SEARCH · PubMed Health

Results for “Nephrolithiasis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

PubMed1996

The abnormal red-cell oxalate transport is a risk factor for idiopathic calcium nephrolithiasis: a prospective study.

An abnormal erythrocyte transmembrane oxalate flux was described in recurrent idiopathic calcium nephrolithiasis. To verify whether it might represent a risk marker of renal stone disease, two prospective studies were carried out. One hundred ninety patients with idiopathic calcium nephrolithiasis who were enrolled at their first episode of lithiasis during the period 1984 to 1986, form the basis of the first prospective study. The impact of erythrocyte oxalate transport anomaly, gender, familial occurrence of nephrolithiasis, hypercalciuria, hyperoxaluria, and hyperuricosuria on stone recurrence by both bivariate and multivariate analysis of frequencies was assessed. The predictive value of the erythrocyte anomaly for a patient's becoming a stone former was also assessed in five nephrolithiasis families. Recurrence occurred in 57.9% of patients; this was significantly associated with the erythrocyte anomaly, hyperoxaluria, and male gender. However, when using multivariate analysis, only gender and the erythrocyte anomaly were statistically significant and were independent predictors of recurrency. The probability of stone recurrency predicted by the logistic model ranged from 30.1% for women with normal erythrocyte oxalate transport, to 73.4% for men with the erythrocyte anomaly. The family follow-up showed that only subjects with the erythrocyte abnormality become renal stone-formers in the 8-yr survey. By showing the predictive value of the erythrocyte oxalate anomaly for recurrent calcium nephrolithiasis, our findings support the notion that this anomaly is a risk factor in renal stone disease.

Adolescent↗

PubMed2000

Increased incidence of indinavir nephrolithiasis in patients with hepatitis B or C virus infection.

MATERIALS AND METHODS: A HIV-1 patient database was scanned in March 1998, and 750 patients were identified who had received HAART including indinavir. Of these, 28 cases had nephrolithiasis; and 85 asymptomatic indinavir-treated patients were randomly selected as controls. The characteristics of cases and controls were compared by analysis of variance for quantitative parameters and by Fisher's exact test for classes. RESULTS: We observed a significant increase in the incidence of nephrolithiasis in patients co-infected with HIV-1 and either hepatitis C virus (HCV) (HCV RNA-positive) or hepatitis B virus (HBV) (HBs antigen-positive) (odds ratio and 95% confidence intervals: 2.8 and 1.1-7.7), whereas no significant differences were demonstrated between cases and controls with regard to age (42.4 +/- 8.0 versus 39.8 +/- 9.8 years), sex (male patients 70.4 versus 74.1%), duration of HIV-1 infection (8.6 +/- 3.1 versus 7.7 +/- 4.0 years), duration of indinavir treatment (16.1 +/- 5.8 versus 14.1 +/- 5.4 months), AST increase > or = 1.25 of normal (29.6 versus 25.9%), or ALT increase > or = 1.25 of normal (33.3 versus 22.4%). In co-infected patients, ALT increase (> or = 1.25 of normal), but not AST increase, at the time of indinavir initiation was statistically related to the occurrence of nephrolithiasis. CONCLUSIONS: We found a significant increase of nephrolithiasis incidence in patients co-infected with HIV-1 and HCV or HBV, which suggests that underlying multifactorial hepatic damage may limit liver catabolism of indinavir, and consequently increase its renal excretion and the risk of nephrolithiasis. Caution is therefore advised when initiating indinavir treatment in HIV patients with evidence of HBV or HCV infection.

Adult↗

PubMed2000

Analysis of hypophosphatemia in calcium nephrolithiasis.

PURPOSE AND METHODS: To analyze the pathophysiology of hypophosphatemia in calcium nephrolithiasis, we investigated the relation between serum phosphorus, 1,25-dihydroxyvitamin D, and parathyroid hormone (PTH) levels in 63 consecutive patients with calcium nephrolithiasis, comparing them with 26 age-matched control subjects. RESULTS: Serum phosphorus concentrations in normocalciuric and absorptive hypercalciuric stone formers were significantly decreased compared with control subjects (P<0.001 and P<0.01, respectively). The fractional excretion (TRP) and renal threshold (TmP/GFR) of phosphorus were significantly decreased in the subjects with nephrolithiasis (P<0.01 and P<0.001, respectively). Serum phosphorus concentrations were inversely correlated with serum 1, 25-dihydroxyvitamin D in control subjects and in absorptive hypercalciuric stone formers (P<0.01 and P <0.05, respectively), suggesting that the physiologic relation between phosphorus and 1, 25-dihydroxyvitamin D is maintained in these patients. Serum phosphorus concentrations in absorptive hypercalciuric patients, although related to 1,25-dihydroxyvitamin D, were not related to PTH even though PTH and 1,25-dihydroxyvitamin D concentrations were directly related (P<0.05). The lack of a relation between PTH and serum phosphorus concentrations in absorptive hypercalciuric stone formers was similar to that in controls. In normocalciuric stone formers, there was no relation between serum 1,25-dihydroxyvitamin D and serum phosphorus, but PTH and 1,25-dihydroxyvitamin D were inversely correlated (P<0.05). CONCLUSIONS: Abnormal renal tubular function with a depressed rate of renal phosphorus transport and an abnormal 1,25-dihydroxyvitamin D concentration is common in nephrolithiasis. Differences in the relations between phosphorus and 1,25-dihydroxyvitamin D observed in hypercalciuric v normocalciuric subjects suggest that the pathogenesis of proximal tubulopathy differs among patients with nephrolithiasis.

Adult↗

PubMedDate not supplied

[Nephrolithiasis and topiramate].

INTRODUCTION: Topiramate (TPM) is a new antiepileptic drug whose multiple mechanisms of action justify both its broad therapeutic spectrum and its increasingly widespread use in childhood epilepsy. TPM acts as a carbonic anhydrase inhibitor and, although this does not affect its effectiveness as an antiepileptic, it does account for certain side effects such as nephrolithiasis. The frequency of nephrolithiasis secondary to TPM in childhood is unknown and we have only found reports of five cases in children. CASE REPORTS: We describe two cases of medication-resistant infantile epilepsy--a 3-year-old female with Dravet's syndrome and a male aged 4.5 years with Lennox-Gastaut syndrome. In both cases the decision was made to introduce TPM as add-on therapy after a prolonged therapeutic programme; a high degree of effectiveness was achieved in both patients. Nevertheless, the two patients developed nephrolithiasis secondary to TPM, which in the second case was related to the simultaneous treatment with adrenocorticotropic hormone (ACTH), while no known favouring factor was found in the first patient. CONCLUSIONS: We outline the physiopathogenic mechanism explaining nephrolithiasis secondary to TPM, the risk factors involved and the therapeutic and preventive options available in dealing with this side effect, which occurs in a low percentage of cases but which usually means stopping administration of this therapy. We therefore believe it necessary to analyse the risk factors for nephrolithiasis before prescribing the drug and we suggest that generalised preventive measures should be implemented, especially in children who are carriers of encephalopathies or conditions that reduce mobility.

Anticonvulsants↗

PubMed1988

[Urinary magnesium excretion in nephrolithiasis].

Magnesium urine excretion and its correlation with calcium urine excretion were studied in 152 patients with nephrolithiasis by atomic-absorption spectrophotometry. In 14.5% of the patients with unilateral nephrolithiasis and in the 25.6% of the patients with bilateral nephrolithiasis the magnesium urine excretion was lowered. Following calcium loading the magnesiumuria in healthy persons was reliably and positively influenced while in the patients with nephrolithiasis with initial lowered magnesium excretion there was an insignificant increase. The ration MgU/CaU is of special importance for the evaluation of the lithogenic risk. The determination of the Ca-Mg interrelation is obligatory for every patient with nephrolithiasis because of its great practical importance for the treatment of these patients.

Adolescent↗

PubMed1993

[Estimation of selected markers of bone metabolism inpatients with nephrolithiasis].

UNLABELLED: 19 patients with active nephrolithiasis, 14 patients with non-active nephrolithiasis and 17 healthy subjects were examined. After 7 days consumption of standardized low calcium, low phosphate, low purine and low protein diet, plasma parathyroid hormone (PTH) and osteocalcin concentration, activity of the alkaline phosphatase and its bone fraction were assessed before and after 4 hours i.v. infusion of calcium gluconate (15 mg/kg b.w. in 500 ml 0.9% NaCl). In addition, urinary excretion of oxalate, calcium, phosphate and magnesium were estimated in all examined groups. CONCLUSIONS: 1. In comparison to healthy subjects, patients with nephrolithiasis are characterized by higher plasma PTH and osteocalcin concentration, increased activity of bone fraction of alkaline phosphatase and urinary oxalate and calcium excretion. 2. Disturbances of calcium-phosphate and oxalate metabolism, PTH secretion and bone osteoblastic activity found in patients with active nephrolithiasis are qualitatively similar but quantitatively more intensive than in patients with non-active nephrolithiasis.

Adult↗

PubMed1997

Markers of bone turnover in patients with nephrolithiasis.

A total of 19 patients with active nephrolithiasis, 14 patients with non-active nephrolithiasis and 17 healthy subjects were examined under standardized intake of calcium, phosphorus, purine and protein. In patients with both active and non-active renal stone disease the following abnormalities were found: elevated plasma levels of PTH and osteocalcin, increased activity of the bone isozyme of alkaline phosphatase, low plasma levels of phosphate and increased urinary excretion of calcium and oxalic acid. These abnormalities were more marked in patients with active than non-active nephrolithiasis. No correlation was found between plasma PTH levels and parameters of bone turnover as well as calciuria and oxaluria. Results presented in this paper suggest that (a) Smith's criteria of active renal stone disease are of minor pathogenetic and therapeutic value and (b) patients with active nephrolithiasis differ from non-active renal stone formers by more elevated oxaluria and markers of bone turnover and more marked abnormalities in calcium-phosphate metabolism related parameters.

Adult↗

PubMed2004

Absence or decreased endogenous thiosulfaturia: a cause of recurrent calcium nephrolithiasis.

In two earlier publications we reported excellent therapeutic results in patients with recurrent calcium nephrolithiasis, using oral or intravenous i.v. sodium thiosulfate on the one hand, and on treatment of tumorus-soft periarticular tissues calcifications on the other. Thus, we considered useful to measure endogenous thiosulfaturia, using a specific HPLC method, in 25 healthy adult males and 25 patients with recurrent calcium nephrolithiasis. Healthy adult males excreted between 11 and 16 microM/24 hour of endogenous thiosulfate, while patients with recurrent calcium nephrolithiasis excreted significantly lower amounts of 6 and 10 microM/24 hour, except one patient, who did not excrete endogenous thiosulfate, reflecting probably a genetic abnormality. Thiosulfate is a unique agent for treatment of recurrent calcium nephrolithiasis as well as some other abnormal calcium depositions. Two doses of 5 mM sodium thiosulfate daily are therapeutically sufficient.

Adult↗

PubMed2002

Risk factors for nephrolithiasis in patients with familial idiopathic hypercalciuria.

PURPOSE: About 40% of patients with nephrolithiasis have idiopathic hypercalciuria, sometimes associated with a family history of kidney stones. In these families, little is known about the frequency of, and risk factors for, stone formation among hypercalciuric patients. We therefore conducted a prospective study of 216 subjects from 33 families with idiopathic hypercalciuria. MATERIALS AND METHODS: We recorded the age, weight, and history of calcium stones in all subjects, and measured 24-hour urine volume and excretion of calcium, uric acid, sodium, magnesium, urea, citrate, phosphate, and sulfate on a nonrestricted diet. We performed a more complete metabolic evaluation in many of the hypercalciuric subjects (calciuria/weight >0.1 mmol/kg/d). Multivariate logistic regression analysis was performed to identify independent risk factors for stone formation. RESULTS: The prevalence of self-reported nephrolithiasis was 46% (61/132) in hypercalciuric subjects and 11% (7/63) in normocalciuric subjects (P <0.0001). In multivariate analysis, age (odds ratio [OR] per 10 years of age = 1.3; 95% confidence interval [CI]: 1.1 to 1.6), urine calcium excretion (OR = 1.3 per mmol/d increase; 95% CI: 1.2 to 1.5), and uric acid excretion (OR = 3.3 per mmol/d increase; 95% CI: 1.4 to 7.5) were independent risk factors for nephrolithiasis. The risk of nephrolithiasis increased progressively with greater levels of hypercalciuria. CONCLUSION: We found a significant dose-effect association between calciuria and stone disease in patients with familial hypercalciuria. Other factors associated with stone formation included higher uric acid excretion, probably reflecting higher food intake, and age, probably reflecting the length of exposure to hypercalciuria and hyperuricosuria.

Adult↗

PubMed1998

X-linked recessive nephrolithiasis: presentation and diagnosis in children.

We report a new X-linked recessive nephrolithiasis kindred. X-linked recessive nephrolithiasis is a recently described disease characterized by recurrent nephrolithiasis, nephrocalcinosis, and progressive renal failure, associated with mutations in a renal chloride channel gene, chloride channel number 5. Screening individuals at risk with renal ultrasonography and measurement of urinary excretion of low molecular weight proteins and calcium will exclude boys without X-linked recessive nephrolithiasis kindred and identify boys likely to have the disease.

Calcium↗

PubMed1993

Magnesium oxide administration and prevention of calcium oxalate nephrolithiasis.

We studied the effect of oral administration of magnesium oxide (MgO) on calcium oxalate (CaOx) nephrolithiasis in rats. Nephrolithiasis was induced by administration of 1.0% ethylene glycol (EG) in drinking water. Magnesium oxide was given mixed with food at 500 mg./100 g. rat chow. Dispensation of MgO resulted in a significant increase of urinary pH and a modest increase in urinary excretion of citrate. Urinary excretion of oxalate started to decline by day 14 and was significantly reduced on days 21 and 28. All rats receiving EG displayed crystalluria. From the group receiving EG only, 3 of 4 rats sacrificed on day 15 and 2 of 4 rats sacrificed on day 29 had CaOx crystal deposits in their kidneys. None of the 8 rats who received both EG and MgO had CaOx nephrolithiasis. Thus our findings indicate that dispensation of magnesium as MgO can be beneficial against calcium oxalate nephrolithiasis.

Animals↗

PubMed1985

Long-term treatment of calcium nephrolithiasis with potassium citrate.

The long-term effects of potassium citrate therapy (usually 20 mEq. 3 times daily during 1 to 4.33 years) were examined in 89 patients with hypocitraturic calcium nephrolithiasis or uric acid lithiasis, with or without calcium nephrolithiasis. Hypocitraturia caused by renal tubular acidosis or chronic diarrheal syndrome was associated with other metabolic abnormalities, such as hypercalciuria or hyperuricosuria, or occurred alone. Potassium citrate therapy caused a sustained increase in urinary pH and potassium, and restored urinary citrate to normal levels. No substantial or significant changes occurred in urinary uric acid, oxalate, sodium or phosphorus levels, or total volume. Owing to these physiological changes, uric acid solubility increased, urinary saturation of calcium oxalate decreased and the propensity for spontaneous nucleation of calcium oxalate was reduced to normal. Therefore, the physicochemical environment of urine following treatment became less conducive to the crystallization of calcium oxalate or uric acid, since it stimulated that of normal subjects without stones. Commensurate with the aforementioned physiological and physicochemical changes the treatment produced clinical improvement, since individual stone formation decreased in 97.8 per cent of the patients, remission was obtained in 79.8 per cent and the need for surgical treatment of newly formed stones was eliminated. In patients with relapse after other treatment, such as thiazide, the addition of potassium citrate induced clinical improvement. Thus, our study provides physiological, physicochemical and clinical validation for the use of potassium citrate in the treatment of hypocitraturic calcium nephrolithiasis and uric acid lithiasis with or without calcium nephrolithiasis.

Adult↗

PubMedDate not supplied

Nephrolithiasis with unusual initial symptoms.

OBJECTIVE: To describe a less common initial symptom of nephrolithiasis, its diagnostic pitfalls, risk factors, and mimicry of other conditions. Intervention and long-term management of nephrolithiasis is also discussed. CLINICAL FEATURES: A Caucasian man aged 25 years had sudden bilateral inguinal and occasional periumbilical pain. The initial symptom suggested an abdominal pathologic condition; however, costovertebral angle pain followed 1 hour later with no radiation between the 2 anatomic sites. The initial urine dipstick result was negative for hematuria, but a kidney, ureter, and bladder radiograph revealed a smooth 2-mm x 3-mm stone lodged at the left: vesico-ureteral junction. INTERVENTION AND OUTCOME: The patient was referred to a regional university medical center to receive extracorporeal shockwave lithotripsy several days after his initial visit. He was given pain medicine for the waiting period and received daily lumbar spine adjustments with a mild reduction in pain. He eventually received ureteroscopic laser lithotripsy because the shock-wave unit had malfunctioned before his appointment. The fragment analysis showed a calcium oxalate composition, and the patient was advised to lower his intake of oxalates. The patient had become a vegetarian approximately 3 months before this first stone episode. CONCLUSION: Nephrolithiasis is a condition commonly seen in chiropractic practice. Although it is usually easy to recognize, the diagnosis can be elusive if the typical historic factors and diagnostic results are absent or altered. The short-term management of nephrolithiasis is pain management, stone elimination, and the collection of a specimen to identify the composition and underlying metabolic abnormality. Long-term management is to prevent the recurrence of stones. Conservative comanagement by the chiropractic physician can be implemented through nutritional means.

Abdominal Pain↗

PubMed2006

Modeling of hyperoxaluric calcium oxalate nephrolithiasis: experimental induction of hyperoxaluria by hydroxy-L-proline.

A number of animal models have been developed to investigate calcium oxalate (CaOx) nephrolithiasis. Ethylene glycol (EG)-induced hyperoxaluria in rats is most common, but is criticized because EG and some of its metabolites are nephrotoxic and EG causes metabolic acidosis. Both oxalate (Ox) and CaOx crystals are also injurious to renal epithelial cells. Thus, it is difficult to distinguish the effects of EG and its metabolites from those induced by Ox and CaOx crystals. This study was performed to investigate hydroxy-L-proline (HLP), a common ingredient of many diets, as a hyperoxaluria-inducing agent. In rats, HLP has been shown to induce CaOx nephrolithiasis in only hypercalciuric conditions. Five percent HLP mixed with chow was given to male Sprague-Dawley rats for 63 days, resulting in hyperoxaluria, CaOx crystalluria, and nephrolithiasis. Crystal deposits were surrounded by ED-1-positive inflammatory cells. Cell injury and death was followed by regeneration, as suggested by an increase in proliferating cell nuclear antigen-positive cells. Both osteopontin (OPN) and CD44 were upregulated. Staining for CD44 and OPN was intense in cells lining the tubules that contained crystals. Along with a rise in urinary Ox and lactate dehydrogenase, there were significant increases in 8-isoprostane and hydrogen peroxide excretion, indicating that the oxidative stress induced cell injury. Thus, HLP-induced hyperoxaluria alone can induce CaOx nephrolithiasis in rats.

Animals↗

PubMed2000

Pathogenesis of Dent's disease and related syndromes of X-linked nephrolithiasis.

Renal stone disease, which affects 12% of males and 5% of females by the seventh decade, occurs as an inherited disorder in 45% of patients and is most commonly associated with hypercalciuria. The biochemical basis for hereditary nephrolithiasis and hypercalciuria is unknown, and this has therefore been investigated by a "positional cloning" approach. As a first step in this approach, the chromosomal locations of two disorders referred to as Dent's disease and X-linked recessive nephrolithiasis (XRN) were determined. These two disorders, which represent unusual forms of the renal Fanconi syndrome, are characterized by a low molecular weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis and renal failure. An X-linked inheritance for XRN was established by studies of a North American kindred, and a similar inheritance for Dent's disease was indicated by the observation of a greater disease severity in males and an absence of male-to-male transmission in five British families. X-linked polymorphic genetic markers were used in linkage studies of these families, and the genes causing Dent's disease and XRN were mapped to Xp11. In addition, in one family with Dent's disease, a microdeletion involving the DNA probe M27 beta was identified. This microdeletion was further characterized by using yeast artificial chromosomes (YACs) and its size was estimated to be 515 Kb. A search for renal-expressed genes from this region identified a novel gene encoding a chloride channel (CLCN5) with similarities to a family of voltage-gated chloride channels. Molecular genetic studies of CLCN5 demonstrated that mutations, which resulted in a functional loss, were associated with Dent's disease and XRN. In addition, such CLCN5 mutations that would result in a functional loss have also been demonstrated in Japanese children with idiopathic low molecular weight proteinuria, hypercalciuria and nephrocalcinosis, and an Italian kindred with X-linked recessive hypophosphatemic rickets (XLRH) and hypercalciuria. Thus, four hereditary disorders of nephrolithiasis are due to mutations of the novel chloride channel, CLCN5.

Amino Acid Sequence↗

PubMed2001

Biochemical profile of idiopathic uric acid nephrolithiasis.

BACKGROUND: The objective of this study was to elucidate a biochemical profile of patients with idiopathic uric acid nephrolithiasis, without secondary causes (such as dehydration or diarrhea). Study subjects comprised 56 patients with idiopathic uric acid nephrolithiasis (UA stone group) who underwent a full outpatient evaluation. The control group was composed of 54 with absorptive hypercalciuria and 2 normal subjects, matched with the UA stone group according to age, body mass index, and gender. METHODS: Urinary pH and ammonium and serum and urinary uric acid were measured. The fractional excretion of urate was calculated. RESULTS: Compared with the control group, the UA stone group had a significantly higher serum uric acid and significantly lower urinary uric acid, pH (5.34 +/- 0.23 vs. 6.17 +/- 0.36, P < 0.001), and fractional excretion of urate (0.052 +/- 0.028 vs. 0.080 +/- 0.029, P < 0.001), but individual values overlapped considerably between the two groups. Discriminant analysis of the relationship between urinary pH and fractional excretion of urate yielded a "discriminant score," which provided a much better separation between the two groups, with a correct classification in 95.5% of subjects. In contrast, urinary ammonium, citrate, sulfate, and potassium did not differ between two groups. CONCLUSIONS: In idiopathic uric acid nephrolithiasis, urinary pH and fractional excretion of urate are significantly lower than in control subjects, suggestive of defects in urinary acidification and urate excretion. Since these impairments are believed to be associated with primary gout, the underlying disturbance in idiopathic uric acid nephrolithiasis may be primary gout.

Adult↗

PubMed2004

Ephedrine- and guaifenesin-induced nephrolithiasis.

OBJECTIVES: Ephedrine and guaifenesin are herbal supplements that have experienced increased use over the past decade. Ephedrine has been used as a stimulant and weight-loss product, guaifenesin as an expectorant and cough suppressant; both are found in combination in many antitussives and expectorants. This paper reviews the reported cases of ephedrine- and guaifenesin-induced nephrolithiasis, as well as the diagnostic techniques and treatments that have been successfully used for these stones. DESIGN: A systematic review of the literature pertaining to nephrolithiasis and the compounds ephedrine and guaifenesin was conducted. RESULTS: Ephedrine and guaifenesin use results in over 35% of urinary stones that are related to pharmaceutical metabolites, and collectively are present in 0.1% of all urinary stones. These calculi are radiolucent, requiring the use of computerized tomography (CT scan) for diagnosis. Alkalinization therapy offers an alternative to surgical intervention and may have a role in prevention of recurrence. CONCLUSIONS: Ephedrine and guaifenesin have been shown to cause nephrolithiasis in cases of abuse when taken individually or in combination. It is important for the clinician to be aware of the potential for these compounds to cause nephrolithiasis.

Antitussive Agents↗

PubMed2004

The relationship of 3' vitamin D receptor haplotypes to urinary supersaturation of calcium oxalate salts and to age at onset and familial prevalence of nephrolithiasis.

BACKGROUND: Idiopathic hypercalciuria (IHc) and idiopathic hypocitraturia are frequently associated with calcium nephrolithiasis. We investigated the relationship of vitamin D receptor (VDR) polymorphisms (BsmI, TaqI and FokI) to urinary supersaturation of calcium oxalate salts in recurrent calcium oxalate stone formers with IHc and the clinical relevance of this relationship. METHODS: The study included 110 Caucasian stone formers with IHc and 127 unrelated healthy controls without history of nephrolithiasis. Age at onset of nephrolithiasis, familial history score (FHS) and the ion activity product of calcium oxalate salts in urine (AP(CaOx)) were tabulated. BsmI, TaqI and FokI VDR polymorphisms were evaluated in all participants. RESULTS: Patients and controls were classified as homozygous (bbTT and BBtt) or heterozygous in relation to BsmI and TaqI polymorphisms. Compared with BBtt patients, bbTT homozygous stone formers showed lower citrate excretion (1.91+/-0.89 vs 3.46+/-1.39 mmol/24 h, P = 0.004) and higher AP(CaOx) (2.02+/-0.51 vs 1.53+/-0.53, P = 0.006). Among controls, there were similar differences in citrate excretion and AP(CaOx) between the two groups, but they were not statistically significant. Compared with BBtt, bbTT patients showed lower mean age at onset of nephrolithiasis (29.7+/-12.1 vs 38.1+/-12.7 years, P = 0.008) and higher values of FHS (2.45+/-1.9 vs 0.83+/-0.7, P = 0.006). Similar results were obtained for individual BsmI and TaqI alleles. The analysis of FokI alleles was not informative. CONCLUSIONS: Recurrent calcium oxalate stone formers with IHc and the bT VDR haplotype have more aggressive kidney stone diseases as indicated by a higher familial incidence and lower mean age at onset. This clinical severity is associated with the higher urinary supersaturation of calcium oxalate salts and abnormalities of renal citrate handling.

Adult↗