Chlamydia pneumoniae infection and ischemic heart disease in hemodialysis patients

Ischemic heart disease and other atherosclerotic complications are the prominent causes of death among hemodialyzed end-stage renal disease (ESRD) patients and renal transplant recipients. Numerous articles in recent years have raised the possibility of an infective factor, especially Chlamydia pneumoniae, in the development of atherosclerosis and its complications. The aim of this study was to assess the incidence of chronic C pneumoniae infection and its association with ischemic heart disease and atherosclerosis in a population of patients with ESRD awaiting renal transplantation.

The studied group consisted of 164 subjects: 99 ESRD patients (heart disease [HD] group) who were hospitalized for vascular access creation (27), pretransplantation nephrectomy (47), or kidney transplantation (25), and a control group of 65 subjects consisting of 50 healthy blood donors and 15 multiorgan donors. C pneumoniae was detected in vascular wall fragments, kidney biopsy specimens and peripheral blood monocytes using real time polymerase chain reaction (PCR). Serum immunoglobulin IgG and IgA anti-C pneumoniae antibodies were detected using Enzyme-linked immunosorbent assay (ELISA) and a lipid profile (cholesterol, high-density lipoprotein [HDL], low-density lipoprotein [LDL], and triglycerides [TG]) was obtained. Data on cardiovascular disease events, smoking history, diabetes, hypertension, cause, and length of renal failure were collected and analyzed. The existence of atherosclerotic lesions was detected using ultrasound (US) Doppler examination of aortic bifurcation. Chronic C pneumoniae infection was diagnosed on the basis of detection of both IgA and IgG antibodies and/or the detection of C pneumoniae DNA in vascular wall fragments or peripheral blood monocytes. After a follow-up of 32 months, data on cardiovascular events and patient history were collected again.

Chronic C pneumoniae infection affected 46.5% (46/99) of HD patients and 9% (6/65) of controls (P < .05). Among HD patients, 26.3% (26/99) had ischemic heart disease (IHD) versus 6% in the control group. Among C pneumoniae-infected HD patients, IHD was more frequent (39.1%) than in noninfected HD patients (15%; P < .05). Within the 32-month observation period of the HD group, cardiac pain was observed in 11 (24%; 11/46) infected patients versus 3 (5.7%; 3/53) patients without C pneumoniae infection (P < .05). Exacerbation of previously diagnosed IHD was observed in 8 (44%; 8/18) cases in the C pneumoniae-infected group versus 0 (0%; 0/8) in the uninfected patients (P < .05).

Chronic C pneumoniae infection affects hemodialysis patients more frequently than healthy subjects. Hemodialysis patients with C pneumoniae infection are at the greater risk of exacerbation of existing IHD.