Bacterial pneumonia in kidney transplant recipients

Abstract

Bacterial pathogens are the most frequent cause of pneumonia after transplantation. Early after transplantation, recipients are at higher risk for nosocomial infections. The most commonly encountered pathogens during this period are gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa …), but gram-positive coccus such as Staphylococcus aureus or Streptococcus pneumoniae and anaerobic bacteria can also be found. Empirical antibiotic therapy should be guided by previous colonisation of the recipient and bacterial resistance pattern in the hospital. Six months after transplantation, pneumonias are mostly due to community-acquired bacteria (S. pneumonia, H. influenza, Mycoplasma, Chlamydia and others). Opportunistic pathogens take advantage of the state of immunosuppression which is usually highest from one to six months after transplantation. During this period, but also occurring many years later in the setting of a chronically depressed immune system, bacterial pathogens with low intrinsic virulence can cause pneumonia. The diagnosis of pneumonia caused by opportunistic pathogens can be challenging. The delay in diagnosis preventing the early instauration of adequate treatment in kidney transplant recipients with a depressed immune system, frequently coupled with co-morbid conditions and a state of frailty, will affect prognosis and outcome, increasing morbidity and mortality. This review will focus on the most common opportunistic bacterial pathogens causing pneumonia in kidney transplant recipients: Legionella, Nocardia, Mycobacterium tuberculosis/nontuberculous, and Rhodococcus. Recognition of their specificities in the setting of immunosuppression will allow early diagnosis, crucial for initiation of effective therapy and successful outcome. Interactions with immunosuppressive therapy should be considered as well as reducing immunosuppression if necessary.

Coinfection of Mycobacterium malmoense and Mycobacterium chimaera in a kidney transplant recipient: A case report and review of the literature

“…Although they are uncommon causes of disease in the general population, they cause more often opportunistic infections in immunocompromised patients. [1][2][3][4][5][6][7][8] Among SOT recipients, skin and soft tissue disease is the most frequent NTM infection. In KTR, NTM cause more often cutaneous or disseminated infections, followed by osteoarticular disease and then pleuropulmonary infections.…”

“…Establishing the diagnosis of NTM infection is often difficult because clinical symptoms are nonspecific. 1,2,8 In addition, NTM can be found as an environmental or laboratory contaminant and a positive culture does not necessarily indicate infection. 3,4,7 In 2007, the American Thoracic Society (ATS) published clinical, radiographic, and microbiologic criteria required for diagnosis of NTM pulmonary disease.…”

“…1,2,5 Diagnostic at the species level and antimicrobial susceptibility testing (AST) are complex, requiring molecular probes such as 16S rDNA sequencing and MALDI-TOF mass spectrometry, and high expertise of the laboratory evaluating NTM species. 2,4,8 ATS guidelines are available for the treatment of NTM infections in the general population. 6 In SOT recipients, there have been no randomized trials of NTM infections treatment.…”

Approach to Transplant Infectious Diseases in the Emergency Department

“…On chest radiography, infiltrates may be absent or minimal in the setting of pneumonia. [20] Pyuria can be absent despite a urinary tract infection. A paucity of classic findings indicating infection should not dissuade an emergency physician from further clinical investigation if the index of suspicion for infection is high based on a patient’s level of immunosuppression.…”

A New Indication for Pneumococcal Vaccination?

“…Interestingly, the impact of a lower eGFR was most marked among Canadian patients aged 18 to 54 years, a group not studied in the report by Ishigami et al 3 Among kidney transplant recipients, pneumococcal vaccination is recommended, but S pneumoniae is still a great threat. 11 There are 2 primary outcome metrics that Ishigami et al addressed in their report. 3 The first was the incremental cost-effective ratio (ICER), which is the critical value used in cost-effectiveness analysis (CEA) studies.…”