Sex differences in clinical outcomes in Japanese incident dialysis patients: a prospective observational multicenter study.

BACKGROUND: A Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown a one-to-one male-to-female mortality ratio, notwithstanding the statistically longer life expectancy of women in the general population. This finding contrasts with the recent report that Japanese women on dialysis treatment have a more favorable longevity. Accordingly, we further investigated the clinical procedures and outcomes to clarify the sex differences in Japanese patients undergoing dialysis treatment. METHODS: Subjects were incident dialysis patients who participated in a multicenter prospective cohort study from October 2011 to September 2013. The all-cause mortality was analyzed by a Cox proportional hazard regression model and studied separately in women and men with or without cardiovascular disease (CVD) at baseline. RESULTS: Overall, 492 (32.3%) of the 1520 test subjects were women. All-cause mortality was higher in men (28.6%) than in women (19.9%, p < 0.001). Female sex (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.54-0.90) and history of CVD (HR: 1.51, 95% CI: 1.18-1.95) were independent predictors of all-cause mortality. In patients without CVD, female gender was strong independent contributor (HR = 0.46, 95% CI: 0.30-0.70, p < 0.001). In contrast, patients with CVD showed no difference in survival between the sexes (HR: 0.92, 95% CI: 0.67-1.24, p = 0.597). CONCLUSION: Our study demonstrated that women undergoing chronic dialysis therapy had a lower mortality risk than men. However, complication with CVD canceled out the survival advantage in Japanese women on chronic dialysis. We should reevaluate the risk of women with CVD undergoing dialysis and apply the optimal care for CVD.

Deep learning analysis of clinical course of primary nephrotic syndrome: Japan Nephrotic Syndrome Cohort Study (JNSCS).

BACKGROUND: Prognosis of nephrotic syndrome has been evaluated based on pathological diagnosis, whereas its clinical course is monitored using objective items and the treatment strategy is largely the same. We examined whether the entire natural history of nephrotic syndrome could be evaluated using objective common clinical items. METHODS: Machine learning clustering was performed on 205 cases from the Japan Nephrotic Syndrome Cohort Study, whose clinical parameters, serum creatinine, serum albumin, dipstick hematuria, and proteinuria were traceable after kidney biopsy at 5 measured points up to 2 years. The clinical patterns of time-series data were learned using long short-term memory (LSTM)-encoder-decoder architecture, an unsupervised machine learning classifier. Clinical clusters were defined as Gaussian mixture distributions in a two-dimensional scatter plot based on the highest log-likelihood. RESULTS: Time-series data of nephrotic syndrome were classified into four clusters. Patients in the fourth cluster showed the increase in serum creatinine in the later part of the follow-up period. Patients in both the third and fourth clusters were initially high in both hematuria and proteinuria, whereas a lack of decline in the urinary protein level preceded the worsening of kidney function in fourth cluster. The original diseases of fourth cluster included all the disease studied in this cohort. CONCLUSIONS: Four kinds of clinical courses were identified in nephrotic syndrome. This classified clinical course may help objectively grasp the actual condition or treatment resistance of individual patients with nephrotic syndrome.

Better remission rates in elderly Japanese patients with primary membranous nephropathy in nationwide real-world practice: The Japan Nephrotic Syndrome Cohort Study (JNSCS).

BACKGROUND: The aim of the present study was to clarify the prevalence of immunosuppressive drug use and outcomes in elderly and non-elderly patients with primary membranous nephropathy (MN) in nationwide real-world practice in Japan. PATIENTS AND METHODS: Between 2009 and 2010, 374 patients with primary nephrotic syndrome were enrolled in the cohort study (The Japan Nephrotic Syndrome Cohort Study, JNSCS), including 126 adult patients with MN. Their clinical characteristics were compared with those of nephrotic patients with primary MN registered in a large nationwide registry (The Japan Renal Biopsy Registry, J-RBR). Outcomes and predictors in the elderly (≥ 65 years) and non-elderly groups were identified. RESULTS: Similar clinical characteristics were observed in JNSCS patients and J-RBR patients (n = 1808). At the early stage of 1 month, 84.1% of patients were treated with immunosuppressive therapies. No significant differences were observed in therapies between age groups. However, elderly patients achieved complete remission (CR) more frequently than non-elderly patients, particularly those treated with therapies that included corticosteroids. No significant differences were noted in serum creatinine (sCr) elevations at 50 or 100%, end-stage kidney disease, or all-cause mortality between age groups. Corticosteroids were identified as an independent predictor of CR (HR 2.749, 95%CI 1.593-4.745, p = 0.000) in the multivariate Cox's model. sCr levels, hemoglobin levels, immunosuppressants, clinical remission, and relapse after CR were independent predictors of sCr × 1.5 or × 2.0. CONCLUSION: Early immunosuppressive therapy including corticosteroids for primary MN showed better remission rates in elderly patients in a nationwide cohort study.

Incidence of remission and relapse of proteinuria, end-stage kidney disease, mortality, and major outcomes in primary nephrotic syndrome: the Japan Nephrotic Syndrome Cohort Study (JNSCS).

BACKGROUND: Despite recent advances in immunosuppressive therapy for patients with primary nephrotic syndrome, its effectiveness and safety have not been fully studied in recent nationwide real-world clinical data in Japan. METHODS: A 5-year cohort study, the Japan Nephrotic Syndrome Cohort Study, enrolled 374 patients with primary nephrotic syndrome in 55 hospitals in Japan, including 155, 148, 38, and 33 patients with minimal change disease (MCD), membranous nephropathy (MN), focal segmental glomerulosclerosis (FSGS), and other glomerulonephritides, respectively. The incidence rates of remission and relapse of proteinuria, 50% and 100% increases in serum creatinine, end-stage kidney disease (ESKD), all-cause mortality, and other major adverse outcomes were compared among glomerulonephritides using the Log-rank test. Incidence of hospitalization for infection, the most common cause of mortality, was compared using a multivariable-adjusted Cox proportional hazard model. RESULTS: Immunosuppressive therapy was administered in 339 (90.6%) patients. The cumulative probabilities of complete remission within 3 years of the baseline visit was ≥ 0.75 in patients with MCD, MN, and FSGS (0.95, 0.77, and 0.79, respectively). Diabetes was the most common adverse events associated with immunosuppressive therapy (incidence rate, 71.0 per 1000 person-years). All-cause mortality (15.6 per 1000 person-years), mainly infection-related mortality (47.8%), was more common than ESKD (8.9 per 1000 person-years), especially in patients with MCD and MN. MCD was significantly associated with hospitalization for infection than MN. CONCLUSIONS: Patients with MCD and MN had a higher mortality, especially infection-related mortality, than ESKD. Nephrologists should pay more attention to infections in patients with primary nephrotic syndrome.

Regional variations in immunosuppressive therapy in patients with primary nephrotic syndrome: the Japan nephrotic syndrome cohort study.

BACKGROUND: The lack of high-quality clinical evidences hindered broad consensus on optimal therapies for primary nephrotic syndromes. The aim of the present study was to compare prevalence of immunosuppressive drug use in patients with primary nephrotic syndrome across 6 regions in Japan. METHODS: Between 2009 and 2010, 380 patients with primary nephrotic syndrome in 56 hospitals were enrolled in a prospective cohort study [Japan Nephrotic Syndrome Cohort Study (JNSCS)], including 141, 151, and 38 adult patients with minimal change disease (MCD), membranous nephropathy (MN), and focal segmental glomerulosclerosis (FSGS), respectively. Their clinical characteristics were compared with those of patients registered in a large nationwide registry of kidney biopsies [Japan Renal Biopsy Registry (J-RBR)]. The regional prevalence of use of each immunosuppressive drug was assessed among adult MCD, MN, and FSGS patients who underwent immunosuppressive therapy in the JNSCS (n = 139, 127, and 34, respectively). Predictors of its use were identified using multivariable-adjusted logistic regression models. RESULTS: The clinical characteristics of JNSCS patients were comparable to those of J-RBR patients, suggesting that the JNSCS included the representatives in the J-RBR. The secondary major immunosuppressive drugs were intravenous methylprednisolone [n = 33 (24.6%), 24 (19.7%), and 9 (28.1%) in MCD, MN, and FSGS, respectively] and cyclosporine [n = 25 (18.7%), 62 (50.8%), and 16 (50.0%), respectively]. The region was identified as a significant predictor of use of intravenous methylprednisolone in MCD and MN patients. CONCLUSION: Use of intravenous methylprednisolone for MCD and MN differed geographically in Japan. Its efficacy should be further evaluated in a well-designed trial.

Aichi cohort study of the prognosis in patients newly initiated into dialysis (AICOPP): baseline characteristics and trends observed in diabetic nephropathy.

BACKGROUND: Over 300,000 patients receive maintenance dialysis in Japan; managing these patients is extremely important. This study aimed to report on prior management of chronic kidney diseases and prognostication after dialysis initiation. PATIENTS AND METHODS: Seventeen institutions participated in the Aichi cohort study of prognosis in patients newly initiated into dialysis and recruited patients over a period of 2 years. Exclusion criteria were (1) patients under 20 years; (2) patients who died before hospital discharge; and (3) patients who could not provide consent. RESULT: Here, we showed data on dialysis initiation time. Of 1524 patients with mean age of 67.5 ± 13.0 years, 659 patients were put on dialysis following diabetic nephropathy diagnosis. At dialysis initiation time, creatinine and estimated glomerular filtration rate levels were 8.97 ± 3.21 mg/dl and 5.45 ± 2.22 ml/min/1.73 m2, respectively. Medications taken were angiotensin II receptor blockers in 866; angiotensin-converting enzyme inhibitors in 135; calcium antagonist in 1202; and diuretics, alone or in combination, in 1059. Among patients with diabetic nephropathy, many had increased body weight and systolic blood pressure and were taking loop and thiazide diuretics at dialysis initiation time. Many patients with diabetic nephropathy had coronary artery disease and percutaneous coronary intervention. CONCLUSION: Many patients with diabetic nephropathy who registered for this study had coronary artery disease and problems with excess body fluid. Further analyses may clarify how underlying conditions and disease management before and after dialysis initiation affect prognosis.

Recent analysis of status and outcomes of peritoneal dialysis in the Tokai area of Japan: the second report of the Tokai peritoneal dialysis registry.

BACKGROUND: Early withdrawal within 3 years after starting peritoneal dialysis (PD) and PD-related peritonitis have been major obstacles preventing increases in the population of PD patients. To address these problems, we implemented education programs for medical staff. This study analyzed the recent status and outcomes of PD therapy, focusing on findings such as the incidence and prognosis of peritonitis as of 5 years after our last study. METHODS: We investigated background, laboratory data and status of PD therapy, reasons for withdrawal from PD and incidental statements on peritonitis from 2010 to 2012 (R2), and compared findings with those from our last study of 2005-2007 (R1). RESULTS: Early PD therapy withdrawal in R2 clearly improved to 44.7 %, compared with 50.9 % in R1. Peritonitis incidence improved slightly from once per 42.8 months/patient in R1 to once per 47.3 months/patient in R2. Notably, PD-related peritonitis as a cause of mortality improved markedly in R2, but outcomes of PD-related peritonitis did not change significantly between R1 and R2. In contrast, social problems increased as a reason for withdrawal from PD therapy. CONCLUSION: Our efforts at education might have been useful for improving early withdrawal from PD and deaths attributable to PD-related peritonitis. However, since improvements to incidence of PD-related peritonitis were limited by education, further improvement in PD-related peritonitis incidence requires development of new sterilized connecting systems during PD-bag exchanges to decrease PD-related peritonitis opportunities. Construction of medical support systems to address social problems is required to maintain long-term PD therapy.

Long-term effects of spironolactone in peritoneal dialysis patients.

ESRD treated with dialysis is associated with increased left ventricular hypertrophy, which, in turn, is related to high mortality. Mineralocorticoid receptor antagonists improve survival in patients with chronic heart failure; however, the effects in patients undergoing dialysis remain uncertain. We conducted a multicenter, open-label, prospective, randomized trial with 158 patients receiving angiotensin-converting enzyme inhibitor or angiotensin type 1 receptor antagonist and undergoing peritoneal dialysis with and without (control group) spironolactone for 2 years. As a primary endpoint, rate of change in left ventricular mass index assessed by echocardiography improved significantly at 6 (P=0.03), 18 (P=0.004), and 24 (P=0.01) months in patients taking spironolactone compared with the control group. Rate of change in left ventricular ejection fraction improved significantly at 24 weeks with spironolactone compared with nontreatment (P=0.02). The benefits of spironolactone were clear in patients with reduced residual renal function. As secondary endpoints, renal Kt/V and dialysate-to-plasma creatinine ratio did not differ significantly between groups during the observation period. No serious adverse effects, such as hyperkalemia, occurred. In this trial, spironolactone prevented cardiac hypertrophy and decreases in left ventricular ejection fraction in patients undergoing peritoneal dialysis, without significant adverse effects. Further studies, including those to determine relative effectiveness in women and men and to evaluate additional secondary endpoints, should confirm these data in a larger cohort.

IgA nephropathy diagnosed as a result of acute exacerbation due to G-CSF administration.

Granulocyte colony-stimulating factor (G-CSF) is commonly used to stimulate bone marrow production. G-CSF is usually safe but sometimes causes serious adverse effects and, in rare cases, exacerbates glomerulonephritis. We report a case of immunoglobulin A (IgA) nephropathy that was aggravated by G-CSF. A 56-year-old Japanese man with no relevant medical history was admitted to our hospital as a donor of peripheral blood stem cells (PBSCs) for transplantation. To mobilize PBSCs, he received subcutaneous G-CSF (lenograstim), 500 µg for 4 days. Three days after the first dose of lenograstim, gross hematuria appeared, and after administration on the fourth day, renal dysfunction and nephrotic-range proteinuria were observed. Renal biopsy and light microscopic study revealed mild mesangial proliferation with expansion in association with the presence of cellular segmental crescents. Immunofluorescence study revealed diffuse, granular staining in the mesangium for IgA, complement component 3 (C3), and lambda light chains. We diagnosed highly active IgA nephropathy and initiated treatment with prednisolone and azathioprine. Three months later, renal function returned to normal. Screening for hidden chronic glomerulonephritis should be performed when G-CSF is administered, as in PBSC donors. Immunosuppressant therapy, such as prednisolone or azathioprine, is considered for exacerbations of highly active glomerulonephritis.

A case of juvenile-onset fibrillary glomerulonephritis diagnosed by mass spectrometry and immunohistochemistry of DNAJB9.

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease. FGN is characterized by the deposition of randomly arranged, nonbranching microfibrils in the mesangium and glomerular basement membrane. The discovery of DNAJ homolog subfamily B member 9 (DNAJB9) in 2017 was a breakthrough, and DNAJB9 has been proven to be extremely useful for the definitive diagnosis of FGN. While FGN often occurs in middle-aged individuals, this case was diagnosed at a relatively young age of 17. We performed renal biopsy, and light microscopic study revealed mesangial proliferation with expansion and subepithelial deposits. Electron microscopic study showed glomerular deposition of randomly oriented nonbranching fibrils with a mean of 20 nm. However, direct first scarlet stain for amyloidosis was weakly positive. Therefore, we confirmed the diagnosis of FGN and eliminated the presence of amyloidosis with mass spectrometry. This is the first case in Japan in which the complication of amyloidosis was ruled out with mass spectrometry and FGN was diagnosed using immunostaining and mass spectrometry of DNAJB9. We began treatment with cyclosporine A. One and a half years after the start of the treatment, kidney function continues to be normal.

Time to remission of proteinuria and incidence of relapse in patients with steroid-sensitive minimal change disease and focal segmental glomerulosclerosis: the Japan Nephrotic Syndrome Cohort Study.

BACKGROUND: Minimal change disease (MCD) is characterized by a nephrotic syndrome usually steroid-sensitive and a high incidence of relapse of proteinuria. Previous cohort studies have reported conflicting results regarding the association between the time to remission and incidence of relapse. METHODS: This multicenter prospective cohort study included 102 adult patients with steroid-sensitive MCD or focal segmental glomerulosclerosis from a 5-year cohort study of primary nephrotic syndrome, the Japan Nephrotic Syndrome Cohort Study, who achieved remission of proteinuria within 2 months of immunosuppressive therapy (IST). The association between the time to remission of proteinuria after immunosuppressive therapy and incidence of relapse was assessed using Cox proportional hazards models adjusted for clinically relevant factors. RESULTS: Remission was observed at 3-7, 8-14, 15-21, 22-28, and 30-56 days after initiation of immunosuppressive therapy in 17 (16.7%), 37 (36.3%), 21 (20.6%), 13 (12.7%), and 14 (13.7%) patients, respectively. During a median observation period of 2.3 years after the end of the 2nd month after initiation of immunosuppressive therapy, 46 (45.1%) patients relapsed. The time to remission was associated with the incidence of relapse in an inverse U-shaped pattern (multivariable-adjusted hazard ratios [95% confidence intervals] of the time to remission of 3-7, 8-14, 15-21, 22-28, 30-56 days: 1.00 [reference], 1.76 [0.56, 5.51], 6.06 [1.85, 19.80], 5.46 [1.44, 20.64], and 2.19 [0.52, 9.30], respectively). CONCLUSION: The time to remission was identified as a significant predictor of relapse in steroid-sensitive patients.

Predictors of early remission of proteinuria in adult patients with minimal change disease: a retrospective cohort study.

Previous studies reported conflicting results regarding an association between serum albumin concentration and the cumulative incidence of remission of proteinuria in adult patients with minimal change disease (MCD). The present study aimed to clarify the clinical impact of serum albumin concentration and the cumulative incidence of remission and relapse of proteinuria in 108 adult patients with MCD at 40 hospitals in Japan, who were enrolled in a 5-year prospective cohort study of primary nephrotic syndrome, the Japan Nephrotic Syndrome Cohort Study (JNSCS). The association between serum albumin concentration before initiation of immunosuppressive treatment (IST) and the cumulative incidence of remission and relapse were assessed using multivariable-adjusted Cox proportional hazards models. Remission defined as urinary protein < 0.3 g/day (or g/gCr) was observed in 104 (96.3%) patients. Of 97 patients with remission within 6 month of IST, 42 (43.3%) developed relapse defined as ≥ 1.0 g/day (or g/gCr) or dipstick urinary protein of ≥ 2+. Serum albumin concentration was significantly associated with remission (multivariable-adjusted hazard ratio [95% confidence interval] per 1.0 g/dL, 0.57 [0.37, 0.87]), along with eGFR (per 30 mL/min/1.73 m2: 1.43 [1.08, 1.90]), whereas they were not associated with relapse. A multivariable-adjusted model showed that patients with high eGFR level (≥ 60 mL/min/1.73 m2) and low albumin concentration (≤ 1.5 g/dL) achieved significantly early remission, whereas those with low eGFR (< 60 mL/min/1.73 m2) and high albumin concentration (> 1.5 g/dL) showed significantly slow remission. In conclusion, lower serum albumin concentration and higher eGFR were associated with earlier remission in MCD, but not with relapse.

The effectiveness and safety of computed tomographic peritoneography and video-assisted thoracic surgery for hydrothorax in peritoneal dialysis patients: A retrospective cohort study in Japan.

INTRODUCTION: Albeit uncommon, hydrothorax is an important complication of peritoneal dialysis (PD). Due to paucity of evidence for optimal treatment, this study aimed to evaluate the effectiveness and safety of computed tomographic (CT) peritoneography and surgical intervention involving video-assisted thoracic surgery (VATS) for hydrothorax in a retrospective cohort of patients who underwent PD in Japan. METHODS: Of the 982 patients who underwent PD from six centers in Japan between 2007 and 2019, 25 (2.5%) with diagnosed hydrothorax were enrolled in this study. PD withdrawal rates were compared between patients who underwent VATS for diaphragm repair (surgical group) and those who did not (non-surgical group) using the Kaplan-Meier method and log-rank test. RESULTS: The surgical and non-surgical groups comprised a total of 11 (44%) and 14 (56%) patients, respectively. Following hydrothorax diagnosis by thoracentesis and detection of penetrated sites on the diaphragm using CT peritoneography, VATS was performed at a median time of 31 days (interquartile range [IQR], 20-96 days). During follow-up (median, 26 months; IQR, 10-51 months), 9 (64.3%) and 2 (18.2%) patients in the non-surgical and surgical groups, respectively, withdrew from PD (P = 0.021). There were no surgery-related complications or hydrothorax relapse in the surgical group. CONCLUSIONS: This study demonstrated the effectiveness and safety of CT peritoneography and VATS for hydrothorax. This approach may be useful in hydrothorax cases to avoid early drop out of PD and continue PD in the long term. Further studies are warranted to confirm these results.

Effects of Sustained-Release Beraprost in Patients With Primary Glomerular Disease or Nephrosclerosis: CASSIOPEIR Study Results.

TRK-100STP, a sustained-release preparation of the orally active prostacyclin analogue beraprost sodium, targets renal hypoxia. This study aimed to show the superiority of TRK-100STP over placebos in patients with chronic kidney disease (with either primary glomerular disease or nephrosclerosis) to determine the recommended dose. CASSIOPEIR (Chronic Renal Failure Asian Study with Oral PGI2 Derivative for Evaluating Improvement of Renal Function) was a randomized, double-blind, placebo-controlled study conducted at 160 sites in seven Asia-Pacific countries and regions. Eligible patients (n = 892) were randomized to TRK-100STP 120, 240 µg, or placebo for a treatment period of up to 4 years. The primary efficacy endpoint was time to first occurrence of a renal composite: doubling of serum creatinine or occurrence of end-stage renal disease. No significant differences were observed in composite endpoints between TRK-100STP and placebo (P = 0.5674). Hazard ratios (95% CI) in the TRK-100STP 120 and 240 µg vs. placebo groups were 0.98 (0.78, 1.22) and 0.91 (0.72, 1.14), respectively. The overall incidence of adverse events and adverse drug reactions was comparable between treatment arms.

Two brothers with collagenofibrotic glomerulopathy.

Collagenofibrotic glomerulopathy is a rare glomerular disease characterized by extensive accumulation of atypical type III collagen fibers within the mesangial matrix and subendothelial space. Laboratory evaluation of this disease shows a marked increase in serum procollagen III peptide (P III P) levels. Here, we report the case of two brothers with collagenofibrotic glomerulopathy confirmed by histology. Patient 1 presented with proteinuria and hypertension and patient 2 presented with nephrotic-range proteinuria. Immunohistochemistry revealed strong staining for antibodies to type III collagen in the widened subendothelial spaces in both patients. Electron microscopy revealed numerous collagenous fibers in the mesangium and subendothelial space. P III P levels were elevated in both patients. Most reported cases of collagenofibrotic glomerulopathy, including the adult-onset type, have been sporadic. Within the limits of our literature search, this is only the third report of adult siblings with collagenofibrotic glomerulopathy confirmed by histology. This report indicates that it may be beneficial to measure serum P III P levels in the siblings of patients diagnosed with adult-onset collagenofibrotic glomerulopathy.

Nephrogenic diabetes insipidus associated with hemochromatosis.

Although hemochromatosis is one of the most common genetic disorders in humans, the clinical information on iron-induced renal impairment is limited. We describe the clinical features of nephrogenic diabetes insipidus (NDI) observed in a case of hemochromatosis. A 57-year-old diabetic man was admitted to the hospital with a 6-month history of persistent polyuria, which had been sustained after glycemic optimization with insulin therapy and resulted in hepatic coma. Despite sufficient basal excretion of arginine vasopressin, impaired urinary concentrating capacity was observed, which could not be corrected by supraphysiologic doses of exogenous arginine vasopressin. Histochemical investigations showed widely distributed iron deposition in hepatocytes and moderately increased iron deposits in the tubular epithelium of distal urinary tubules and collecting ducts, suggesting that iron deposition resulting from hemochromatosis leads to NDI. This may be the first case report of NDI associated with hemochromatosis in humans. More attention should be paid to latent NDI as another complication of hemochromatosis.

Successful treatment of refractory gout using combined therapy consisting of febuxostat and allopurinol in a patient with chronic renal failure.

Gouty arthritis is a metabolic disorder associated with hyperuricemia. Despite the development of novel pharmacotherapies, some hyperuricemia patients are drug refractory and develop gout. A 74-year-old man with frequent gouty attacks and chronic renal failure presented with asymmetrical polyarthritis affecting multiple joints. The diagnosis of gout was confirmed based on the presence of monosodium urate crystals in the patient's right wrist. The administration of systemic corticosteroids relieved the joint inflammation and pain; however, the urate level increased to 28 mg/dL and the gout attacks recurred. Combined allopurinol, febuxostat, and benzbromarone therapy reduced the urate level to <6 mg/dL, and the attacks gradually declined. This is the first report of two xanthine oxidase inhibitors being used to treat refractory gout.