Abstract
The relationship between the levels of serum cystatin C and the prognostic stages of IgA nephropathy was determined in a multicenter trial in Japan. The levels of serum cystatin C in patients with IgA nephropathy were measured using the Dade Behring N Latex Cystain C assay. In 1995, the Joint Committee of the Special Study Group on Progressive Glomerular Diseases, Ministry of Health and Welfare of Japan, and the Japanese Society of Nephropathy reported four prognostic stages. These are: good prognosis group (Group I), relatively good prognosis group (Group II), relatively poor prognosis group (Group III), and poor prognosis group (Group IV), for this disease. Three‐hundred and six patients with IgA nephropathy and other glomerular diseases were examined. There were no significant changes in the levels of serum creatinine (Cr) or creatinine clearance (CCr) between Group I and Group II. The mean levels of serum cystatin C in Group II were significantly higher than those in Group I (P < 0.05). The mean levels of serum cystatin C in Group III or IV were significantly higher than those in Group I (P < 0.001, P < 0.005, respectively). These suggest that the measurement of serum cystatin C may predict the prognostic stages of patients with IgA nephropathy prior to renal biopsy. J. Clin. Lab. Anal. 15:25–29, 2001. © 2001 Wiley‐Liss, Inc.
Keywords: serum cystatin C, prognostic stage, IgA nephropathy
REFERENCES
- 1. Sakai H, Abe K, Kobayashi Y, et al. 1995. Clinical guidelines of IgA nephropathy. Jpn J Nephrol 37:417–421. [PubMed] [Google Scholar]
- 2. Tomino Y, Suzuki S, Imai H, et al. 2000. Measurement of serum IgA and C3 may predict the diagnosis of patients with IgA nephropathy prior to renal biopsy. J Clin Lab Anal 14:220–223. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Barrett AJ, Davies ME, Grubb A. 1984. The place of human γ‐trace (cystein C) amongst the cystein proteinase inhibitors. Biochem Biophys Res Commun 120:631–636. [DOI] [PubMed] [Google Scholar]
- 4. Grubb A, Lofberg H. 1982. Human γ‐trace, a basic microprotein: amino acid sequence and presence in the adenohypophysis. Proc Natl Acad Aci U S A 79:3024–3027. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Barret AJ, Fritz H, Grubb A, et al. 1986. Nomenclature and classification of the proteins homologous with chicken cystatin. (abstr). Biochem J 236:312. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Simonsen O, Grubb A, Thysell. 1985. The blood serum concentration of cystatin C (γ‐trace) as a measure of the glomerular filtration rate. Scand J Clin Lab Invest 45:97–101. [DOI] [PubMed] [Google Scholar]
- 7. Grubb A, Simonsen O, Sturtfelt G, Truedsson L, Thysell H. 1985. Serum concentration of cystatin C, factor D and β2‐microglobumin as a measure of glomerular filtration rate. Acta Med Scand 218:499–503. [DOI] [PubMed] [Google Scholar]
- 8. Erlandsen EJ, Randers E, Kristensen JH. 1999. Evaluation of the Dade Behring Latex Cystatin C assay on the Dade Behring Nephelometer System. Scand J Clin Lab Invst 59:1–8. [DOI] [PubMed] [Google Scholar]
- 9. Ohara T, Nakai K, Orisaka M, Itoh T, Saito K, Itoh K. 2000. A trial for establishing reference intervals of serum cystatin C in normal individuals. Medicine and Pharmacology 43:835–844 (in Japanese). [Google Scholar]
- 10. Fink PC, Romer M, Haeckel R, et al. 1989. Measurement of proteins with the Behring nephelometer. aA multicenter evaluation. J Clin Chem Clin Biochem 27:261–276. [PubMed] [Google Scholar]
- 11. Zweig MH, Campbell G. 1993. Receiver‐operating characteristic (ROC) plots: a fundamental evaluation tool in clinical medicine. Clin Chem 39:561–577. [PubMed] [Google Scholar]
- 12. Newman DJ, Thakkar H, Edwards RG, et al. 1995. Serum cystatin C measured by automated immunoassay: a more sensitive marker of changes in GFR than serum creatinine. Kidney Int 47:312–318. [DOI] [PubMed] [Google Scholar]