Abstract
An unusual case with kidney stones composed mainly of 1-methyluric acid is described. The patient, a Caucasian male of Celtic descent, reportedly drank at least eight cups of coffee per day and had a long history of rheumatoid arthritis, gouty attacks and renal colics—the latter attributed to nephrocalcinosis and analgesic nephropathy. He was treated with allopurinol. At 54 years, a bilateral nephrolithotomy was performed. Stone samples were analysed by thermogravimetry and infrared spectroscopy and reported to be 12–25% calcium oxalate, the remainder being organic uric acid-like material. Analysis of the extracts by HPLC confirmed that the organic material contained 67% of 1-methyluric acid and 33% of uric acid. Possible mechanisms leading to the precipitation of 1-methyluric acid from urine are discussed. We conclude that the high caffeine intake resulted in extremely elevated urinary concentrations of 1-methyluric acid favouring the formation of 1-methyluric acid stones.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Safranow K, Machoy Z (2005) Methylated purines in urinary stones. Clin Chem 51:1493–1498
Simmonds HA, Duley JA, Davies PM (1991) Analysis of purines and pyrimidines in blood, urine and other physiological fluids, chap 25. In: Hommes F (eds) Techniques in diagnostic human biochemical genetics: a laboratory manual. Wiley-Liss, New York, pp 397-424
Simmonds HA, Reiter S, Nishino T (1995) Hereditary xanthinuria, chap 54. In: Scriver CR, Beaudet AL, Sly WS, Valle D (eds) The metabolic and molecular basis of inherited disease, 7th edn. McGraw-Hill, New York, pp 1781–1797
Sahota A, Tischfield J, Kamatani N, Simmonds HA (2001) Adenine phosphoribosyltransferase deficiency: 2,8-dihydroxyadenine lithiasis, chap 108. In: Scriver CR, Beaudet AL, Sly WS, Valle D (eds) The metabolic and molecular basis of inherited disease, 8th edn. McGraw-Hill, New York, pp 2571–2584
Relling MV, Lin JS, Ayers GD, Evans WE (1992) Racial and gender differences in N-acetyltransferase, xanthine oxidase and CYP1A2 activities. Clin Pharmacol Ther 52:643–658
Reiter S, Simmonds HA, Zollner N, Braun S, Knedel M (1990) Demonstration of a combined deficiency of xanthine oxidase and aldehyde oxidase in xanthinuric patients not forming oxipurinol. Clin Chim Acta 187:221–234
Chalmers RA, Parker R, Simmonds HA, Snedden W, Watts RWE (1969) The conversion of 4-hydroxypyrazolo (3,4-d) pyrimidine (allopurinol) into 4,6-dihydroxypyrazolo (3,4-d) pyrimidine (oxipurinol) in vivo in the absence of xanthine–oxygen oxidoreductase. Biochem J 112:527–532
Hanzal RF, Myers VC (1932) The excretion of methyl uric acids after the ingestion of methylated xanthines. J Biol Chem 97:LXIX-LXX
Ullrich D, Compagnone D, Munch B, Brandes A, Hille H, Bircher J (1992) Urinary caffeine metabolites in man. Age-dependent changes and pattern in various clinical situations. Eur J Clin Pharmacol 43:167–172
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Davies, P.M., Fairbanks, L.D., Safranow, K. et al. An unusual patient with kidney stones composed of 1-methyluric acid. Urol Res 34, 58–60 (2006). https://doi.org/10.1007/s00240-005-0002-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00240-005-0002-8