJC) and control group. Human gammaherpesvirus 4, Phreatobacter oligotrophus, and Pseudomonas balearica were the differential microbiota species between the PJP and the other two groups. The network analysis revealed that most species had a positive correlation, while P. jirovecii was correlated negatively with 10 species including Acinetobacter venetianus, Pseudomonas guariconensis, Paracandidimonas soli, Acinetobacter colistiniresistens, and Castellaniella defragrans, which were enriched in the control group. The microbiota composition and diversity of BALF after PJP recovery were also different from the PJP and control groups, while the main components of the PJP recovery similar to control group. Clinical variables including age, creatinine, total protein, albumin, IgG, neutrophil, lymphocyte, CD3+CD45+, CD3+CD4+ and CD3+CD8+ T cells were deeply implicated in the alterations of lung microbiota in LTRs.

CONCLUSIONS

This study suggests that LTRs with PJP had altered lung microbiota compared to PJC, control, and after recovery groups. Furthermore, lung microbiota is related to age, renal function, nutritional and immune status in LTRs.

The first case of subcutaneous mycosis caused by Muyocopron laterale in China

Muyocopron laterale is a type of endophytic fungus that parasitizes monocotyledonous plants. Cases of humans and other mammals being infected by M. laterale are very rare around the world. We report the first case of subcutaneous mycosis caused by M. laterale in China. A kidney transplant recipient was admitted for Pneumocystis carinii pneumonia and subsequently developed left calf redness and swelling due to a M. laterale infection. The patient was treated with sulfamethoxazole and voriconazole and underwent five surgical debridements and vacuum sealing drainage (VSD) applications with the left leg. The patient was eventually cured and discharged from the hospital.

The Development and Evaluation of a Prediction Model for Kidney Transplant-Based Pneumocystis carinii Pneumonia Patients Based on Hematological Indicators

BACKGROUND

This study aimed to develop a simple predictive model for early identification of the risk of adverse outcomes in kidney transplant-associated Pneumocystis carinii pneumonia (PCP) patients.

METHODS

This study encompassed 103 patients diagnosed with PCP, who received treatment at our hospital between 2018 and 2023. Among these participants, 20 were categorized as suffering from severe PCP, and, regrettably, 13 among them succumbed. Through the application of machine learning techniques and multivariate logistic regression analysis, two pivotal variables were discerned and subsequently integrated into a nomogram. The efficacy of the model was assessed via receiver operating characteristic (ROC) curves and calibration curves. Additionally, decision curve analysis (DCA) and a clinical impact curve (CIC) were employed to evaluate the clinical utility of the model. The Kaplan-Meier (KM) survival curves were utilized to ascertain the model's aptitude for risk stratification.

RESULTS

Hematological markers, namely Procalcitonin (PCT) and C-reactive protein (CRP)-to-albumin ratio (CAR), were identified through machine learning and multivariate logistic regression. These variables were subsequently utilized to formulate a predictive model, presented in the form of a nomogram. The ROC curve exhibited commendable predictive accuracy in both internal validation (AUC = 0.861) and external validation (AUC = 0.896). Within a specific threshold probability range, both DCA and CIC demonstrated notable performance. Moreover, the KM survival curve further substantiated the nomogram's efficacy in risk stratification.

CONCLUSIONS

Based on hematological parameters, especially CAR and PCT, a simple nomogram was established to stratify prognostic risk in patients with renal transplant-related PCP.

Pulmonary co-infections by Pneumocystis jirovecii and Herpesviridae: a seven-year retrospective study

BACKGROUND

Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungus responsible for Pneumocystis pneumonia (PCP) in deeply immunocompromised patients and for pulmonary colonization in individuals with mild immunosuppression or impaired respiratory function. PCP and Cytomegalovirus (CMV) co-infections have been widely described whereas those involving other Herpesviruses (HVs) such as Epstein-Barr virus (EBV), Herpes simplex virus type 1 and type 2 (HSV-1 and  -2), and Varicella zoster virus (VZV) remain scarce. To date, no data are available concerning HVs co-infections in P. jirovecii colonization.

METHODS

Our main objective was to evaluate the frequency of HVs in bronchoalveolar lavage fluid (BALF) samples from patients with PCP or with pulmonary colonization. The secondary objective was to assess the relationship between HVs and the mortality rate in PCP patients. A retrospective single-center study over a seven-year period was conducted. All patients with P. jirovecii detected using PCR in a BALF sample and for whom a PCR assay for HVs detection was performed were included in the study.

RESULTS

One hundred and twenty-five patients were included, corresponding to 77 patients with PCP and 48 colonized patients. At least one HV was detected in 54/77 (70.1%) PCP patients and in 28/48 (58.3%) colonized patients. EBV was the most frequent in both groups. Furthermore, the 30-day survival rate in PCP patients was significantly lower with [EBV + CMV] co-infection than that with EBV co-infection, [EBV + HSV-1] co-infection and without HV co-infection.

CONCLUSION

Our results show that the frequency of HV, alone or in combination is similar in PCP and colonization. They also suggest that [EBV + CMV] detection in BALF samples from PCP patients is associated with an increased mortality rate, underlying the significance to detect HVs in the course of PCP.

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 jirovecii Pneumonia after Heart Transplantation: Two Case Reports and a Review of the Literature

Post-transplant Pneumocystis jirovecii pneumonia (PcP) is an uncommon but increasingly reported disease among solid organ transplantation (SOT) recipients, associated with significant morbidity and mortality. Although the introduction of PcP prophylaxis has reduced its overall incidence, its prevalence continues to be high, especially during the second year after transplant, the period following prophylaxis discontinuation. We recently described two cases of PcP occurring more than one year after heart transplantation (HT) in patients who were no longer receiving PcP prophylaxis according to the local protocol. In both cases, the disease was diagnosed following the diagnosis of a viral illness, resulting in a significantly increased risk for PcP. While current heart transplantation guidelines recommend Pneumocystis jirovecii prophylaxis for up to 6-12 months after transplantation, after that period they only suggest an extended prophylaxis regimen in high-risk patients. Recent studies have identified several new risk factors that may be linked to an increased risk of PcP infection, including medication regimens and patient characteristics. Similarly, the indication for PcP prophylaxis in non-HIV patients has been expanded in relation to the introduction of new medications and therapeutic regimens for immune-mediated diseases. In our experience, the first patient was successfully treated with non-invasive ventilation, while the second required tracheal intubation, invasive ventilation, and extracorporeal CO2 removal due to severe respiratory failure. The aim of this double case report is to review the current timing of PcP prophylaxis after HT, the specific potential risk factors for PcP after HT, and the determinants of a prompt diagnosis and therapeutic approach in critically ill patients. We will also present a possible proposal for future investigations on indications for long-term prophylaxis.

Risk factors and outcomes of Pneumocystis pneumonia in solid organ transplant recipients: Impact of posttransplant lymphoproliferative disorder

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a potentially fatal infection afflicting the immunocompromised population, including solid organ transplant (SOT) recipients. Several risk factors have been described; however, little is known regarding the risk of PJP in SOT recipients with posttransplant lymphoproliferative disorder (PTLD).

METHODS

We performed a nested case-control study of SOT recipients diagnosed with PJP from 2000 to 2020. PJP was defined as positive microscopy or polymerase chain reaction testing with compatible symptoms and radiographic findings. Control patients were matched 2:1 by year of first transplant, first transplanted organ, transplant center, and sex. Multivariable conditional logistic regression was performed to test associations with PJP and Cox regression analyzed post-PJP outcomes.

RESULTS

Sixty-seven PJP cases were matched to 134 controls. The most common transplant was kidney (55.2%). Fourteen patients had a history of PTLD, 12 of whom developed PJP. After adjusting for age, acute rejection, cytomegalovirus infection, PJP prophylaxis, and lymphopenia (lymphocyte count < .5 × 109 /L), PTLD was independently associated with PJP (OR 14.0, 95% CI 1.7-114.5; p = .014). Lymphopenia was also a significant association (OR 8.2, 95% CI 3.2-20.7; p < .001). PJP was associated with mortality within 90 days of diagnosis (p < .001), but not after 90 days (p = .317). PJP was also associated with 90-day death-censored renal allograft loss (p = .026).

CONCLUSIONS

PTLD is independently associated with PJP after adjustment for recognized risk factors. This is likely influenced by PTLD-directed chemotherapy, particularly rituximab-containing regimens. PJP is associated with early mortality, but this effect is not persistent after 90 days. PJP prophylaxis should be considered in SOT recipients with PTLD.

Machine Learning Models for Prediction of Severe Pneumocystis carinii Pneumonia after Kidney Transplantation: A Single-Center Retrospective Study

BACKGROUND

The objective of this study was to formulate and validate a prognostic model for postoperative severe Pneumocystis carinii pneumonia (SPCP) in kidney transplant recipients utilizing machine learning algorithms, and to compare the performance of various models.

METHODS

Clinical manifestations and laboratory test results upon admission were gathered as variables for 88 patients who experienced PCP following kidney transplantation. The most discriminative variables were identified, and subsequently, Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), K-Nearest Neighbor (KNN), Light Gradient Boosting Machine (LGBM), and eXtreme Gradient Boosting (XGB) models were constructed. Finally, the models' predictive capabilities were assessed through ROC curves, sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and F1-scores. The Shapley additive explanations (SHAP) algorithm was employed to elucidate the contributions of the most effective model's variables.

RESULTS

Through lasso regression, five features-hemoglobin (Hb), Procalcitonin (PCT), C-reactive protein (CRP), progressive dyspnea, and Albumin (ALB)-were identified, and six machine learning models were developed using these variables after evaluating their correlation and multicollinearity. In the validation cohort, the RF model demonstrated the highest AUC (0.920 (0.810-1.000), F1-Score (0.8), accuracy (0.885), sensitivity (0.818), PPV (0.667), and NPV (0.913) among the six models, while the XGB and KNN models exhibited the highest specificity (0.909) among the six models. Notably, CRP exerted a significant influence on the models, as revealed by SHAP and feature importance rankings.

CONCLUSIONS

Machine learning algorithms offer a viable approach for constructing prognostic models to predict the development of severe disease following PCP in kidney transplant recipients, with potential practical applications.

Trends in the Epidemiology of Pneumocystis Pneumonia in Immunocompromised Patients without HIV Infection

The increasing morbidity and mortality of life-threatening Pneumocystis pneumonia (PCP) in immunocompromised people poses a global concern, prompting the World Health Organization to list it as one of the 19 priority invasive fungal diseases, calling for increased research and public health action. In response to this initiative, we provide this review on the epidemiology of PCP in non-HIV patients with various immunodeficient conditions, including the use of immunosuppressive agents, cancer therapies, solid organ and stem cell transplantation, autoimmune and inflammatory diseases, inherited or primary immunodeficiencies, and COVID-19. Special attention is given to the molecular epidemiology of PCP outbreaks in solid organ transplant recipients; the risk of PCP associated with the increasing use of immunodepleting monoclonal antibodies and a wide range of genetic defects causing primary immunodeficiency; the trend of concurrent infection of PCP in COVID-19; the prevalence of colonization; and the rising evidence supporting de novo infection rather than reactivation of latent infection in the pathogenesis of PCP. Additionally, we provide a concise discussion of the varying effects of different immunodeficient conditions on distinct components of the immune system. The objective of this review is to increase awareness and knowledge of PCP in non-HIV patients, thereby improving the early identification and treatment of patients susceptible to PCP.

Current Concepts in the Diagnosis and Management of Pneumocystis Pneumonia in Solid Organ Transplantation

Pneumocystis infection manifests predominantly as an interstitial pneumonia in immunocompromised patients. Diagnostic testing in the appropriate clinical context can be highly sensitive and specific and involves radiographic imaging, fungal biomarkers, nucleic acid amplification, histopathology, and lung fluid or tissue sampling. Trimethoprim-sulfamethoxazole remains the first-choice agent for treatment and prophylaxis. Investigation continues to promote a deeper understanding of the pathogen's ecology, epidemiology, host susceptibility, and optimal treatment and prevention strategies in solid organ transplant recipients.

Risk factors for Pneumocystis pneumonia with acute respiratory failure among kidney transplant recipients

PURPOSE

One of the rare life-threatening fungal infections is pneumocystis pneumonia (PCP). Immunocompromised patients are the main vulnerable population. We investigate the risk factors associated with the development of severe PCP infection with acute respiratory failure after kidney transplantation.

MATERIALS AND METHODS

This is a retrospective, single-center, case-control study. PCP patients who are kidney transplant recipients and required high-flow oxygen support or mechanical ventilation between March 2009 and February 2017 were included in the study. The comparison was conducted between the non-severe and severe PCP groups. To identify associated risk factors, we performed univariate and multivariate logistic regression.

RESULTS

Among the total 2,330 kidney transplant recipients, 50 patients (2.1%) were diagnosed with PCP. Of these, 27 patients (54.0%) had severe PCP and 7 patients (14.0%) died, all of them were severe PCP patients. In the severe PCP group, the time from transplantation to PCP diagnosis (23.4 ± 24.9 months vs. 13.7 ± 9.9 months, p = 0.090) was insignificantly faster than in the non-severe PCP group. According to multiple logistic regression analysis, the significant risk factors associated with severe PCP were as follows, age (odds ratios (OR) 1.07; 95% confidence intervals (CI): 1.01-1.13; p = 0.027), time from transplantation to PCP diagnosis (odds ratios (OR) 0.92; 95% confidence intervals (CI): 0.86-0.99; p = 0.024), lymphopenia (OR 6.48; 95% CI: 1.05-40.09; p = 0.044), and history of acute rejection within 1 year (OR 8.28; 95% CI: 1.29-53.20; p = 0.026).

CONCLUSION

Patients who have lymphopenia at the time of hospital admission or have been recently treated with acute rejection are more likely to progress to severe PCP, requiring intensive monitoring and aggressive treatment.

Single-center retrospective analysis of Pneumocystis jirovecii pneumonia in patients after deceased donor renal transplantation

OBJECTIVE

To investigate the clinical features, early diagnosis, and treatment methods of Pneumocystis jirovecii pneumonia (PJP) after renal transplantation (RT).

METHODS

We retrospectively analyzed the clinical data of 80 patients with confirmed PJP who underwent RT between 2018 and 2021 in our hospital.

RESULTS

In the present study, the incidence of PJP was 6.2% (80/1300). A 50% of cases (40 out of 80 patients) had developed a PJP infection during the first 6 months after RT and 81.3% (65 out of 80 patients) within 12 months. The median onset time of PJP was 6.5 months after RT. The most common symptom was fever (73.8%), followed by progressive dyspnea (51.3%) and dry cough (31.3%). In the initial phase of PJP, the most frequent CT finding was the presence of diffuse ground-grass shadows. In all, 27.5%, 37.5%, and 35% patients were diagnosed by induced sputum metagenomic next-generation sequencing (mNGS), peripheral blood mNGS, and characteristic clinical diagnostic features, respectively. The median 1,3-β-D-glucan level was 500 pg/mL, while the median C-reactive protein level was 63.4 mg/L. In most patients (83.8%), the procalcitonin levels were negative. The mean serum creatinine level was 171.9 ± 87.4 μmol/L. Of the 80 patients, 37 (46.2%) had coexisting cytomegalovirus (CMV) infection. All patients were treated with trimethoprim-sulfamethoxazole and third generation cephalosporin to prevent bacterial infection. The methylprednisolone dose (40-120 mg/d) varied according to illness.

CONCLUSION

PJP usually occurs within 1 year after RT, typically within 6 months. Fever, dry cough, and progressive dyspnea are the most common clinical symptoms. PJP should be highly suspected if the patient has clinical symptoms and diffuse, patchy, ground-glass opacities on CT in both lungs after RT within 1 year. Peripheral blood or induced sputum mNGS is helpful for early diagnosis of PJP. Trimethoprim-sulfamethoxazole is still the first choice for the treatment of PJP. Combined use of caspofungin can reduce the dose and adverse reactions of trimethoprim-sulfamethoxazole in theory.

Cytomegalovirus Exposure and the Risk of Overall Infection After Kidney Transplantation: A Cohort Study on the Indirect Effects Attributable to Viral Replication

Previous reports hypothesized that cytomegalovirus (CMV) may predispose to non-CMV infection after kidney transplantation (KT). We analysed the incidence of non-CMV infection (overall, bacterial and opportunistic) in 291 KT recipients according to the previous development of any level or high-level (≥1,000 IU/ml) CMV viremia. Exposure to CMV replication was assessed throughout fixed intervals covering first the 30, 90, 180 and 360 post-transplant days (cumulative exposure) and non-overlapping preceding periods (recent exposure). Adjusted Cox models were constructed for each landmark analysis. Overall, 67.7 and 50.5% patients experienced non-CMV and CMV infection, respectively. Patients with cumulative CMV exposure had higher incidence of non-CMV infection beyond days 30 (p-value = 0.002) and 90 (p-value = 0.068), although these associations did not remain after multivariable adjustment. No significant associations were observed for the remaining landmark models (including those based on high-level viremia or recent CMV exposure), or when bacterial and opportunistic infection were separately analysed. There were no differences in viral kinetics (peak CMV viremia and area under curve of CMV viral load) either. Our findings do not support the existence of an independent association between previous CMV exposure and the overall risk of post-transplant infection, although results might be affected by power limitations.

Risk factors of invasive fungal infections in lung transplant recipients: A systematic review and meta-analysis

BACKGROUND

Invasive fungal infection (IFI) remains a common complication after lung transplantation, causing significant morbidity and mortality. We have attempted to quantify systematically risk factors of IFI in lung transplant recipients.

METHODS

Studies were retrieved from Ovid MEDLINE, Ovid Embase, Cochrane database of systematic reviews and Cochrane central register of controlled trials. All case-control and cohort studies evaluating the risk factors of IFI in adult lung transplant recipients were screened. Two researchers reviewed and assessed all studies independently. We pooled the estimated effect of each factor associated with IFI by using a random effect model.

RESULTS

Eight studies were included in the systematic review and 5 studies were eligible for the meta-analysis. Rates of IFI range from 8% to 33% in lung transplant recipients. Independent risk factors for invasive aspergillosis (IA) in lung transplantation include previous fungal colonization (odds ratio [OR] 2.44; 95% confidence interval [CI] 0.08-0.47), cytomegalovirus infection (OR 1.96; 95% CI 1.08-3.56), and single lung transplantation (OR 1.77; 95% CI 1.08-2.91). Pre-emptive antifungal therapy is a protective factor for IA in lung transplant (OR 0.2; 95% CI 0.08-0.47).

CONCLUSION

Cytomegalovirus infection, previous fungal colonization and single lung transplantation independently increase the risk of IA in lung transplant recipients. Pre-emptive antifungal therapy is a protective factor for IA in the lung transplant population.

Differences Between Infectious Disease Events in First Liver Transplant Versus Retransplantation in the Swiss Transplant Cohort Study

Retransplantation after graft failure is increasingly performed, and inferior graft survival, patient survival, and quality of life has been reported. The role of infectious disease (ID) events in this less favorable outcome is unknown. We analyzed ID events after first liver transplantation (FLTpx) and retransplantation (reLTpx) in the Swiss Transplant Cohort Study. Clinical factors were compared after FLTpx and reLTpx, and survival analysis was applied to compare the time to ID events after FLTpx and after reLTpx, adjusted for age, sex, Model for End-Stage Liver Disease score, donor type, liver transplant type (whole versus split liver), and duration of transplant surgery. In total, 60 patients were included (65.0% male, median age of 56 years). Overall, 343 ID events were observed: 204 (59.5%) after the FLTpx and 139 (40.5%) after reLTpx. Bacterial infections were most frequent (193/343, 56.3%), followed by viral (43/343, 12.5%) and fungal (28/343, 8.2%) infections, with less infections by Candida spp. but more by Aspergillus spp. after reLTpx (P = 0.01). The most frequent infection site was bloodstream infection (86, 21.3%), followed by liver and biliary tract (83, 20.5%) and intraabdominal (63, 15.6%) infections. After reLTpx, more respiratory tract and surgical site infections were observed (P < 0.001). The time to first infection was shorter after FLTpx (adjusted hazard ratio [HR], 0.5; 95%-confidence interval [CI], 0.3-1.0; P = 0.04). Reduced hazards for ID events after reLTpx were also observed when modelling recurrent events (adjusted HR, 0.5; CI, 0.3-0.8; P = 0.003). The number of infections was comparable after FLTpx and reLTpx; however, differences regarding infection sites and fungal species were observed. Hazards were reduced for infection after reLTpx.

Latent Cytomegalovirus Reactivation in Patients With Liver Failure: A 10-Year Retrospective Case-Control Study, 2011-2020

Background

The aim of this study was to explore potential risk factors for cytomegalovirus (CMV) reactivation and their impact on liver failure patient outcomes.

Methods

A 10-year retrospective case-control study was conducted in adult participants, who were diagnosed with liver failure and had undergone CMV DNA tests. CMV reactivation cases were matched with controls at a 2:1 ratio based on age, sex, and year of admission. Univariate and multivariate analyses were used to explore risk factors for CMV reactivation.

Results

Between January 2011 and April 2020, 198 adult patients with liver failure and available CMV DNA test results were enrolled into the study. Among them, 33 patients had detectable CMV DNA in their plasma (16.7%). Clinical manifestations and liver function were comparable between the CMV reactivation and non-reactivation groups. However, CMV reactivation may triple mortality in patients with liver failure. We found that nearly 50% of patients in the CMV-positive group received glucocorticoids, compared to 13.6% in the CMV-negative group (P=0.000). The median total glucocorticoid dose included 836.5 mg of methylprednisolone (IQR 308.7-1259.0 mg) in the CMV-positive group, which was significantly higher than that in the CMV-negative group. A multivariate analysis revealed that glucocorticoid use significantly increased the risk of CMV reactivation (adjusted OR, 4.84; 95% CI, 1.61-14.49; P=0.005). Patients with CMV reactivation tended to be associated with higher white cell counts (adjusted OR, 1.21; 95% CI, 1.08-1.36; P=0.002).

Conclusions

High intravenous glucocorticoid doses may be the most important risk factor for CMV reactivation in liver failure.

The Changing Landscape of Pneumocystis Jiroveci Infection in Kidney Transplant Recipients: Single-Center Experience of Late-Onset Pneumocystis Pneumonia

BACKGROUND

Pneumocystis jiroveci pneumonia (PCP) is a life-threatening pulmonary infection after kidney transplantation (KTx). Its onset in the current era of modern immunosuppression and of routine use of universal PCP prophylaxis seems to differ from its onset in previous decades in terms of late onset with subtle clinical presentation, indicating a need for increased vigilance.

METHODS

We retrospectively studied all KTx recipients from our center who underwent bronchoscopy and bronchoalveolar lavage (BAL) between 2009 and 2018. Of these, all cases with confirmed PCP any time after the first post-KTx year were included in the analysis.

RESULTS

Among 60 patients with KTx who had undergone bronchoscopy and BAL, 12 cases with late-onset PCP were identified. PCP appeared late at a median of 10.8 (interquartile range, 2.4-15.8) years after transplantation. Patients' mean age was 59 years, and all were receiving stable low-dose immunosuppression. Most of the patients (67%) had received PCP prophylaxis after KTx. Five out of 12 patients (42%) had concomitant cytomegalovirus (CMV) reactivation at the time of PCP. In almost all cases, clinical presentation was mild. Treatment consisted of trimethoprim-sulfamethoxazole (TMP-SMX) and intravenous corticosteroid administration, and concomitant immunosuppression was temporarily reduced or withdrawn. Outcome was generally good. None of the patients developed respiratory insufficiency or required mechanical ventilation. One patient died as a result of sepsis, and 3 more with preexisting advanced chronic kidney disease subsequently lost their grafts.

CONCLUSION

Renal transplant recipients are at risk of late-onset PCP, even at a steady state of low-dose maintenance immunosuppression. Because of its subtle clinical presentation, high suspicion of the disease is warranted. Its early recognition and proper management are essential for a successful outcome.

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

BACKGROUND

Solid organ transplant (SOT) recipients are at risk of Pneumocystis pneumonia (PCP). PCP is associated with significant morbidity and mortality. The effect of acute T cell-mediated rejection (TCMR) on post-transplant PCP has not been determined yet.

METHODS

In this case-control study, we estimated the risk of PCP following acute TCMR during a lookback period of 180 days. We also determined the effects of contributing factors such as CMV infection.

RESULTS

We compared 15 SOT (8 kidney, 4 heart, 2 liver, and 1 kidney-pancreas) recipients with PCP with 60 matched recipients who did not develop PCP (control group) during the study period (December 2013 to February 2016). PCP occurred after a complete course of prophylaxis (ie, late-onset PCP) in 60% of patients. Patients with PCP frequently required intensive care unit (ICU) admission (73.3%). Post-transplant PCP was associated with considerable allograft loss (53.4%) and mortality (26.7%). In the 6-month lookback period, acute TCMR (OR: 13.1, 95% CI: 3.2, 53.2), and CMV infection (OR: 15.1,95% CI: 4.0, 53.2.1) were significantly associated with post-transplant PCP.

CONCLUSIONS

Post-transplant PCP is associated with substantial risk of ICU admission, allograft failure, and mortality. Anti-Pneumocystis prophylaxis for at least 6 months following acute TCMR may reduce the risk.

Burden and Timeline of Infectious Diseases in the First Year After Solid Organ Transplantation in the Swiss Transplant Cohort Study

Background

The burden and timeline of posttransplant infections are not comprehensively documented in the current era of immunosuppression and prophylaxis.

Methods

In this prospective study nested within the Swiss Transplant Cohort Study (STCS), all clinically relevant infections were identified by transplant–infectious diseases physicians in persons receiving solid organ transplant (SOT) between May 2008 and December 2014 with ≥12 months of follow-up.

Results

Among 3541 SOT recipients, 2761 (1612 kidney, 577 liver, 286 lung, 213 heart, and 73 kidney-pancreas) had ≥12 months of follow-up; 1520 patients (55%) suffered 3520 infections during the first year posttransplantation. Burden and timelines of clinically relevant infections differed between transplantations. Bacteria were responsible for 2202 infections (63%) prevailing throughout the year, with a predominance of Enterobacteriaceae (54%) as urinary pathogens in heart, lung, and kidney transplant recipients, and as digestive tract pathogens in liver transplant recipients. Enterococcus spp (20%) occurred as urinary tract pathogens in kidney transplant recipients and as digestive tract pathogens in liver transplant recipients, and Pseudomonas aeruginosa (9%) in lung transplant recipients. Among 1039 viral infections, herpesviruses predominated (51%) in kidney, liver, and heart transplant recipients. Among 263 fungal infections, Candida spp (60%) prevailed as digestive tract pathogens in liver transplant recipients. Opportunistic pathogens, including Aspergillus fumigatus (1.4%) and cytomegalovirus (6%), were rare, scattering over 12 months across all SOT recipients.

Conclusions

In the current era of immunosuppression and prophylaxis, SOT recipients experience a high burden of infections throughout the first year posttransplantation, with rare opportunistic pathogens and a predominance of bacteria.

Clinical descriptive analysis of severe Pneumocystis jirovecii pneumonia in renal transplantation recipients

Pneumocystis jirovecii (P. jirovecii) pneumonia (PJP) is an opportunistic fungal infection after renal transplantation, which is always severe, difficult to diagnose, combined with multiple complications and have poor prognosis. We retrospectively analyzed clinical data, including risk factors, diagnosis, treatment and complications of seven clinical cases suffered with severe PJP after renal transplantation in our department in 2019. All the seven recipients were routinely prescribed with PJP prophylaxis after renal transplantation, and six of them suffered acute graft rejection before the infection. P. jirovecii sequence was identified in blood or broncho-alveolar lavage fluid (BALF) by the metagenomic next-generation sequencing (mNGS) in all patients. All the patients were improved with the therapy trimethoprim-sulfamethoxazole (TMP-SMX) combined with caspofungin for the PJP treatment, but suffered with complications including renal insufficiency, leukopenia, thrombocytopenia, gastrointestinal bleeding, mediastinalemphysema, pulmonary hemorrhage, and hemophagocytic syndrome and other severe infections. Taken together, mNGS is a powerful tool that could be used to diagnose PJP in renal transplantation recipients. And PJP prophylaxis should be prescribed during and after treatment for acute rejection. TMP-SMX is the first-line and effective drug for PJP treatment, but the complications are always life-threatening and lead to poor prognosis. We should pay attention to these life-threatening complications.

Pneumocystis jirovecii: a review with a focus on prevention and treatment

Introduction: Pneumocystis jirovecii (PJ) is an opportunistic fungal pathogen that can cause severe pneumonia in immunocompromised hosts. Risk factors for Pneumocystis jirovecii pneumonia (PJP) include HIV, organ transplant, malignancy, certain inflammatory or rheumatologic conditions, and associated therapies and conditions that result in cell-mediated immune deficiency. Clinical signs of PJP are nonspecific and definitive diagnosis requires direct detection of the organism in lower respiratory secretions or tissue. First-line therapy for prophylaxis and treatment remains trimethoprim-sulfamethoxazole (TMP-SMX), though intolerance or allergy, and rarely treatment failure, may necessitate alternate therapeutics, such as dapsone, pentamidine, atovaquone, clindamycin, primaquine and most recently, echinocandins as adjunctive therapy. In people living with HIV (PLWH), adjunctive corticosteroid use in treatment has shown a mortality benefit.Areas covered: This review article covers the epidemiology, pathophysiology, diagnosis, microbiology, prophylaxis indications, prophylactic therapies, and treatments.Expert opinion: TMP-SMX has been first-line therapy for treating and preventing pneumocystis for decades. However, its adverse effects are not uncommon, particularly during treatment. Second-line therapies may be better tolerated, but often sacrifice efficacy. Echinocandins show some promise for new combination therapies; however, further studies are needed to define optimal antimicrobial therapy for PJP as well as the role of corticosteroids in those without HIV.

No association of genetic variants in TLR4, TNF-α, IL10, IFN-γ, and IL37 in cytomegalovirus-positive renal allograft recipients with active CMV infection-Subanalysis of the prospective randomised VIPP study

Background

Cytomegalovirus (CMV) infection is amongst the most important factors complicating solid organ transplantation. In a large prospective randomized clinical trial, valganciclovir prophylaxis reduced the occurrence of CMV infection and disease compared with preemptive therapy in CMV-positive renal allograft recipients (VIPP study; NCT00372229). Here, we present a subanalysis of the VIPP study, investigating single nucleotide polymorphisms (SNPs) in immune-response-related genes and their association with active CMV infection, CMV disease, graft loss or death, rejection, infections, and leukopenia.

Methods

Based on literature research ten SNPs were analyzed for TLR4, three for IFN-γ, six for IL10, nine for IL37, and two for TNF-α. An asymptotic independence test (Cochran-Armitage trend test) was used to examine associations between SNPs and the occurrence of CMV infection or other negative outcomes. Statistical significance was defined as p<0.05 and Bonferroni correction for multiple testing was performed.

Results

SNPs were analyzed on 116 blood samples. No associations were found between the analyzed SNPs and the occurrence of CMV infection, rejection and leukopenia in all patients. For IL37 rs2723186, an association with CMV disease (p = 0.0499), for IL10 rs1800872, with graft loss or death (p = 0.0207) and for IL10 rs3024496, with infections (p = 0.0258) was observed in all patients, however did not hold true after correction for multiple testing.

Conclusion

The study did not reveal significant associations between the analyzed SNPs and the occurrence of negative outcomes in CMV-positive renal transplant recipients after correction for multiple testing. The results of this association analysis may be of use in guiding future research efforts.

The risk factor analysis and treatment experience in pneumocystis jirovecii pneumonia after kidney transplantation

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection among solid organ transplantation. The occurrence of PJP is dangerous and fatal if there is no early identification and sufficient treatment.

OBJECTIVE

The aim of this study was to evaluate the risk factors and provide appropriate strategies of prophylaxis and treatment for PJP after kidney transplantation in our centre.

PATIENTS/METHODS

From January 2009 to December 2018, a total of 167 kidney transplantation recipients with pneumonia were enrolled, including 47 PJP patients as PJP group and 120 non-PJP patients as control group. The clinical characteristics of the two groups were analysed retrospectively.

RESULTS

Multivariate analysis showed that high total dosage of ATG [OR, 2.03; 95% CI, 1.12-3.68] and cytomegalovirus (CMV) infection were independent risk factors for PJP. Trimethoprim-sulfamethoxazole (TMP-SMX) (1.44 g q6h)-based treatment was used for 2 weeks, and its dosage and course were adjusted according to the therapeutic effect and side effects. Forty-five cases were recovered after 3 months of follow-up, and two patients died of respiratory failure. TMP-SMX (0.48 g/day) prophylaxis was used for 3-6 months and prolonged to 7-8 months after treatment for acute rejection, which reduced the incidence of PJP compared with those without prophylaxis.

CONCLUSION

Our study suggests that the high total dosage of ATG and CMV infection indicate the increased risk of PJP. The strategies of prophylaxis and treatment for PJP after kidney transplantation in our centre were effective.

A Comprehensive Evaluation of Risk Factors for Pneumocystis Jirovecii Pneumonia in Adult Solid Organ Transplant Recipients: a Systematic Review and Meta-Analysis

BACKGROUND

There is no consensus guidance on when to reinitiate Pneumocystis jirovecii pneumonia (PJP) prophylaxis in solid organ transplant (SOT) recipients at increased risk. The 2019 American Society of Transplantation Infectious Diseases Community of Practice (AST IDCOP) guidelines suggested to continue or reinstitute PJP prophylaxis in those receiving intensified immunosuppression for graft rejection, CMV infection, higher dose of corticosteroids, or prolonged neutropenia.

METHODS

A literature search was conducted evaluating all literature from existence through April 22, 2020 using MEDLINE and EMBASE. (PROSPERO: CRD42019134204) RESULTS:: A total of 30 studies with 413 276 SOT recipients were included. The following factors were associated with PJP development: acute rejection (pooled odds ratio (pOR) = 2.35 (1.69, 3.26), study heterogeneity index (I)= 23.4%), cytomegalovirus (CMV)-related illnesses (pOR = 3.14 (2.30, 4.29), I=48%), absolute lymphocyte count < 500 cells/mm (pOR = 6.29[3.56, 11.13], I 0%), BK-related diseases (pOR = 2.59[1.22, 5.49], I 0%), HLA mismatch ≥ 3 (pOR = 1.83 [1.06, 3.17], I= 0%), rituximab use (pOR =3.03 (1.82, 5.04); I =0%) and polyclonal antibodies use for rejection (pOR = 3.92 [1.87, 8.19], I= 0%). On the other hand, sex, CMV mismatch, interleukin-2 inhibitors, corticosteroids for rejection, and plasmapheresis were not associated with developing PJP.

CONCLUSION

PJP prophylaxis should be considered in SOT recipients with lymphopenia, BK-related infections and rituximab exposure in addition to the previously mentioned risk factors in the AST IDCOP guidelines.

Experience with a six-month regimen of Pneumocystis pneumonia prophylaxis in 122 HIV-positive kidney transplant recipients

Anti-Pneumocystis pneumonia (PCP) prophylaxis is recommended for 3 to 6 months post-transplant in HIV-negative kidney transplant recipients. For HIV-positive kidney transplant recipients, there is no definite duration of primary prophylaxis and is often prescribed life-long. The objective of this study was to determine the incidence of PCP in HIV-positive recipients who received 6 months of prophylaxis with trimethoprim-sulfamethoxazole or an alternative agent. One hundred and twenty-two HIV-positive recipients received a kidney transplant from 2001 to 2017 at Hahnemann University Hospital. Most patients received induction immunosuppression with an IL-2 receptor antagonist, with or without intravenous immunoglobulin. Only one patient received anti-thymocyte globulin. Maintenance immunosuppression included a calcineurin-inhibitor (tacrolimus or cyclosporine), an antiproliferative agent (mycophenolate or sirolimus), and prednisone. Mean CD4 cell count was 461 ± 127 cells/uL prior to transplant and 463 ± 229 cells/μL at 6 to 12 months after transplant. None of the recipients developed PCP after a median follow-up of 2.88 years (IQR 1.16-4.87). Based on our observation, a 6-month regimen of PCP prophylaxis may be sufficient among HIV-positive recipients, similar to those without HIV infection.

Long-lasting cluster of nosocomial pneumonia with a single Pneumocystis jirovecii genotype involving different organ allograft recipients

Pneumocystis pneumonia (PCP) outbreaks may occur in solid organ transplant (SOT) patients. Transmissibility of Pneumocystis jirovecii among SOT and non-SOT patients has not been investigated. Ten SOT (ie, 4 heart, 4 kidney, 2 liver allograft recipients) and 11 non-SOT (ie, 7 HIV-infected, 3 hematologic malignancies, and 1 stem cell transplant) patients with PCP were admitted to London Health Sciences Center (LHSC) from October 2014 to August 2016. We investigated the course of illness and outcome of PCP in SOT and non-SOT patients. Post-transplant PCP was frequently an acute-onset disease (90% vs. 18.2%, p = .01) requiring ICU admission (70% vs. 20%, p = .03) and hemodialysis (60% vs. 0, p = .003). Mortality was more frequent in SOT patients (40% vs. 18.1%, p = .36). Multilocus sequence typing (MLST) demonstrated circulation of a single genotype of P. jirovecii among SOT patients. However, 8 different genotypes were detected from non-SOT patients. Reinstitution of prophylaxis successfully controlled post-transplant cluster until end of observation period in October 2019. No transmission was detected from non-SOT patients to SOT recipients. Detection of a single P. jirovecii genotype from all SOT recipients highlights the likelihood of nosocomial transmission. No source control method is recommended by current guidelines. Improvement of preventive strategies is required.

Identification of Predictive Markers and Outcomes of Late-onset Pneumocystis jirovecii Pneumonia in Kidney Transplant Recipients

Background

In the era of prophylaxis, Pneumocystis pneumonia (PCP) has become a late-onset opportunistic infection requiring indications for prolonged prophylaxis to be defined. The primary objective of our study was therefore to evaluate risk factors associated with late-onset PCP. The secondary objective was to assess the impact of this infection on graft and patient survival.

Methods

We conducted a French case-control study in Bordeaux and Toulouse center by matching 1 case to 1–2 controls from the same center based on the transplant date and the type of induction treatment.

Results

Seventy cases and 134 controls were included. PCP occurred at a median of 3 years after transplantation. The total lymphocyte count and CD4+ and CD8+ T-lymphocyte values were lower in the cases than in their matched controls on the day of infection and annually up to 4 years earlier. The covariables independently associated with PCP were the total lymphocyte count 1 year before Pneumocystis, mTOR inhibitors used as maintenance immunosuppressive drugs, and the administration of corticosteroid boluses used in acute rejection. A total lymphocyte count threshold &lt;1000/µL offered the best predictive value for infection occurrence. PCP was associated with high incidence of graft loss and patient death (30% and 17% respectively, 3 years after PCP).

Conclusions

Pneumocystis pneumonia has dramatic consequences in kidney transplant recipients; a targeted prophylaxis based on simple criteria, such as chronic lymphopenia and/or history of corticosteroid boluses, could be useful to avoid life-threatening complications.

Hypercalcemia as an Early Finding of Opportunistic Fungal Pneumonia in Renal Transplantation: A Case Series Report

BACKGROUND

Pneumonia caused by opportunistic fungi is a serious complication in immunocompromised patients. Hypercalcemia has been described in renal transplantation associated with Pneumocystis jirovecii (PJP) or Histoplasma capsulatum (HCP) pneumonia.

METHODS

We describe 5 patients who underwent kidney transplant between 2014 and 2019 and developed hypercalcemia before the diagnosis of pulmonary fungal infection: 4 patients with PJP and 1 with HCP. We assessed calcium metabolism and kidney function by total and ionized calcium, phosphorus, intact parathormone (iPTH), 25-OH vitamin D, 1,25(OH)2 vitamin D, and serum creatinine levels.

RESULTS

Mean albumin-corrected calcium and ionized calcium were 12.56 mg/dL (range, 10.8-13.8 mg/dL) and 1.57 mmol/L (range, 1.43-1.69 mmol/L). Patients were normocalcemic, at 10.12 mg/dL (range, 9.6-10.5 mg/dL), before diagnosis and resolved hypercalcemia after antifungal treatment, at 8.86 mg/dL (range, 8.0-9.5 mg/dL). All patients had low or normal iPTH values, at 29.1 pg/mL (range, <3-44 pg/mL), with higher PTH levels 3 months before diagnosis and after treatment, at 147.3 pg/mL (range, 28.1-479 pg/mL) and 117.5 pg/mL (range, 18.2-245 pg/mL), respectively. The mean value for 25-OH vitamin D was 30.8 ng/mL (range, 14.6-62.8 ng/mL). This supports a PTH-independent mechanism, and we postulated an extrarenal production of 1,25(OH)2 vitamin D.

CONCLUSION

In kidney transplant patients, hypercalcemia independent of PTH and refractory to treatment should alert for the possibility of opportunistic fungal pneumonia.

Prevention and therapy of viral infections in patients with solid organ transplantation

Solid organ transplantation (SOT) is the best treatment option for end-stage organ disease. The number of SOT procedures has been steadily increasing worldwide during the past decades. This trend has been accompanied by the continuous incorporation of new antimicrobial drugs and by the refinement of strategies aimed at minimizing the risk of opportunistic infection. Nonetheless, viral infections, which can occur at any stage of the post-transplant period, remain a clinical challenge that negatively impacts both patient and graft outcomes. This review offers an overview of the most relevant viral infections in the SOT population, with a focus on herpesviruses (cytomegalovirus, Epstein-Barr virus, varicella-zoster virus, and herpes simplex virus 1 and 2) and polyomaviruses (human BK polyomavirus). In addition, the currently recommended prophylactic and treatment approaches are summarized, as well as the new antiviral agents in different phases of clinical development.

The impact of cytomegalovirus infection on clinical severity and outcomes in kidney transplant recipients with Pneumocystis jirovecii pneumonia

Cytomegalovirus (CMV) infection is associated with Pneumocystis jirovecii pneumonia (PJP) in kidney transplant recipients (KTRs), but its impact on clinical severity and outcomes in KTRs with PJP is unknown. We reviewed 1994 medical records of KTRs from January 1997 to March 2019. PJP or CMV infection was diagnosed by polymerase chain reaction or culturing using blood or respiratory specimens. We divided patients into PJP and PJP+CMV groups, and evaluated the clinical severity and outcomes. Fifty two patients had PJP (2.6%) in the whole study cohort. Among patients with PJP, 38 (73.1%) had PJP alone and 14 (26.9%) had combined PJP and CMV co-infection. The PJP+CMV group showed worse laboratory findings (serum albumin and C-reactive protein, P = 0.010 for both) and higher requirement of continuous renal replacement therapy than the PJP group (P = 0.050). The pneumonia severity was worse in the PJP+CMV group than in the PJP group (P < 0.05), and CMV infection was a high risk factor of pneumonia severity (odds ratio 16.0; P = 0.002). The graft function was worse in the PJP+CMV group (P < 0.001), and the incidence of graft failure was higher in the PJP+CMV group than in the PJP group (85.7% vs 36.8%; P < 0.001). Mortality was double in the PJP+CMV group than in the PJP group, but not statistically significant (21.4% vs 10.5%; P = 0.370). Our results show that approximately one in four patients with PJP after kidney transplantation develops CMV with increased clinical severity and risk of graft failure. The possibility of increased clinical severity and worse clinical outcomes by CMV co-infection should be considered in KTRs with PJP.

Incidence and outcomes of invasive fungal infection among solid organ transplant recipients: A population-based cohort study

BACKGROUND

Invasive fungal infection (IFI) in solid organ transplant (SOT) recipients is associated with significant morbidity and mortality. The long-term probability of post-transplant IFI is poorly understood.

METHODS

We conducted a population-based cohort study using linked administrative healthcare databases from Ontario, Canada, to determine the incidence rate; 1-, 5-, and 10-year cumulative probabilities of IFI; and post-IFI all-cause mortality in SOT recipients from 2002 to 2016. We also determined post-IFI, death-censored renal allograft failure.

RESULTS

We included 9326 SOT recipients (median follow-up: 5.35 years). Overall, the incidence of IFI was 8.3 per 1000 person-years. The 1-year cumulative probability of IFI was 7.4% for lung, 5.4% for heart, 1.8% for liver, 1.2% for kidney-pancreas, and 1.1% for kidney-only allograft recipients. Lung transplant recipients had the highest incidence rate and 10-year probability of IFI: 43.0 per 1000 person-years and 26.4%, respectively. The 1-year all-cause mortality rate after IFI was 34.3%. IFI significantly increased the risk of mortality in SOT recipients over the entire follow-up period (hazard ratio: 6.50, 95% CI: 5.69-7.42). The 1-year probability of death-censored renal allograft failure after IFI was 9.8%.

CONCLUSION

Long-term cumulative probability of IFI varies widely among SOT recipients. Lung transplantation was associated with the highest incidence of IFI with considerable 1-year all-cause mortality.

Variability of Pneumocystis jirovecii prophylaxis use among pediatric solid organ transplant providers

Pneumocystis jirovecii pneumonia (PJP) prophylaxis after pediatric solid organ transplant (SOT) is routinely recommended, but practice varies. Online survey was sent in 2018 to 707 members of the International Pediatric Transplant Association. A total of 105 responded, representing 47 institutions in 18 countries consisting of transplant physicians (66%), transplant surgeons (19%), nurse practitioners (6%), infectious disease physicians (5%), or pharmacists (4%). PJP prophylaxis was reported by 88%, while 12% did not routinely give prophylaxis. The majority not using PJP prophylaxis performed renal transplants (67%) citing low incidence of PJP (62%). Trimethoprim/sulfamethoxazole was first-line agent (95%). PJP prophylaxis for 4-6 months was the most frequent duration following kidney (48%, 27/56), liver (42%, 13/31), and heart (40%, 10/25) transplant. Abdominal multivisceral providers equally gave 10-12 months (47%) or lifelong (47%); most lung transplant providers gave lifelong prophylaxis (85%). Across all organs, 21% provided lifetime prophylaxis. After completion of prophylaxis, 32% do not restart for any reason; majority of the rest would restart for treatment of acute graft rejection. 83% reported no PJP cases in the prior 12 months; 14% reporting 1-5 infections. Only 3% reported a case of PJP infection on prophylaxis; none in SOT. PJP prophylaxis is routinely provided to pediatric SOT patients though practice and duration vary by center and organ type. Durations of 4-6 months were most common for renal, liver, and heart transplant recipients, while 10-12 months or lifelong prophylaxis were commonly reported for abdominal multivisceral recipients and most lung transplant recipients are given lifelong prophylaxis.

Pneumocystis Infection Outbreaks in Organ Transplantation Units in France: A Nation-Wide Survey

The burden of nosocomial Pneumocystis infections in transplantation units in France was evaluated through a retrospective survey. Over 12 years, 16 outbreaks occurred, including 13 among renal transplant recipients (RTRs). We performed Pneumocystis jirovecii genotyping in 5 outbreaks, which suggested that specific strains may have been selected by RTRs.

Pneumocystis jiroveci pneumonia in kidney and simultaneous pancreas kidney transplant recipients in the present era of routine post-transplant prophylaxis: risk factors and outcomes

BACKGROUND

The goal of this study was to identify predictors for development of Pneumocystis jirovecii pneumonia (PJP) in kidney and simultaneous kidney and pancreas transplant recipients in the present era of universal primary prophylaxis.

METHODS

We reviewed adult recipients of kidney transplant or simultaneous pancreas and kidney transplant at the University of Wisconsin between January 1, 1994 and December 31, 2016. Patients diagnosed with PJP during this time frame were included. Controls were randomly selected from among those whose post-transplant course was not complicated by PJP, matched on time since transplant through incidence density sampling with a 3:1 ratio.

RESULTS

28 (0.45%) of 6270 recipients developed PJP between 1994 and 2016. Median time since transplant was 4.6 years (interquartile range (IQR): 1.4-9.6 years). Affected recipients were older, had more HLA mismatches, and were more likely to have had BK viremia, CMV viremia and invasive fungal infections than matched controls. CMV viremia remained the only significant risk factor in multivariate analysis, and was a strong predictor (OR 6.27; p = 0.002). Ninety percent of the cases with prior CMV viremia had been diagnosed in the year preceding the diagnosis of PJP; among these, median time from diagnosis of CMV to diagnosis of PJP was 3.4 months (IQR: 1.74-11.5 months) and median peak CMV viral load prior to diagnosis of PJP was 3684.5 IU/mL (IQR: 1034-93,300 IU/mL). Additionally, 88.9% of patients with CMV in the preceding year had active infection at time of PJP diagnosis. Patient and graft survival were significantly worse at 2 years in recipients with PJP than our control group (42.4% vs. 88.5, and 37.9% vs. 79.9%; p < 0.001).

CONCLUSIONS

Despite the low overall incidence of PJP in the era of universal prophylaxis, outcomes are poor. We suggest extending or re-initiating PJP prophylaxis for at least 6 months in the setting of CMV viremia due to the relatively low risk of therapy and potential significant impact on disease prevention.