title: Serum procalcitonin levels in patients with myeloperoxidase-antineutrophil cytoplasmic antibodies-associated glomerulonephritis.
abstract: BACKGROUND
  High serum procalcitonin (PCT) levels (≥0.5 ng/mL) commonly occur with systemic bacterial and fungal infections. Although several studies suggested that measuring serum PCT levels may serve as a useful marker to distinguish between active antineutrophil cytoplasmic antibodies (ANCA)-associated diseases and invasive infections, there is no information on PCT in myeloperoxidase (MPO)-ANCA-associated glomerulonephritis.
  
  
  METHODS
  The authors measured serum PCT concentrations before initiation of immunosuppressive therapy in 67 patients with biopsy-proven MPO-ANCA-associated glomerulonephritis. The authors compared complications and clinicopathological parameters between patients with serum PCT levels of <0.5 ng/mL (group A: 58 patients) and ≥0.5 ng/mL (group B: 9 patients).
  
  
  RESULTS
  All 58 patients in group A did not show any clinical sign of systemic infection. On the other hand, 3 of 9 patients in group B had bacterial or fungal infections of the respiratory or urinary tact. One patient had a history of chronic urinary tract infection. In the remaining 5 patients in group B, there were 3 patients with concurrent malignancies and 1 postoperative patient with malignancy. Another in group B had a long history of interstitial pneumonia of unknown origin and severe renal insufficiency. Serum levels of C-reactive protein and creatinine were significantly higher in group B than in group A.
  
  
  CONCLUSIONS
  In patients with MPO-ANCA-associated glomerulonephritis, serum PCT levels of ≥0.5 ng/mL are recommended as cutoff for consideration of bacterial and fungal infections. Elevated serum PCT levels could also be observed in some patients with severe injury of the kidneys and/or lungs in the absence of infection.
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan. Electronic address: komatsud@med.akita-u.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Komatsuda
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Omokawa
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Sato
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Togashi
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Okuyama
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Sawada
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Wakui
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood / Q000378:metabolism*; D001327:Autoimmune Diseases / Q000097:blood / Q000150:complications / Q000175:diagnosis; D001424:Bacterial Infections / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D003404:Creatinine / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005921:Glomerulonephritis / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D007165:Immunosuppression Therapy; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D009195:Peroxidase / Q000378:metabolism; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000175:diagnosis / Q000209:etiology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D003404:Creatinine; D009195:Peroxidase; D015740:Calcitonin Gene-Related Peptide