Effect of Dapagliflozin on Serum Uric Acid Levels in Patients with Advanced Chronic Kidney Disease

Objective Sodium-glucose cotransporter 2 (SGLT2) inhibitors, which are hypoglycemic agents, have been shown to be cardioprotective through a variety of mechanisms, and the effect of lowering uric acid (UA) levels may be one of the mechanisms. In the present retrospective study, we investigated the changes in serum UA levels in patients with chronic kidney disease (CKD) treated with SGLT2 inhibitors. Methods We included 31 patients with CKD who were newly started on dapagliflozin for renal protection and evaluated trends in various parameters, including serum UA levels and UA excretion from urine. Results The patients' median age was 71 years old, 20 patients were men, 7 patients had diabetes, and the median estimated glomerular filtration rate was 33.9 mL/min/1.73 m2 (CKD stage 3: 21 cases, stage 4: 10 cases). The differences in UA and fractional excretion of UA after three weeks and three months of prescription showed significantly decreased UA values and an increased fractional excretion of UA. Conclusion Our findings suggest that dapagliflozin can lower serum UA levels via increased UA excretion, even in patients with advanced CKD.

Prognostic Implications of Urinary Potassium to Creatinine Ratio in Patients With Predialysis Chronic Kidney Disease: A Cohort Study

OBJECTIVES

Although a low or high serum potassium level in chronic kidney disease (CKD) is associated with worsening renal function and increased cardiovascular disease (CVD) events, urinary potassium excretion has been found to predict adverse health outcomes with conflicting results. We conducted a cohort study to determine whether urinary potassium to creatinine (K/Cr) ratio is an independent risk for further deterioration in renal function or increased CVD events.

METHODS

We identified 650 predialysis patients with CKD hospitalized for an educational program regarding CKD between January 2010 and December 2018. The study outcomes were CKD progression and incident CVD events, with baseline urinary K/Cr ratio categorized into quartiles-Q1, < 19.8; Q2, 19.9-27.7; Q3, 27.8-37.9; and Q4, > 38.0.

RESULTS

During follow-up (median, 35 months), 509 CKD progressions and 129 incident CVD events were identified. Sixty two patients died during follow-up. Multivariate Cox proportional hazard model showed that after adjustment for demographic factors and laboratory data, patients in Q1 had a 2.02-fold higher risk of worsening renal function than those in Q4 (95% confidence interval, 1.50-2.71; P < .001), whereas urinary K/Cr ratio had no association with the incidence of CVD events. Similarly, inverse probability weighting analysis showed an increased risk of CKD progression in the lowest quartile. Furthermore, the association between low fractional excretion of potassium and worsening renal function was confirmed.

CONCLUSION

A low urinary K/Cr ratio is independently associated with worsening renal function but not with a risk of incident CVD event in predialysis patients with CKD.

MO465PROGNOSTIC IMPLICATION OF URINARY POTASSIUM EXCRETION IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Background and Aims

Plasma potassium levels are impacted by decreased kidney function and are known to be associated with increased mortality, adverse cardiovascular events and adverse kidney events. However, the prognostic implication of urinary potassium is unclear.

Method

We conducted an observational study of 1102 patients with chronic kidney disease (CKD) who were hospitalized between 2010 and 2018. The expected primary outcomes were all-cause mortality, adverse cardiovascular events and CKD progression. CKD progression was defined as a 30% increase in serum creatinine, the initiation of maintenance dialysis or the need for kidney transplantation. The Cox proportional hazards model was used to analyse the association between urinary potassium excretion and adverse clinical outcomes after adjustment for potential confounders.

Results

At baseline, 66% of the patients were men, with a median age of 72 years (interquartile range or IQR, 64–79 years); 61% of the patients were diabetic, and 54% of them were hypertensive. The median values for estimated glomerular filtration rate (eGFR) was 12 mL/min/1.73m2 (IQR, 8–18), serum potassium 4.5 mmol/L (IQR, 4.1–5.1) and urinary potassium/creatinine ratio (UK/Cr) 27 mmol/gCr (IQR, 20–38). Over a median follow-up period of 2.6 years (IQR 0.2–4.5), the number of all-cause deaths was 87. There were 171 cases of cardiovascular events and 860 cases of CKD progression. After adjusting for the eGFR, serum potassium level, proteinuria, renin–angiotensin system inhibitors, diuretics and other potential confounders, UK/Cr was found to be neither significantly associated with all-cause mortality nor with adverse cardiovascular events. However, a low UK/Cr was associated with an increased risk of CKD progression (adjusted hazard ratio [95% confidence interval] for the first, second and third quartiles, compared with the fourth quartile, were as follows: 2.09 [1.43-3.06], 1.33 [0.96-1.86] and 1.05 [0.75-1.46])

Conclusion

A low UK/Cr might be an independent risk factor for poor renal outcome.

MO051EFFECT OF TOLVAPTAN ON THE SUPPRESSION OF TOTAL KIDNEY VOLUME INCREASE IN PATIENTS WITH MODERATE-TO-SEVERE RENAL DYSFUNCTION IN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Background and Aims

Tolvaptan (TV) slows down the increase in total kidney volume (TKV) in patients with autosomal dominant polycystic kidney disease (ADPKD). The efficacy of TV in patients with moderate-to-severe renal dysfunction (RD) in ADPKD remains unknown.

Method

This was a single-centre retrospective study involving 27 patients with ADPKD who took TV and visited our hospital in the past six years. The participants were divided into two groups: the normal-to-mild RD (estimated glomerular filtration rate (eGFR) ≥ 45mL/min/1.73m2) group and the moderate-to-severe RD (eGFR &lt; 45mL/min/1.73m2) group. Treatment effects were evaluated using ΔTKV, which was calculated as post-/pre-treatment annual TKV change. Continuous variables are presented using the median [interquartile range].

Results

The moderate-to-severe RD group comprised 11 patients. Baseline characteristics of the normal-to-mild vs. moderate-to-severe RD group were as follows: eGFR, 56 [50–69] vs. 29 [24–38] mL/min/1.73m2; age, 48 [39–55] vs. 49 [43–58] years; male gender, 57% vs. 36%; body mass index (BMI) , 26 [23–28] vs. 24 [22–27] kg/m2; TKV 1700 [1084–2574] vs. 1827 [1331–2424] mL; family history of ADPKD, 100% vs. 82%; history of cerebral aneurysm, 19% vs. 36%; hypertension, 81% vs. 82%; hyperuricemia, 13% vs. 27%; dyslipidaemia, 19% vs. 18%; diabetes, 6.1% vs. 9.1% and systolic blood pressure (sBP) on admission 138 [129–144] vs. 131 [128-137] mmHg. No significant differences were noted in all these parameters, except for renal function. The starting dose of TV was 60 mg/day in all cases (0.9 [0.7–1.0] vs. 0.9 [0.8–1.1] mg/kg; P = 0.35). Urine volume (7.5 [5.7–9.6] vs. 4.0 [3.3–4.7] L/day; P = 0.006) and urinary sodium excretion (163 [126–226] vs. 89 [81–120] mEq/day; P = 0.003) were higher in the normal-to-mild RD group. Between the groups, there were no differences in urine protein (0.12 [0.0–0.3] vs. 0.16 [0.08–0.29] g/day; P = 0.31) and ΔeGFR (98% [88–123] vs. 106% [102–112]; P = 0.45), which was calculated as post-/pre-treatment annual eGFR change. Although both groups experienced the therapeutic effects of TV, the efficacy was poorer in the moderate-to-severe RD group (ΔTKV, 82% [76–85] vs. 96% [86–97]; P = 0.001).

Conclusion

The efficacy of TV patients with moderate-to-severe RD in ADPKD might be modest.

New selectivity index calculated using protein fraction as a substitute for the conventional selectivity index

BACKGROUND

Selectivity index (SI) of proteinuria, calculated using the clearance ratio of immunoglobulin G to transferrin, predicts the response to glucocorticoids in patients with nephrotic syndrome. However, there is disagreement regarding the suitability of SI. Therefore, alternate indices should be considered. This study investigated whether or not selectivity index protein fraction (SIPF) was inferior to SI for the prediction of the response to glucocorticoids.

METHODS

Forty-nine patients with nephrotic syndrome were evaluated. On the basis of molecular weight and protein fraction, as an inexpensive substitute for SI, the clearance ratio of the albumin to γ fractions measured in serum and urine protein fractions was defined as SIPF. The quality of SIPF was examined. Moreover, the best cutoff value of SIPF was determined; and SIPF distribution, according to histopathological diagnosis by renal biopsy, was examined.

RESULTS

SIPF was strongly correlated with SI (r = 0.79, P < 0.001). The area under the receiver operating characteristic (ROC) curve of SIPF and SI was not significantly different (P = 0.18). The best cutoff value of SIPF was 0.45. In the group with SIPF > 0.45, only two patients with minimal change disease (MCD) achieved complete remission. In the group with SIPF ≤ 0.45, all patients with MCD achieved complete remission, although eight patients with other histopathological diagnoses did not achieve complete remission.

CONCLUSIONS

Analysis of protein fractions as a substitute for SI may be useful for predicting response to glucocorticoids in patients with nephrotic syndrome.

Diffusion tensor tractography of the lumbar nerves before a direct lateral transpsoas approach to treat degenerative lumbar scoliosis

OBJECTIVE

The purpose of this study was to determine the relationship between vertebral bodies, psoas major morphology, and the course of lumbar nerve tracts using diffusion tensor imaging (DTI) before lateral interbody fusion (LIF) to treat spinal deformities.

METHODS

DTI findings in a group of 12 patients (all women, mean age 74.3 years) with degenerative lumbar scoliosis (DLS) were compared with those obtained in a matched control group of 10 patients (all women, mean age 69.8 years) with low-back pain but without scoliosis. A T2-weighted sagittal view was fused to tractography from L3 to L5 and separated into 6 zones (zone A, zones 1-4, and zone P) comprising equal quarters of the anteroposterior diameters, and anterior and posterior to the vertebral body, to determine the distribution of nerves at various intervertebral levels (L3-4, L4-5, and L5-S1). To determine psoas morphology, the authors examined images for a rising psoas sign at the level of L4-5, and the ratio of the anteroposterior diameter (AP) to the lateral diameter (lat), or AP/lat ratio, was calculated. They assessed the relationship between apical vertebrae, psoas major morphology, and the course of nerve tracts.

RESULTS

Although only 30% of patients in the control group showed a rising psoas sign, it was present in 100% of those in the DLS group. The psoas major was significantly extended on the concave side (AP/lat ratio: 2.1 concave side, 1.2 convex side). In 75% of patients in the DLS group, the apex of the curve was at L2 or higher (upper apex) and the psoas major was extended on the concave side. In the remaining 25%, the apex was at L3 or lower (lower apex) and the psoas major was extended on the convex side. Significant anterior shifts of lumbar nerves compared with controls were noted at each intervertebral level in patients with DLS. Nerves on the extended side of the psoas major were significantly shifted anteriorly. Nerve pathways on the convex side of the scoliotic curve were shifted posteriorly.

CONCLUSIONS

A significant anterior shift of lumbar nerves was noted at all intervertebral levels in patients with DLS in comparison with findings in controls. On the convex side, the nerves showed a posterior shift. In LIF, a convex approach is relatively safer than an approach from the concave side. Lumbar nerve course tracking with DTI is useful for assessing patients with DLS before LIF.

Anti-mitochondria antibody-related tubulointerstitial nephritis accompanied by severe hypokalemic paralysis

A 47-year-old man presented with severe hypokalemic paralysis and respiratory failure. A large amount of potassium was administered along with providing intensive care, and his condition improved. Hypokalemia was attributed to increased urinary potassium excretion. A kidney biopsy was performed to make a definitive histological diagnosis. It revealed acute tubulointerstitial nephritis (TIN). After the diagnosis, prednisolone was administered, and the TIN gradually improved. From the clinical course and laboratory findings, the TIN was presumed to be an autoimmune disorder. Further specific autoantibody tests were positive for anti-mitochondrial antibody (AMA), which has been gaining increasing attention in regard to TIN. In addition, all previous cases of TIN associated with AMA have affected females. The detailed pathogenetic mechanisms are as yet unclear and require further investigation.

Motor vehicle accidents in Parkinson's disease: A questionnaire study

OBJECTIVES

Few studies have investigated the risk factors for motor vehicle accidents (MVA) in individuals with Parkinson's disease (PD) in Japan.

MATERIALS AND METHODS

We sent an anonymous questionnaire to 1417 patients with PD who had received medical care certificates for Intractable Diseases during the 2014 fiscal year from the Aomori Prefectural Government in Japan. Data from patients with PD who previously or currently held a driving license at the time of the survey were analyzed.

RESULTS

Complete datasets were obtained from 384 patients with PD who were either past or present driving license holders. Fifty-seven patients had caused at least one MVA in the last 5 years before the survey. Logistic regression analyses revealed that ergot-dopamine agonist (DA) use and excessive daytime sleepiness (Epworth Sleepiness Scale score ≥ 10) were the best predictors of MVAs. Patients having caused non-sleep-related MVAs had significantly longer disease durations, more frequent ergot-DA use, and higher cognition and communication subscores on the Parkinson's Disease Questionnaire-39 than those without non-sleep-related MVAs (P < .05). The Epworth Sleepiness Scale scores of PD patients with sleep-related MVAs were significantly higher than those of patients without sleep-related MVAs (P < .01).

CONCLUSIONS

Excessive daytime sleepiness and ergot-DA use may be important predictive risk factors for MVAs in PD. Daytime sleepiness appears to be related to sleep-related MVAs in PD, whereas disease progression and ergot-DA use may contribute to non-sleep-related MVAs.

Diffusion-weighted whole-body imaging with background body signal suppression/T2 image fusion for the diagnosis of colorectal polyp and cancer

Diffusion-weighted whole-body imaging with background body signal suppression/T2 image fusion (DWIBS/T2) is useful for the diagnosis of cancer as it presents a clear contrast between cancerous and non-cancerous tissue. The present study investigated the limitations and advantages of DWIBS/T2 with regards to the diagnosis of colorectal polyp (CP) or cancer (CRC). The current study included patients diagnosed with CP or CRC following colonoscopy, who were subjected to DWIBS/T2 between July 2012 and March 2015. Patient records were analyzed retrospectively. Patients were subjected to DWIBS/T2 when they presented with abdominal cancers or inflammation. Colonoscopy was performed as part of screening, or if patients had suspected colon cancer or inflammatory bowel disease. A total of 8 male and 7 female patients were enrolled in the present study. All patients, with the exception of one who had been diagnosed with CRC following colonoscopy, had positive results and all patients diagnosed with CP following a colonoscopy, with the exception of one, had negative results on DWIBS/T2. Thus, CRC was detected by DWIBS/T2, while CP was not (P=0.0028). The diameter of CRC lesions was significantly larger than that of CP (P<0.0001) and that of lesions positive on DWIBS/T2 was significantly larger than that of negative lesions (P=0.0004). The depth of invasion tended to be greater for lesions positive on DWIBS/T2 compared with that of negative ones. This indicated that DWIBS/T2 may be suitable for the detection of CRC but not for detection of CP. The results of DWIBS/T2 may also be affected by lesion diameter and depth of invasion.

Tuberculous Fasciitis in Polymyositis: A Rare Case of Extrapulmonary Tuberculosis

A 71-year-old woman with polymyositis presenting with left thigh pain and an intermittent fever was admitted to Osaka Rosai Hospital. We initially diagnosed that her pain and fever were caused by a soft tissue infection because her polymyositis was controlled. She did not respond to various antibiotic therapies. Chest computed tomography demonstrated miliary tuberculosis (TB). Ziehl-Neelsen staining of liver biopsy specimens revealed epithelioid cell granuloma and acid-fast bacilli. Therefore, we finally diagnosed the lesion as TB fasciitis that improved with anti-TB drug therapy. The atypical presentation of TB fasciitis demonstrates the clinical importance of eliminating TB infections in immunocompromised hosts.

[Effectiveness of a practical protocol for the prevention of contrast-induced nephropathy: improved prevention of contrast-induced nephropathy]

BACKGROUND

In Japan, "Guidelines for iodinated contrast in a patient with chronic kidney disease (CKD) 2012" was published, but preventive protocols for specific contrast-induced nephropathy (CIN) have not been specified. Therefore, we developed a CIN preventive protocol, and validated its operation and renal protective effect.

METHODS

In a retrospective cohort study, we determined eGFR within 3 months before contrast-enhanced computed tomography (CECT). We evaluated CKD stage 3b - 4 adult patients (eGFR 15 - 45 mL/min/1.73m2) who underwent CECT. We observed changes in renal function over 9 months and compared the changes between the pre-protocol group, which received CIN preventive measures from clinicians, and the post-protocol group, which received 500 mL 0.9% saline intravenously over 4 hours or drank 2,000 mL water over 36 hours.

RESULTS

The numbers of CT and CECT patients after validation of the protocol were 5,450 and 2,037, respectively. Among the CECT patients, 310 (15.2%) and 77(3.8%)had eGFRs < 60 and 45 mL/min/1.73 m2, respectively. Among the CECT patients whose eGFRs were < 60 mL/min/1.73 m2, 74.5% were 70 years or older. Tumor scanning accounted for 77% of all CECT cases. The number of CECT patients after 3 months did not significantly differ between the groups (2,189 vs 2,037). The percentage of patients with CKD stage G3b - 4 showed no significant differences (3.3% vs 3.7%, p = 0.89). The proportion of patients whose eGFR did not deteriorate at 3, 6 and 9 months was significantly higher in the post-protocol group than in the pre-protocol group (p < 0.001), and the protocol was the only independently-significant predictor.

CONCLUSIONS

Our protocol prevented CIN and provided a renal protective effect without reducing the number of CECT patients.

High cell density suspension culture of mammalian anchorage independent cells: Oxygen transfer by gas sparging and defoaming with a hydrophobic net

Gas sparging directly into the culture-broth is not done in cell culture, except when the gas flow rate is very small, because much foaming occurs. During screening of defoaming methods, foam was observed to be broken up effectively when it made contact with a net fabricated from hydrophobic materials. Providing a highly efficient oxygen supply to suspension culture was tried using the new defoaming method. In a 5 l reactor equipped with the foam-eliminating net fabricated with polysiloxane, oxygen was transferred at 21 mmole/l.h equivalent to a consumption rate of 1 X 10(8) cells/ml, even at a low oxygen gas flow rate of 0.1 cm/s corresponding to a fourth of the gas flow rate when foam leaked through the net. Perfusion culture of rat ascites hepatoma cell JTC-1 was successfully carried out in the 5 l scale culture system with the net and a hydrophobic membrane for cell filtration. The viable cell concentration reached 2.7 X 10(7) cells/ml after twenty-seven days, in spite of the nutrient-deficient condition of the lower medium exchange rate, that is, a working volume a day, and viability was maintained at more than 90%. In a 1.21 scale culture of mouse-mouse hybridoma cell STK-1, viable cell concentration reached 4 X 10(7) cells/ml. These results showed that oxygen transfer by gas sparging with defoaming was useful for high density suspension culture. A foam-breaking mechanism was proposed.