CHICAGO – Patients with end-stage renal disease have sharply elevated rates of hospitalization for pneumonia throughout the renal transplantation trajectory, researchers reported at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
The findings underscore the importance of vaccinating this group against pneumococcal and other diseases, lead investigator Lise Haubjerg Nielsen recommended in an interview. Pneumonia "is a big economic burden for society and it is a huge [source of] mortality for these patients."
In a Danish nationwide population-based cohort study among more than 90,000 individuals, those with end-stage renal disease (ESRD) had an 8- to 14-fold higher incidence of such hospitalization, depending on whether they were wait-listed, posttransplant, or post–graft failure, when compared with their counterparts in the general population.
About one-third of the posttransplant group was hospitalized for pneumonia. Male sex and older age were among the significant risk factors for pneumonia hospitalization at this stage. On the other hand, risk fell after the first year posttransplant.
The marked increase in posttransplant risk was expected, given patients’ use of immunosuppressants, according to Ms. Nielsen, who is a medical student undertaking a research year in the department of infectious diseases at Aarhus University Hospital, Skejby. However, the fact that the elevations seen before and after transplantation were even greater was surprising, she said at the meeting, which was sponsored by the American Society for Microbiology.
The increase in pretransplant risk was probably caused by patients’ uremic state, while that post–graft failure "could also be just [a reflection of] these patients being more sick than the general population," she speculated.
The investigators analyzed data from the Danish National Hospital Registry, identifying all hospitalizations since 1977 having a discharge diagnosis of pneumonia, regardless of whether the infection was community or hospital acquired.
They assessed first hospitalizations for pneumonia (excluding those caused by Pneumocystis jiroveci) occurring during 1990-2009. Patients with ESRD who were wait-listed for and/or underwent transplantation were matched by age and sex with up to 19 unaffected individuals from the general population. Analyses were based on 4,973 individuals with and 85,899 individuals without ESRD.
The incidence of first pneumonia hospitalization was 46, 32, and 63 per 1,000 person-years among wait-listed patients, renal transplant recipients, and patients who experienced graft loss, respectively.
These groups had corresponding 10-, 9, and 14-fold increases in the incidence of such hospitalization compared with the general population, according to Ms. Nielsen.
In an analysis of risk factors among the renal transplant recipients, the adjusted incidence rate of pneumonia hospitalization was significantly higher for men; patients aged 50 years or older; those who underwent 1-3 years of dialysis pretransplantation versus none; and those whose renal disease was associated with diabetes, chronic interstitial nephritis, or polycystic kidney disease as compared with glomerulonephritis. The risk of pneumonia hospitalization was significantly lower for those who were at least 1 year out from transplantation.
Ms. Nielsen reported having no conflicts of interest.