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Molti lavori recenti analizzano l'associazione fra calcolosi renale e altre patologie non trasmissibili tipiche dei paesi industrializzati. I dati epidemiologici, su casistiche ampie, indicano un aumento di incidenza della calcolosi in pazienti con sindrome metabolica, obesità e ipertensione. Viene anche descritto un aumento del rischio di infarto miocardico e di ictus nei litiasici. Si ipotizza che il denominatore comune in queste patologie sia l'aumento della resistenza all'insulina. Questo causa alterazioni della biochimica urinaria, pH più acido e riduzione della citraturia, tali da aumentare il rischio litogeno. Nel ratto diabetico è stata descritta una steatosi renale che riduce l'ammoniogenesi e che è reversibile con una terapia con PPARγ. Il pioglitazone è stato efficace nel ridurre il danno renale indotto nel ratto da etilen glicole. Altra associazione nota è quella fra calcolosi renale e gotta. Due recenti studi documentano un'incidenza della calcolosi calcica e non solo urica nella gotta, con anomalie metaboliche in parte simili a quelle dei pazienti non gottosi. L'indagine TC mostra che l'incidenza di calcolosi è sottostimata nella gotta e, inoltre, la calcolosi, in alcuni pazienti, precede anche di molti anni l'attacco gottoso. Un altro argomento analizza il potenziale effetto che favorisce la calcolosi nelle donne trattate con calcio e vitamina D. Emergono un modesto ma significativo aumento del rischio litogeno indipendente da altre covariabili e un conseguente invito all'attenta valutazione del rapporto rischio/beneficio. La chirurgia bariatrica per la correzione della grave obesità era, in passato, gravata da un elevato rischio di calcolosi renale iperossalurica con quadri anche di ossalosi severa. Negli ultimi anni si sono diffuse tecniche meno litogene come il bendaggio gastrico e il bypass gastrico alla Roux. Iperossaluria e ipocitraturia conseguono a questi interventi e il rischio di calcolosi è di gran lunga inferiore, ma restano segnalazioni in letteratura di casi di ossalosi renale specialmente dopo bypass gastrico alla Roux.

This is the second part of an article on the metabolic diagnosis of nephrolithiasis, the first part of which was published in the previous issue of this journal. Here we report on three clinical cases representative of a rational diagnostic workup of nephrolithiasis in specific clinical contexts: secondary hyperuricemia, cystinuria, and primary hyperoxaluria. Nephrolithiasis is one of the most frequent causes of hospitalization in nephrology and urology units in our country and is an important source of discomfort in affected patients. Despite the availability of modern, minimally invasive endourological procedures to remove stones from the urinary tract, prevention of stone recurrences remains an essential strategy. Chemical analysis of stones, whether passed spontaneously or removed surgically, is a crucial step in etiological diagnostics aimed at devising adequate prevention strategies. Modern endoscopic lithotripsy techniques provide complete fragmentation of stones and, compared to extracorporeal shock wave lithotripsy, have the advantage of avoiding painful elimination of fragments through the urinary tract. This means, however, that stone fragments are often unavailable for analysis, thereby depriving the nephrologist of an important tool for diagnosis. As a consequence, metabolic evaluation tends to be the only means of establishing the etiology of stones and preventing their recurrence. We conclude that close collaboration between nephrologists and urologists is a prerequisite for optimizing the diagnosis and treatment of stone disease. [ABSTRACT FROM AUTHOR]

Metabolic diagnosis of nephrolithiasis. Clinical cases (Part I) Nephrolithiasis is one of the most frequent causes of hospitalization in nephrology and urology units in our country and is an important source of discomfort in affected patients. Despite the availability of modern, minimally invasive endourological procedures to remove stones from the urinary tract, prevention of stone recurrences remains an essential strategy. Chemical analysis of stones, whether passed spontaneously or removed surgically, is a crucial step in etiological diagnostics aimed at devising adequate prevention strategies. Modern endoscopic lithotripsy techniques provide complete fragmentation of stones and, compared to extracorporeal shock wave lithotripsy, have the advantage of avoiding painful elimination of fragments through the urinary tract. This means, however, that stone fragments are often unavailable for analysis, thereby depriving the nephrologist of an important tool for diagnosis. As a consequence, metabolic evaluation tends to be the only means of establishing the etiology of stones and preventing their recurrence. Among patients attending our kidney stone center, we selected five clinical cases representative of a rational diagnostic workup in specific clinical contexts. Two of these nephrolithiasis cases (in a patient with osteoporosis and in a patient with primary hyperparathyroidism) are reported here (Part I); the remaining three will be discussed in the next issue of this journal (Part II). [ABSTRACT FROM AUTHOR]

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) primarily affects small- and medium-sized arteries, including kidney vessels, thus causing rapidly progressive glomerulonephritis. The pathogenesis of AAV is intricate and several factors, including infections, are known to possibly trigger the autoimmune process. Numerous studies have reported that SARS-CoV-2 might cause acute kidney injury (AKI). To date, a modest number of AAV with COVID-19 cases has been reported. Herein, we discuss the case of a 61-year-old man with new-onset of diffuse proliferative ANCA-associated glomerulonephritis after COVID-19., (Copyright by Società Italiana di Nefrologia SIN, Rome,Italy.)

Introduction: In this paper we investigated whether cholecalciferol supplementation, prescribed to treat vitamin D deficiency in patients with nephrolithiasis, increased the risk of stone recurrence., Methods: Calcium excretion and urine supersaturation with calcium oxalate (βCaOx) and brushite (βbsh) were evaluated in 33 kidney stone formers (aged 56±17; 12 males), both before and after therapy with cholecalciferol, prescribed as oral bolus of 100.000-200.000 UI, followed by maintenance doses, repeated every week (5.000-10.000 UI) or month (25.000-50.000 UI). During the study, patients followed a dietary regimen which included a daily calcium intake of about 800-1000 mg., Results: Urinary nitrogen, sodium and ash-acid excretion did not significantly change during the study. After cholecalciferol supplementation, the main results were as follows: both serum calcium and phosphate did not vary significantly; 25(OH)VitD₃ increased from 11,8±5,5 to 40,2±12,2 ng/mL (p<0,01); 1,25(OH) ₂ VitD₃ increased from 41,6±17,6 to 54,0±16,0 pg/mL (p<0,01); PTH decreased from 75,0±27,2 to 56,7±21,1 pg/mL (p<0,01); daily urinary calcium increased from 2,7±1,5 to 3,6±1,6 mg/Kg b.w. (p<0,01), whereas fasting urinary calcium did not change significantly. After therapy, βbsh increased from 0,9±0,7 to 1,3±1,3 (p=0,02) and βCaOx did not vary significantly. Before cholecalciferol supplementation, 6/33 patients (18.2%) were hypercalciuric, whereas 13/33 patients (39,4%) showed hypercalciuria after supplementation (pX²=0,03)., Conclusions: Cholecalciferol supplementation for vitamin D deficiency may increase both urinary calcium and urine supersaturation in stone formers. If vitamin D supplements are needed in these patients, a careful monitoring of urine metabolic profile is warranted, in order to customize the metaphylaxis accordingly (hydration, potassium citrate, thiazides)., (Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.)

Primary hyperparathyroidism (PHPT) may favor nephrolithiasis mainly through an increase in calcium and phosphate urinary excretion. Cinacalcet exhibits good efficacy to control hypercalcemia in PHPT, but it is not so far known whether it might be a useful tool to prevent stone recurrences. Of 67 patients with PHPT and recurrent nephrolithiasis, 55 underwent parathyroidectomy (PTX) and 12, not eligible to PTX, were prescribed Cinacalcet. All the patients were evaluated for mineral metabolism, including estimation of state of saturation for calcium oxalate (CaOx) and brushite (bsh), both at baseline and after either PTX or Cinacalcet. PTX compared to baseline reduced PTH (4617 vs 15786 pg/mL, p<0.01), calcemia (9.40.5 vs 11.30.9 mg/dL, p<0.01), calciuria (3.62.3 vs 9.24.5 mmol/24h, p<0.01), phosphaturia (18.47.1 vs 21.99.9 mmol/24h, p<0.05), CaOx (4.73.9 vs 9.86.8, p<0.01) and bsh (1.10.9 vs 3.22.2, p<0.01). Cinacalcet decreased both PTH (13379 vs 17187 pg/mL, p<0.05) and calcemia (9.70.6 vs 11.20.8 mg/dL, p<0.001), whereas no change was seen in calciuria (7.42.2 vs 7.42.4 mmol/24h, p=ns), phosphaturia (21.97.3 vs 23.06.5 mmol/24h, p=ns), CaOx (6.92.7 vs 5.42.5, p=ns) and bsh (1.71.1 vs 1.31.3, p=ns). We conclude that in patients with PHPT, PTX is able to decrease the risk for crystallization of calcium salts, whereas calcimimetic Cinacalcet did not. Therefore, in patients with PHPT complicated with nephrolithiasis only PTX can improve urine biochemistries thereby reducing the risk for recurrent calcium stone disease.

Background: In this paper, the clinical and metabolic patterns of nephrolithiasis in different ages of adulthood are studied., Methods: Eight-hundred patients observed at the Mauriziano Hospital between 1990 and 1995, were classified into 3 groups, on the basis of age at the onset of disease: A: 20 through 39 years; B: 40 through 59; C: 60 years and over., Results: Calcium-oxalate stones had a lower recurrence in C (19.1%) and B (31.5%) than in A (41.7%). Pure uric acid stones recurred in 18.9% of C, 16.7% of B and 4.3% of A. The prevalence of hypercalciuria was higher in A (50.3%) than in B (35.9%) and C (36%); so did hypocitraturia. Hyperuricuria was lower in A (5%, p < 0.05) than in B (9.4%) and C (10%). Low urine pH (< 5.5) was 13% in A, 21.3% in B, 38% in C. Prevalence of hyperoxaluria was about 14% in all groups. The whole prevalence of secondary forms of stone disease was 13% in A, 12% in B and 30% in C. Differences among groups were mainly due to prevalence of urological abnormalities and urinary tract infection. In patients without metabolic disturbances. urological abnormalities or urinary tract infections altogether, were 4.6% in A; 5.2% in B; 33% in C. Urological approach removed 8% of stones in A, 5.6% in B and 10.2% in C., Conclusions: Higher morbidity in younger patients could be due to a lower prevalence of easier-passing uric acid stones. The higher occurrence of urological disturbances and struvite stones in the elderly could explain the higher morbidity in this group.

The increased survival of patients in dialysis and the gradual increase in the age of uremic patients commencing chronic dialysis raises serious problems for the creation and maintenance of efficient vascular access. In cases in which it is extremely difficult to create arteriovenous fistulas (AVF) using existing upper limb veins, it is possible to resort to vascular grafts, lower limb AVF, central venous catheters or refer the patients for peritoneal dialysis if this method is technically possible. In order to evaluate the incidence of these phenomena in quantitative terms, the authors have made a retrospective analysis of patients undergoing vascular access surgery since the opening of the Dialysis Centre on 1/9/1973 to 30/9/1996. During this period (277 months) a total of 1,037 AVF implant operations were performed (in addition to 65 arteriovenous shunts in the earlier period and 28 permanent central venous catheters in the last 10 years). The survival of AVF grafts was lower than that in natural vessels in 384 patients without clinical risk. In diabetic subjects, those suffering from vascular pathologies, systemic diseases, or aged over 70, the survival of AVF was distinctly lower compared to the group without these risk factors. However, the higher risk group did not show any marked difference in survival between AVF in the patient's own veins and grafts. In only 4 out of 1,037 operations it was impossible to obtain vascular access in the upper limbs (2 patients were referred for peritoneal dialysis and AVF were executed in the thigh in 2 patients). In conclusion, the retrospective analysis of this series leads the authors to affirm that the rational use of natural vascular accesses normally allows a sufficient operating margin; however, in special cases suitable techniques (such as permanent central venous catheter or AVF in the thigh) can enable difficult situations to be resolved as an alternative to peritoneal dialysis.

Wegener's granulomatosis (WG) is a rare small vessels necrotizing and granulomatous systemic vasculitis which usually affects the respiratory-tract and the kidneys. Diagnosis is often difficult, but has become easier with antineutrophil cytoplasmic antibodies (ANCA) detection that may justify a more aggressive biopsy policy also in the elderly. Classic treatment with steroids and oral cyclophosphamide (CY) has proven to be of benefit, but side-effects are severe and frequent and the search for less toxic therapeutic schemes should be encouraged. We treated with intravenous pulses of CY (1 g/m2 monthly for 6 months, every two months for the following 6 and quarterly for another year) 5 of 7 patients with WG recently admitted to our institution. We obtained a quick, complete response in 4 of these patients, with no side effects, nor relapses, after a mean follow-up of 17 months. The only patient who did not respond was identified soon after the beginning of the treatment because of a poor reduction of ESR and could be shifted to oral administration of CY successfully. From our still limited experience CY intravenous pulses have proven to be safe and effective enough to advice its use as the first-choice treatment for WG.

Six patients (3 children and 3 adults) with the clinical and biochemical features of Bartter's syndrome are presented. Pediatric cases included a more severe form, in one patient, with physical and mental retardation, hypercalciuria and nephrocalcinosis, and a less severe one, including two patients, with milder clinical features, low calcium and high magnesium excretion and hypomagnesiemia. Adult patients were affected by either the mild congenital form (case n. 4) or the acquired variety (cases n.5 and 6). Tubular function was investigated in the 3 adults by assessing clearance measurements during maximal diuresis. There was a defective fractional distal solute reabsorption (FDR) ranging between 0.52 and 0.60. This was well below the results obtained in one patient with psychogenous vomiting (FDR 0.94) and comparable to those in two patients with interstitial nephropathies caused by vesico-ureteral reflux (FDR 0.63 and 0.67 respectively). We concluded that: 1) the etiopathogenetic spectrum of Bartter's syndrome corresponds to different clinical presentation (mild, heavy, congenital or acquired varieties), and alterations in mineral and electrolyte renal handling; 2) reduction in FDR is a feature neither essential nor exclusive of this syndrome.

The relationship between cancer and coagulation disorders is widely accepted. Such disorders can contribute to the metastatic spreading of the primary tumor. Aim of our study was to evaluate the alterations of thrombin-antithrombin III complex (TAT) measured by an ELISA plasma assay in a population of 78 patients suffering from various gastrointestinal tumors. We found high levels of TAT in 68.6% of the patients. Our data show that assay of TAT plasma levels may be a useful test in detecting early coagulation disorders in cancer patients.

Keeping calcium (Ca) balance in equilibrium is one of the main goals in dialysis patients, and the dialysis schedule by itself can affect mineral metabolism. The aim of this paper is to evaluate Ca and magnesium (Mg) balances on different Quf in patients on RDT. Twenty-one patients [7 on hemodialysis (HD), 14 on hemodiafiltration (HDF)] were studied. Ca and Mg balances were assessed by measuring Ca and Mg in whole dialysis fluid. One patients on HDF was observed for three dialysis sessions, on different Quf, and negative values were observed for Quf above 70 ml/min. Mg balance was always negative. We conclude that an accurate survey of Ca balance is mandatory in high-efficiency dialysis, when high fluxes may produce adverse effects on mineral metabolism.

Hemodialysis treatments with large surface area dialyzers were introduced in our dialysis unit since 1974. 129 uremic subjects were treated between September 1974 and August 1988. Age at start of high efficiency therapy ranged between 16 and 72 years; patients survival was: 95.3% at 1 year, 78.3% at 5 years, 65.8% at 10 years. At present 48 subjects are treated with this schedule. The key technical elements for implementation of such program include: high blood flow rates (greater than 300 ml/min), high surface area dialyzers (greater than 1.8 m2), bicarbonate as the buffer source. Traditionally, the rate of ultrafiltration was controlled by monitoring the TMP and the patients body weight, but in some case a preferred approach is the use of an automatic ultrafiltration control system. We conclude that, in a quite large dialysis population, an individualized short dialysis schedule may be safely applied for long time periods.

C-reactive protein and rheumatoid factor assays are relevant laboratory parameters, among the most used in the clinical practice, being very useful in diagnosing and "monitoring" rheumatic diseases. A quantitative test to detect these two serum proteins is an important, more specific, new tool for clinical medicine. In our study we evaluated two new laser nephelometric assays, both quantitative, based on the agglutination of polystyrene latex particles, able to show serum concentration of CRP and RF. With a similar technique we tested the presence of circulating immune complexes. We performed our tests in a group of patients with rheumatoid arthritis, other autoimmune diseases, and healthy blood bank donors assaying simultaneously, whenever possible, the "classic" Rose-Waaler and RA tests. We found both methods easy to perform, well correlating with the semi-quantitative techniques and highly reproducible.