Life-long antimicrobial therapy: where is the evidence?

The decision to prescribe long-term or 'life-long' antibiotics in patients requires careful consideration by the treating clinician. While several guidelines exist to help assist in this decision, the long-term consequences are yet to be well studied. In this review, we aim to provide a summary of the available evidence for patient populations where long-term antibiotic therapy is currently recommended in clinical practice. We will also discuss the pitfalls of this approach, including medication adverse effects, economic cost and any possible contribution to the emerging epidemic of microbial resistance.

Hypercalcaemia preceding diagnosis of Pneumocystis jirovecii pneumonia in renal transplant recipients

BACKGROUND

The overall incidence of Pneumocystis jirovecii pneumonia (PJP) in solid organ transplant recipients is 5-15%. A timely diagnosis of PJP is difficult and relies on imaging and detection of the organism.

METHODS

We present a case series of four patients displaying hypercalcaemia with an eventual diagnosis of PJP and document the management of the outbreak with a multidisciplinary team approach. We discuss the underlying pathophysiology and previous reports of hypercalcaemia preceding a diagnosis of PJP. We also reviewed the evidence concerning PJP diagnosis and treatment.

RESULTS

Within our renal transplant cohort, four patients presented within 7 months with hypercalcaemia followed by an eventual diagnosis of PJP. We measured their corrected calcium, parathyroid hormone (PTH), 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] and 25-hydroxycholecalciferol [25(OH)D] levels at admission and following treatment of PJP. All four patients diagnosed with PJP were 4-20 years post-transplantation. Three of the four patients demonstrated PTH-independent hypercalcaemia (corrected calcium >3.0 mmol/L). The presence of high 1,25(OH)2D3 and low 25(OH)D levels suggest negation of the negative feedback mechanism possibly due to an extrarenal source; in this case, the alveolar macrophages. All four patients had resolution of their hypercalcaemia after treatment of PJP.

CONCLUSIONS

Given the outbreak of PJP in our renal transplant cohort, and based on previous experience from other units nationally, we implemented cohort-wide prophylaxis with trimethoprim-sulphamethoxazole for 12 months in consultation with our local infectious diseases unit. Within this period there have been no further local cases of PJP.

High Pneumocystis jirovecii colonization rate among haemodialysis patients

Haemodialysis patients have been found to have an increased risk of developing Pneumocystis pneumonia (PcP) compared to the control population. To the best of our knowledge, no data are available on pulmonary colonization with Pneumocystis jirovecii in haemodialysis patients; therefore, the aim of this study was to determine the prevalence of pulmonary colonization with P. jirovecii in haemodialysis patients, and to find the related risk factors. Induced sputa of 62 haemodialysis patients were investigated using quantitative polymerase chain reaction for the presence of P. jirovecii. 20.9% of the patients were colonized with P. jirovecii and 46.2% of whom had CD4 cell counts below 400/μl. There was no significant correlation between colonization and time on dialysis treatment. As haemodialysis patients seem to be at higher risk of PcP than the general population, doctors should be aware of the high rate of P. jirovecii colonization amongst them. Furthermore, colonized patients remain a potential source of transmission of P. jirovecii to other patients or to health care workers.

Clinical Course, Radiological Manifestations, and Outcome of Pneumocystis jirovecii Pneumonia in HIV Patients and Renal Transplant Recipients

Background

Pneumocystis jirovecii pneumonia (PCP) is a frequent opportunistic infection in immunocompromised patients. In literature, presentation and outcome of PCP differs between patients with human immunodeficiency virus (HIV) infection and renal transplant recipients (RTRs).

Methods

We conducted a cross-sectional study of patients with PCP based on the HIV and renal transplant registries at our institution. Radiological and clinical data from all confirmed PCP cases between 2005 and 2012 were compared.

Results

Forty patients were included: 16 with HIV and 24 RTRs. Radiologically, HIV patients had significantly more areas of diffuse lung affection (81% HIV vs. 25% RTR; p = 0.02), more ground glass nodules 5–10 mm (69% vs. 4%; p = <0.001) and enlarged hilar lymph nodes were found only in HIV patients (44%). Cough and dyspnea were the most common clinical signs (>80%) in both groups. Duration from illness onset to hospital presentation was longer in the HIV patients (median of 18 vs. 10 days (p = 0.02)), implying a less fulminant clinical course. Sixty percent of PCP cases in RTRs occurred >12 months after transplantation. Lengths of hospitalization, admission rates to the intensive care unit, and requirements for mechanical ventilation were similar. Outcome in both groups was favourable.

Conclusions

While important differences in radiological presentation of PCP between HIV patients and RTRs were found, clinical presentation was similar. PCP only rarely presented with fulminant respiratory symptoms requiring ICU admission, with similar results and outcomes for HIV patients and RTRs. Early diagnosis and treatment is mandatory for clinical success.

Molecular epidemiologic analysis of a Pneumocystis pneumonia outbreak among renal transplant patients

Between 18 November and 3 December 2011, five renal transplant patients at the Department of Nephrology, Toho University Omori Medical Centre, Tokyo, were diagnosed with Pneumocystis pneumonia (PCP). We used molecular epidemiologic methods to determine whether the patients were infected with the same strain of Pneumocystis jirovecii. DNA extracted from the residual bronchoalveolar lavage fluid from the five outbreak cases and from another 20 cases of PCP between 2007 and 2014 were used for multilocus sequence typing to compare the genetic similarity of the P. jirovecii. DNA base sequencing by the Sanger method showed some regions where two bases overlapped and could not be defined. A next-generation sequencer was used to analyse the types and ratios of these overlapping bases. DNA base sequences of P. jirovecii in the bronchoalveolar lavage fluid from four of the five PCP patients in the 2011 outbreak and from another two renal transplant patients who developed PCP in 2013 were highly homologous. The Sanger method revealed 14 genomic regions where two differing DNA bases overlapped and could not be identified. Analyses of the overlapping bases by a next-generation sequencer revealed that the differing types of base were present in almost identical ratios. There is a strong possibility that the PCP outbreak at the Toho University Omori Medical Centre was caused by the same strain of P. jirovecii. Two different types of base present in some regions may be due to P. jirovecii's being a diploid species.

Molecular detection of Pneumocystis jirovecii using polymerase chain reaction in immunocompromised patients with pulmonary disorders in northeast of Iran

Background and Purpose:

Pneumocystis pneumonia, caused by Pneumocystis jirovecii, is a fatal disease threatening patients with AIDS or immunosuppression. Assessment of colonization in these patients is of great significance, since it can lead to severe pulmonary disorders. Considering the scarcity of published reports on Pneumocystis jirovecii isolates from patients in Mashhad, Iran, we aimed to evaluate pneumocystis colonization in individuals with different pulmonary disorders.

Materials and Methods:

We used nested polymerase chain reaction (PCR) method to amplify mitochondrial large subunit-ribosomal ribonucleic acid (mtLSU-rRNA) gene in 60 bronchoalveolar lavage (BAL) samples, obtained from patients, referring to the Department of Internal Medicine (Pulmonary Diseases Section) at Imam Reza Hospital, affiliated to Mashhad University of Medical Sciences, Mashhad, Iran.

Results:

DNA of Pneumocystis jirovecii was detected in 10 out of 60 BAL samples (16.66%) via nested PCR method.

Conclusion:

According to the present findings, the colonization rate of Pneumocystis jirovecii was similar to the rates reported in other similar studies in Iran.

Pneumocystis pneumonia (PCP) and Pneumocystis jirovecii carriage in renal transplantation patients: a single-centre experience

BACKGROUND

The Pneumocystis pneumonia is an increasing problem in transplanted patients: up to 25% suffer from Pneumocystis pneumonia, occurring during the first 6 months after transplantation.

METHODS

From 2001 to 2009, we investigated 21 patients with pneumonia after renal transplantation for the presence of Pneumocystis jirovecii. The laboratory diagnosis was established by Grocott and Giemsa staining methods and Pneumocystis-specific mitochondrial transcribed large subunit nested polymerase chain reaction (PCR). The PCR was also used for the differentiation of Pneumocystis pneumonia from Pneumocystis carriage.

RESULTS

Of 21 patients, 7 had a Pneumocystis pneumonia, 6 were Pneumocystis carriers and 8 patients were negative. Four out of seven Pneumocystis pneumonia patients and two out of six patients with Pneumocystis carriage had a delayed graft function. An acute cytomegalovirus infection after transplantation was not detectable in the patients with Pneumocystis pneumonia, but in three patients with Pneumocystis carriage.

CONCLUSIONS

Pneumocystis pneumonia was present in 33.3% of transplanted patients with suspected pneumonia. An association between acute rejection or co-infections and Pneumocystis pneumonia or carriage in patients after renal transplantation cannot be excluded. In three out of seven Pneumocystis pneumonia patients, an overlapping of hospitalisation times and an onset of Pneumocystis pneumonia 6 months after transplantation was found. Thus, person-to-person transmission seems probable in these cases.

Higher prevalence of nephropathy in young Roma females compared with non-Roma females

OBJECTIVES

Ethnic differences in the prevalence of various chronic diseases, including end-stage renal disease, have been previously reported. Surprisingly, data focusing on the lower grade of chronic kidney disease (CKD) are scarce. Thus, the aim of this study was to explore differences in the prevalence of nephropathy between the Roma and non-Roma populations.

METHODS

Data from the cross-sectional population based HepaMeta study conducted in Slovakia were used. Nephropathy was defined as: a known history of any kidney disease; or the presence of proteinuria/hematuria; or glomerular filtration rate (GFR) < 60 ml/min. The odds ratio for the prevalence of nephropathy was calculated using binary logistic regression.

RESULTS

In an age-adjusted model, Roma females had OR of 1.56 for having nephropathy over non-Roma females (OR 1.56; 95% CI 1.01-2.42; p < 0.05). In addition, Roma females had a significantly lower GFR (mean difference 3.4 ml/min, t = -3.58, p < 0.001); all female patients with proteinuria were Roma.

CONCLUSIONS

This cross-sectional study on the young general population found that Roma females have half-higher odds for nephropathy than non-Roma females. Therefore, to prevent risks we should focus on searching for ethnic, social and medical determinants of CKD. Interventions to decrease the incidence of CKD in the target population should also address ethnic inequalities as well as female gender.

Low incidence of Pneumocystis jirovecii pneumonia in an unprophylaxed liver transplant cohort

BACKGROUND

Liver transplant recipients are managed with a range of immunosuppressive regimens that place them at heightened risk of life-threatening opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). No routine PJP prophylaxis is used at out institution. We reviewed the incidence of PJP in this cohort of unprophylaxed liver transplant recipients.

METHODS

We examined all liver transplants performed between January 2000 and January 2012 in Ireland's National Liver Transplant Centre, St. Vincent's University Hospital, Dublin. Cases were identified through a computerized database and through the histopathology and microbiology registration system. The diagnosis of PJP was confirmed by identification of Pneumocystis cysts in bronchoalveolar lavage (BAL) fluid or on autopsy specimens using Grocott-Gomori methenamine-silver nitrate or modified Wright-Giemsa staining methods.

RESULTS

During the study period, 687 liver transplants were performed. We found 7 cases of PJP with an incidence rate of 0.84 per 1000 person transplant years. Five cases occurred within 12 months of transplant with 2 cases occurring at 56 and 60 months, respectively. Two cases were diagnosed at postmortem; 1 previously had negative cytology from BAL, while the other could not be bronchoscoped because of rapid deterioration in the clinical condition. Three of the 5 treated patients died.

CONCLUSIONS

The incidence of PJP in this cohort was very low, but the case fatality rate was high. Two cases occurred well after the usual recommended period of prophylaxis. In institutions with a very low risk of infection, targeted rather than universal prophylaxis may be reasonable.

Pneumocystis jirovecii multilocus genotyping profiles in Northern Ireland

Pneumocystis jirovecii causes pneumonia, a severe opportunistic infection in immunosuppressed patients that has both person-to-person airborne transmission and environmental transmission as important routes of infection. An increasing incidence of P. jirovecii in Northern Ireland prompted a detailed epidemiological and molecular review that included enhanced surveillance on all lower respiratory specimens. Genotyping of these P. jirovecii positive specimens was undertaken using multiple locus sequence typing (MLST) targeting known variable regions of the P. jirovecii genome. Multiple circulating types were found among all patient risk categories. However, a predominance of one MLST type was found in a P. jirovecii outbreak amongst the renal transplant population. Our results demonstrate the diversity of P. jirovecii strains amongst the local immunosuppressed cohort and highlight the importance of genotyping in the investigation of common sources of P. jirovecii amongst immunosuppressed patients.

Nebulized pentamidine-induced acute renal allograft dysfunction

Acute kidney injury (AKI) is a recognised complication of intravenous pentamidine therapy. A direct nephrotoxic effect leading to acute tubular necrosis has been postulated. We report a case of severe renal allograft dysfunction due to nebulised pentamidine. The patient presented with repeated episodes of AKI without obvious cause and acute tubular necrosis only on renal histology. Nebulised pentamidine was used monthly as prophylaxis for Pneumocystis jirovecii pneumonia, and administration preceded the creatinine rise on each occasion. Graft function stabilised following discontinuation of the drug. This is the first report of nebulized pentamidine-induced reversible nephrotoxicity in a kidney allograft. This diagnosis should be considered in a case of unexplained acute renal allograft dysfunction.