Hydroxyl apatite stones

Posted by Kristin on May 12, 1999 at 10:08:39
I have the results on my kidney stone, and it turns out to be homogeneously nucleated, 75% hydroxyl apatite. The rest was a mix of carbonate apatite and oxolate. It also demonstrated a protein matrix. My question is, in the absence of any history of UTI's, what other conditions can cause this type of stone? Can it be purely dietary? I will be seeing a nephrologist to check out the metabolic possibilties; any knowledge I can gain before that time would be greatly appreciated. Thanks!  Kristin

Posted by HFHS M.D.-AK on May 12, 1999 at 14:52:23
Dear Kristin,
Infectious stones are always struvite, Magnesium Ammonium Phosphate Hexahydrate.  To directly answer your question, yes, your stone is most likely do to a combination of diet and poor fluid intake.  Your clinical history may help to determine the cause of stone formation.  The inherited disorders that often cause stones are primary hyperoxaluria, cystinuria, and renal tubular acidosis.  Idiopathic stone formation and uric acid lithiasis are more common in males, whereas primary hyperparathyroidism and RTA are more common in females
Urinary excretion of calcium, phosphorus, oxalate, and uric acid is a function of dietary intake.  Due to your stone analysis, a dietary association is most likely. If this is your first stone,  I think a limited metabolic work-up with your nephrologist or urologist might be helpful.  More than likely, they will encourage you to increase your fluid intake and watch for foods high in oxalate
This information is provided for general medical educational purposes only.  Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition.  More individualized care is available at the Henry Ford Hospital and its satellites (1 800 653-6568).
Sincerely,
HFHS M.D.-AK
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