Circulating bacterial-derived DNA fragments and markers of inflammation in chronic hemodialysis patients.
OBJECTIVE
Bacterial-derived DNA fragments (BDNAs) have been shown to be present in dialysis fluid, to pass through dialyzer membranes, and to induce IL-6 (IL-6) in mononuclear cells. The present study aimed at assessing the eventual presence of BDNAs in the blood of hemodialysis (HD) patients and if this is associated with markers of chronic inflammation.


METHODS
Fifty-eight HD patients and 30 controls were included in the study. A blood sample was collected from a peripheral vein and from the central venous catheter (CVC) or the arteriovenous fistula (AVF) and examined for presence of BDNAs by 16S rRNA gene PCR amplification, bacterial growth, and measurement of C-reactive protein and IL-6. Thirty minutes after the start of HD, a sample of dialysis fluid was collected before the entry into and at the exit of the dialyzer and examined for presence of BDNAs.


RESULTS
Controls had negative blood cultures and absence of blood BDNAs. All HD patients had negative blood cultures, but in 12 (20.7%), BDNAs were present in the whole blood. In five of the latter, BDNAs were also found in the dialysis fluid. C-reactive protein serum levels (mg/L) were significantly higher in patients with than in those without BDNAs. Likewise, IL-6 serum levels (pg/ml) were significantly higher in patients with BDNA than in those without.


CONCLUSIONS
Circulating BDNAs are associated with higher levels of C-reactive protein and IL-6 in HD patients.
Bossola
Maurizio
M
Istituto di Clinica Chirurgica, Servizio Emodialisi, Università Cattolica del Sacro Cuore, Largo A. Gemelli, 8-00168 Roma, Italia. maubosso@tin.it
Sanguinetti
Maurizio
M
Scribano
Donata
D
Zuppi
Cecilia
C
Giungi
Stefania
S
Luciani
Giovanna
G
Torelli
Riccardo
R
Posteraro
Brunella
B
Fadda
Giovanni
G
Tazza
Luigi
L
D000368:Aged; D001166:Arteriovenous Shunt, Surgical; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D016022:Case-Control Studies; D002405:Catheterization, Central Venous / Q000295:instrumentation; D002408:Catheters, Indwelling; D004269:DNA, Bacterial / Q000097:blood*; D015314:Dialysis Solutions / Q000032:analysis; D004340:Drug Contamination; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000382:microbiology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012336:RNA, Ribosomal, 16S / Q000097:blood*; D006435:Renal Dialysis; D015854:Up-Regulation
D015415:Biomarkers; D004269:DNA, Bacterial; D015314:Dialysis Solutions; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D012336:RNA, Ribosomal, 16S; D002097:C-Reactive Protein