Serum amyloid A: a novel serum marker for the detection of systemic inflammatory response in cystitis.
OBJECTIVE
We compared serum amyloid A (SAA) protein, C-reactive protein (CRP), interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha as inflammatory markers for pyelonephritis and cystitis.


METHODS
SAA, CRP, IL-6 and TNF-alpha were determined in serum from 69 consecutive patients with acute pyelonephritis (37) and acute cystitis (32) on admission to an infectious disease clinic and on examination at a primary health care center, respectively. Healthy blood donors served as controls.


RESULTS
SAA showed a systemic inflammatory response in cystitis in 90% of patients compared with 23%, 42% and 0% for CRP, IL-6 and TNF-alpha, respectively. SAA and CRP had equally high efficiencies (0.96 and 0.94, respectively) for discriminating between pyelonephritis and cystitis while efficiencies for IL-6 (0.85) and TNF-alpha (0.91) were lower.


CONCLUSIONS
SAA is a sensitive systemic marker in cystitis but is still useful in detecting pyelonephritis.
Lannergard
A
A
Department of Medical Sciences, Infectious Diseases, Uppsala University Hospital, S-751 85 Uppsala, Sweden. anders.lannergard@medicin.uas.lul.se
Friman
G
G
Larsson
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D003556:Cystitis / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000175:diagnosis; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011704:Pyelonephritis / Q000175:diagnosis; D000685:Serum Amyloid A Protein / Q000032:analysis*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*
D015415:Biomarkers; D015850:Interleukin-6; D000685:Serum Amyloid A Protein; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein