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Background and Aim: Over 80% (365/454) of the nation's centers participated in the Italian Society of Nephrology COVID-19 Survey. Out of 60,441 surveyed patients, 1368 were infected as of April 23rd, 2020. However, center-specific proportions showed substantial heterogeneity. We therefore undertook new analyses to identify explanatory factors, contextual effects, and decision rules for infection containment., Methods: We investigated fixed factors and contextual effects by multilevel modeling. Classification and Regression Tree (CART) analysis was used to develop decision rules., Results: Increased positivity among hemodialysis patients was predicted by center location [incidence rate ratio (IRR) 1.34, 95% confidence interval (CI) 1.20-1.51], positive healthcare workers (IRR 1.09, 95% CI 1.02-1.17), test-all policy (IRR 5.94, 95% CI 3.36-10.45), and infected proportion in the general population (IRR 1.002, 95% CI 1.001-1.003) (all p < 0.01). Conversely, lockdown duration exerted a protective effect (IRR 0.95, 95% CI 0.94-0.98) (p < 0.01). The province-contextual effects accounted for 10% of the total variability. Predictive factors for peritoneal dialysis and transplant cases were center location and infected proportion in the general population. Using recursive partitioning, we identified decision thresholds at general population incidence ≥ 229 per 100,000 and at ≥ 3 positive healthcare workers., Conclusions: Beyond fixed risk factors, shared with the general population, the increased and heterogeneous proportion of positive patients is related to the center's testing policy, the number of positive patients and healthcare workers, and to contextual effects at the province level. Nephrology centers may adopt simple decision rules to strengthen containment measures timely.

Background: Between February and April 2020, Italy experienced an overwhelming growth of the COVID-19 pandemic. Little is known, at the country level, where and how patients on renal replacement therapy (RRT) have been mostly affected., Methods: Survey of the network of Nephrology centers using a simplified 17 items electronic questionnaire designed by Italian Society of Nephrology COVID-19 Research Group. We used spatial epidemiology and geographical information systems to map SARS-CoV-2 spread among RRT patients in Italy., Results: On April 9th 2020, all nephrology centers (n = 454) listed in the DialMap database were invited to complete the electronic questionnaire. Within 11 days on average, 365 centers responded (80.4% response rate; 2.3% margin of error) totaling 60,441 RRT patients. The surveyed RRT population included 30,821 hemodialysis (HD), 4139 peritoneal dialysis (PD), and 25,481 transplanted (Tx) patients respectively. The proportion of SARS-CoV-2 positive RRT patients in Italy was 2.26% (95% CI 2.14-2.39) with significant differences according to treatment modality (p < 0.001). The proportion of patients positive for SARS-CoV-2 was significantly higher in HD (3.55% [95% CI 3.34-3.76]) than PD (1.38% [95% CI 1.04-1.78] and Tx (0.86% [95% CI 0.75-0.98]) (p < 0.001), with substantial heterogeneity across regions and along the latitude gradient (p < 0.001). In RRT patients the highest rate was in the north-west (4.39% [95% CI 4.11-4.68], followed by the north-east (IR 2.06% [1.79-2.36]), the center (0.91% [0.75-1.09]), the main islands (0.67% [0.47-0.93]), and the south (0.59% [0.45-0.75]. During the COVID-19 pandemic, among SARS-Cov-2 positive RRT patients the fatality rate was 32.8%, as compared to 13.3% observed in the Italian population as of April 23rd., Conclusions: A substantial proportion of the 60,441 surveyed RRT patients in Italy were SARS-Cov-2 positive and subsequently died during the exponential phase of COVID-19 pandemic. Infection risk and rates seems to differ substantially across regions, along geographical latitude, and by treatment modality.

Secondary hyperparathyroidism (SHP) is one of the most challenging complications in the most advanced stages of end-stage renal disease. In the last decade, newly available medical tools have greatly increased the possibilities for controlling SHP. However, one of these tools, cinacalcet, has not yet been approved 
for its use in transplanted patients and the evidence for its safety in this clinical setting is still incomplete. For these reasons, many questions still remain open for the clinical nephrologist: when to consider a parathyroidectomy (PTX)  in a patient on a waiting list for kidney transplant  (KTx); when to recommend PTX after KTx; when could a regression of parathyroid hyperplasia 
be expected at any time after KTx. In the present paper, we will briefly deal with these questions in the light of an unusual clinical case.

The discovery of the calcium-sensing receptor (CaSR) prompted the identification of substances that affect its function. Cinacalcet, for example, is a drug that allosterically modifies the receptor so as to increase its sensitivity to circulating calcium (thus the name "calcimimetic") and in this way decreases parathyroid hormone secretion. Clinical use of cinacalcet is already approved for the treatment of primary and secondary hyperparathyroidism, but research is ongoing to identify further potential actions of this drug. The effects and functions of the CaSR have been evaluated in different systems and tissues, beyond parathyroid glands, such arterial walls. A complete understanding of the properties of calcimimetics are of obvious clinical interest, since therapeutic indications may be affected accordingly.

The widely differing functions of vitamin D are based both on a wide diffusion of its specific receptor (VDR) and on the ability of many cells, in addition to renal tubular cells, to synthesize calcitriol for autocrine and paracrine functions. In the last few years, many published studies have added new insights into some important points on this topic. Recent data suggest that the control of calcitriol synthesis at tissue levels other than kidneys might differ greatly from the control system working at the renal level. Furthermore, the mechanisms by which the VDR might mediate either the genomic and nongenomic (rapid) vitamin D-mediated effects became much clearer. However, new evidence accumulated suggests that some additional receptor(s), responsive to vitamin D and different from the VDR, could play a role in the rapid response to vitamin D, probably interfering also with the genomic pathway. In this context, there are new possible interpretations of the mechanisms by which different vitamin D metabolites might express variable activities at different levels. In addition, some recent data have challenged the role of the VDR in direct parathyroid hormone (PTH) control, at least in physiological conditions, suggesting that vitamin D-mediated PTH inhibition is mainly secondary to the intestinal effect on calcium absorption. Finally, there is a renewed interest in the field of polymorphic variants in the VDR gene in relation to some clinical conditions, though the mechanisms underlining these associations are far from being clear. The present review briefly addresses all of the above points.

Aims: In recent years, treatment options for secondary hyperparathyroidism (SHPT) have increased (e.g., paricalcitol, calcimimetics). To determine the impact these new treatments have on achieving K/DOQI targets, an observational, prospective survey was undertaken., Methods: Four 6-month time-spaced surveys of 2,637 patients in 28 Italian dialysis units were performed. Patient demographic information; use of vitamin D or calcimimetics; and changes in parathyroid hormone (PTH), calcium (Ca) and phosphate (P) levels were evaluated., Results: Over the course of the survey, use of calcitriol decreased (from 62.1% at baseline to 44.5% at month 18; p<0.001), while use of paricalcitol (from 19.9% to 36.9%; p<0.001) and calcimimetics (from 6.4% to 10.8%; p<0.001) increased. This was associated with a decrease in mean PTH values (from 310.3 ± 292.4 pg/mL at baseline to 279.5 ± 250.1 pg/mL at month 18; p=0.0002), while mean Ca and P remained steady. The percentage of patients achieving K/DOQI ranges for PTH (from 26.8% at baseline to 32.0% at month 18, p<0.001), Ca (from 50.4% at baseline to 55.9% at month 18, p<0.001) and the 3 targets combined (PTH, Ca and P; from 8.8% at baseline to 11.5% at month 18, p=0.003) significantly increased (p<0.05). Despite the introduction of newer agents, two thirds of patients did not achieve target levels., Conclusions: Increased awareness and newer treatment options for chronic kidney disease patients with SHPT have changed treatment policy and number of patients achieving K/DOQI target levels in Italy. However, the majority of patients did not meet the target ranges, suggesting that new drugs and strategies are still warranted for optimal management of SHPT in chronic kidney disease.

A 56-year-old Caucasian man with non-Hodgkin's lymphoma, who had previously been treated with prolonged intensive chemotherapy, was hospitalized for an acute and reversible kidney injury of multifactorial origin. The urinary sediment examination, performed daily, demonstrated the presence of renal tubular cells and renal tubular cell casts. Surprisingly, it also showed the presence of trophozoites of the protozoan Balantidium coli, which were identified on the basis of its characteristic morphology and rapid movements across the slide, and transient leukocyturia. The patient was asymptomatic, his medical history was negative for gastrointestinal disease, and no Balantidium coli was found in the feces. In spite of this, due to the previous chemotherapy, the patient was treated with oral metrodinazole. Only one other case with Balantidium coli in the urine sediment has been described so far and this paper stresses the importance of the examination of the urinary sediment.

Hypercalcemia and hypophosphatemia are frequently observed in recipients of a kidney transplant (KTx). Hypercalcemia has been reported in up to 66% of KTx patients. Many factors have been suggested as the putative causal factors; however, the persistence of moderate-severe secondary hyperparathyroidism, associated with a change in the set-point of the Ca-controlled parathyroid hormone (PTH) secretion, is considered to play a prominent role. Hypercalcemia can negatively impact on both the graft and patient outcome, increasing the incidence of nephrocalcinosis, which can induce a worse graft outcome, inducing vascular calcifications, and increasing the incidence of pancreatitis. In addition, severe hypercalcemia after KTx often requires parathyroidectomy, which is not universally considered a safe medical solution in this clinical setting. After KTx, phosphate levels often fall below the normal range, with hypophosphatemia being observed in up to 40% of patients. The putative causal factors for this metabolic alteration are persistent hyperparathyroidism, increased levels of FGF-23, tubular damage secondary to the immunological effects, and toxic and vascular effectors. Hypophosphatemia can negatively impact on either skeletal or muscular systems, contributing to the increased incidence of bone fractures in KTx patients. The current therapeutic options should take into account an accurate pretransplant treatment and screening of the waiting-list patient and should also evaluate the efficacy and safety profile of the new pharmacological tools (calcimimetics) in comparison with the classical surgical approach (parathyroidectomy).

Background: The efficacy and safety of rituximab when not associated with other immunosuppressive therapy in induction of remission of proliferative lupus nephritis (PLN) has not until now been proven., Methods: We report on 3 patients with PLN (class IV), 1 with a nephritic flare and 2 with a proteinuric flare (all with nephrotic syndrome (NS)) treated with 3 intravenous methylprednisolone pulses for 3 consecutive days and with rituximab at day 3 and day 18 associated with oral prednisone. At the beginning of the fourth month of therapy, mycophenolate mofetil was combined with prednisone., Results: Three months after the beginning of therapy, renal function improved in the patient with the nephritic flare, and proteinuria fell to within the non-nephrotic range in all 3 patients. At the end of a follow-up of 24 months, the patient with the nephritic flare had normal renal function (serum creatinine from 1.7 to 1 mg/dL) and mild proteinuria (from 6 to 0.7 g/24 hours). The second patient was in complete remission (proteinuria from 5 to 0.127 g/24 hours) 27 months after the beginning of therapy. In the last patient, followed for 10 months, mild proteinuria persisted (from 6.6 to 0.7 g/24 hours). The therapy was well tolerated by all patients. No adverse effects occurred during the follow-up., Conclusion: Although our results must be confirmed by larger prospective studies, rituximab associated with methylprednisolone pulses without any other concomitant immunosuppressive drug seems to be effective and safe for induction therapy of severe flares of PLN.

The most frequent kidney disease associated with chronic hepatitis C virus (HCV) infection is type I membranoproliferative glomerulonephritis (MPGN) in patients with type II mixed cryoglobulinemia. The principal clinical manifestations of glomerular disease in HCV-infected patients are the presence of proteinuria and microscopic hematuria with or without impaired kidney function. Various approaches have been tried for the treatment of HCV-associated glomerulonephritis, including immunosuppressive therapy (corticosteroids and cytotoxic agents), plasma exchange and antiviral agents. Limited data exist regarding antiviral treatment of HCV-associated glomerulonephritis, whereas immunosuppressive agents have been suggested for cryoglobulinemic kidney disease. A recent meta-analysis of controlled clinical trials (CCTs) suggested that standard interferon (IFN) doses were more effective than immunosuppressive agents in lowering proteinuria of patients with HCV-related cryoglobulinemic glomerulonephritis (odds ratio 3.86; 95% confidence interval, 1.44-10.33; p=0.007). However, data for follow-up were not given. Two distinct approaches should be considered for the treatment of HCV-associated cryoglobulinemic glomerulonephritis according to the level of proteinuria and kidney failure. Preliminary studies with rituximab therapy of HCV-related cryoglobulinemic glomerulonephritis have given encouraging results, even if a point of caution is important, because rituximab use may be associated with activation of various infections, including HCV.

Background: Although an erythropoiesis-stimulating agent (ESA) is most frequently administered intravenously for treatment of anemia in patients with chronic kidney disease who are on dialysis, few studies have compared the efficacy of different intravenous (i.v.) dosing schedules., Methods: This multicenter, phase IIIb, open-label, controlled study randomized 289 stable hemodialysis patients to continue with conventional dosing of i.v. epoetin alfa or darbepoetin, or to switch to once-weekly i.v. epoetin alfa at the same cumulative weekly starting dose, to maintain hemoglobin levels at 11.0-13.0 g/dL, and within 1.0 g/dL of the baseline value. Hemoglobin levels and ESA doses were recorded every 4 weeks for 28 weeks., Results: Hemoglobin levels fell significantly and ESA doses increased significantly between baseline and week 28 (mean of week 16-28 values) in the once-weekly epoetin alfa group, compared with the conventional treatment group (p< 0.001). The adjusted difference in mean hemoglobin levels between the groups was 0.73 g/dL (greater than the threshold for therapeutic equivalence of 0.5 g/dL). The changes between groups from baseline was significant at all time points for hemoglobin levels (0.36, 0.46, 0.81, 0.87, 0.78, 0.62 and 0.49 g/dL) and from week 12 for ESA dose (718.5, 1,326.5, 1,732.0, 1,839.7 and 1,959.1 IU/week; p=0.005). Hemoglobin was maintained at the target level in 78% and 84% of patients on conventional dosing, and 67% and 64% of those on once-weekly epoetin alfa in the intention-to-treat (p=0.1) and per protocol (p=0.016) populations, respectively., Conclusions: This study did not show therapeutic equivalence of once-weekly i.v. epoetin alfa with conventional dosing regimens.

A kidney allograft recipient developed a cutaneous infection 29 months after transplantation, due to the dematiaceous fungus Alternaria infectoria on his right forearm and left leg. Since the lesions were too large to be excised, the patient was treated only with systemic itraconazole and a reduction of the immunosuppressive therapy. After 4 months, the lesions were completely healed, and no relapses were observed at follow-up of 22 months. Twenty-seven other cases of cutaneous alternariosis have been described so far in renal transplant recipients. All types of immunosuppressive treatment can be associated with Alternaria infection, for which predisposing factors are jobs with frequent contact with earth, diabetes mellitus and skin trauma. In 70% of cases the infection occurred within the first year after transplantation. More frequently the lower limbs were involved and the lesions were multiple. Alternaria alternata was the commonest causative agent, followed by Alternaria tenuissima,Alternaria infectoria and Alternaria chartarum. The treatment is far from being standardized, but the best results are obtained with the surgical excision of the lesion(s) associated with systemic antifungal therapy. Since relapses are possible, strict control of the patients over time is essential.

Therapy with i.v. calcitriol (CLT), that had been the mainstay of the cure of severe secondary hyperparathyroidism (SHPT) for many years, is often hindered by the occurrence of hypercalcemia, that requires discontinuation of the drug with consequent rebounding of the parathyroid hormone (PTH) oversecretion. To circumvent this shortcoming, CLT-analogs with less calcemic effects with respect to CLT have been developed. One of these analogs, paracalcitol (PCLT), proved to be at least as powerful as CLT in decreasing serum PTH, but it still remains endowed with some calcemic effect as the parent compound. Meanwhile, calcimimetics (CaMs) drugs targeting the calcium-sensing receptors on the PTG, have been marketed woldwide. Cinacalcet (CNC) is a CaM endowed with the unique prerogative to significantly decrease serum PTH while also decreasing serum calcium. Thus, one may attempt to speculate that CaMs may completely replace vitamin D derivatives from the therapeutic arena. Uremic patients, however, suffer from severe deprivation of biological vitamin D effects, that puts them in need of highly dosed vitamin D in order to both ameliorate their bone status and to preserve their general and cardiovascular health. Thus, a combination therapy with PCLT, which has a significant patient-survival advantage over CLT, and CNC seems to be more appropriate than only-one-drug based therapy for SHPT. Such a combination will hopefully result in a better control of SHPT, avoidance of cumbersome hypercalcemia and higher life expectancy for uremic patients than ever before.

Uremic acidosis is due to impaired excretion of ammonium ions in the presence of unchanged acid production. However, the degree of acidosis is quite variable among uremic patients and pre-dialytic bicarbonate levels are mainly independent of dialytic base supply. These observations strengthen the suggestion that extra-renal mechanisms may play a significant role in controlling acid-base balance in uremic patients. The possible effects of diet, intestine, bone, intermediate metabolism, and the global acid-base balance are discussed. The metabolic and clinical effects of mild uremic acidosis are not well defined. In fact, no long-term clinical study have produced clear evidence for increased protein catabolism in humans. Some data provide evidence for reduced bone mineral content and osteomalacic lesions in uremic patients with severe acidosis. Overall, the impact of the present dialytic techniques on acid-base control is quite small, since no major difference is observed in uremic patients treated with different dialytic schedules. Furthermore, the base supply by dialysis does not seem to represent the main mechanism for acid-base correction by dialysis. In conclusion, at present time, metabolic acidosis of uremic patients is often mild and not accompanied by major symptoms. Probably, more attention needs to be paid to the possible noxious effect of over-correction of acidosis.