Anwendung des Lasers für die Harnsteinanalyse

Medullary sponge kidney (MSK) is an anomaly of the kidney with cystic enlargement of distal tubules generating stasis zones where calcium salt deposits may form and grow locally. From an epidemiological point of view, MSK is reported in 2% to more than 20% of calcium stone formers. The association of stasis and various metabolic disorders explains a high recurrence rate of stones in affected patients. The composition of stones has been poorly investigated. The aim of this study is to compare stone composition and morphology in MSK and non-MSK patients.Material and methods: 1036 stones from MSK patients and 31,494 stones from non-MSK patients were submitted to a morpho-constitutional analysis based on morphological typing under stereo microscope and precise characterization of chemical and crystalline phases by Fourier transform infrared spectroscopy. Results and discussion:Regarding patients, the male to female ratio was significantly lower in MSK vs non-MSK subjects (1.48 vs 2.09, p < 0.00001). The recurrence rate was significantly higher in MSK patients (85.0% vs 39.5% in non-MSK, p < 0.000001). Stones were more often spontaneously passed in MSK vs non-MSK subjects (45.7% vs 34.6%, p < 0.000001). Stones were mainly composed of calcium oxalate in both groups (66.3% vs 72.5%). However, the slight decrease in the occurrence of calcium oxalate stones was mainly supported by weddellite calculi, less frequent in MSK (17.0% vs 21.6% in non-MSK, p < 0.001). The main point was the high proportion of stones mainly composed of calcium phosphates: 28.9% in MSK vs 13.9% in non-MSK patients) with a high proportion of stones exhibiting a IVa2 morphology which is a marker for distal tubular acidification defect (12.1% in MSK vs 0.4% in non-MSK patients, p < 0.000001). Finally, while stones nucleated from a papillary Randall's plaque were found with a similar frequency in both groups, calcium phosphate nucleus was significantly more frequent in MSK than in non-MSK stones (68.8% vs 48.9%, p < 0.000001), suggesting a frequent initiation of stones from calcium phosphate plugs in distal tubules ectasias.

Section: Discussionsupporting

confidence: 89%

Medullary sponge kidney: what kind of stones?

Daudon¹,

Frochot²,

Bazin³

et al. 2022

“…In Europe, and particularly in France, this drug has been identified with the same frequency as in the United States [28], which means that triamterene was the main cause of drug-induced stones in the world for nearly a decade, with also several reported cases of triamterene-induced crystal nephropathies [29,30].…”

Section: Triamterenementioning

confidence: 97%

“…Furthermore, the hepatic metabolism of triamterene led to the predominant formation of 4hydroxytriamterene sulfate with high urinary excretion (Figure 1). This metabolite was often abundant, sometimes predominant, and even almost pure in some stones [28,32].…”

Section: Triamterenementioning

confidence: 99%

Drug-induced nephrolithiasis and crystalluria: the particular case of the sulfasalazine derivatives

Chebion¹,

Bugni²,

Gérin³

et al. 2022

Introduction: Drug-induced calculi are rarely reported in literature but represent a seldom reported complication of long-term or high-dose prescription of certain medications. We review here some drugs involved in stone formation from first case reports of sulfonamides in the 1930s to protease inhibitors and sulfadiazine with more recent emergence of HIV and opportunistic infections. Finally, we will study in particular sulfasalazine and mesalazine, two different forms of a drug used for treatment of ulcerative colitis or Crohn's disease.Material and methods: Review of the literature and report of a series of ten new cases of mesalazineinduced nephrolithiasis.Results and discussion: Ten patients (eight women and two men) produced stones spontaneously passed (n = 9) or surgically removed (n = 1). Patients received mesalazine either for ulcerative colitis (n = 6) or Crohn's disease (n = 4). The daily oral dose was 4 g/d in nine patients and only 2 g/d in one subject. The duration of medication before stone episode ranged from one month up to 15 years with an average of four years. Stone analysis found pure mesalazine in all stones analyzed (n = 9). Rod-shaped crystals found in urine of one patient (stone unavailable) were identified as mesalazine by Fourier transform infrared spectroscopy.

“…That vibration does not belong to whewellite and results from the ν 3 vibration of the PO 4 group present in organic material such as uropontin which is known to have a strong affinity for several crystalline faces (100/121) of COM [35]. It has been shown that this organic phosphate may be converted into apatite after pyrolysis of COM stones [36].…”

Section: Infrared Analysismentioning

confidence: 99%

The type Ic morphology of urinary calculi: an alert to primary hyperoxaluria? Experience with 43 Moroccan children

Meiouet¹,

Kabbaj²,

Daudon³

2022

Primary hyperoxaluria is the most severe stone disease responsible for multiple stone recurrence and impairment of kidney function. It is a rare inherited disease with an autosomal transmission. Due to the high proportion of consanguineous marriages by comparison to other areas in the world, this pathology is more frequent in North Africa. Stones are made of calcium oxalate monohydrate, which is not unique to the disease and cannot help physicians for the diagnosis. By contrast, stone morphology may be a useful marker of the pathology. We report our experience based on 614 stones from Moroccan children analyzed by infrared spectroscopy and examined by stereomicroscopy for the determination of their morphological type. Our results show that 85 stones (13.8%) exhibit a type Ic morphology, strongly suggestive of the disease in children patients. It was confirmed in all subjects of a subgroup of 43 patients who benefited from urinary biochemical explorations revealing whewellite crystalluria and a very high oxalate to creatinine ratio.