Association between oral corticosteroid starting dose and the incidence of pneumonia in Japanese patients with ulcerative colitis: a nation-wide claims database study

Background/Aims

A previous study demonstrated that half of patients started oral corticosteroids (OCS) for ulcerative colitis (UC) exacerbations at lower doses than recommended by Japanese treatment guidelines (initial OCS prednisolone equivalent dose, 30-40 mg). This may relate to physician's concern about infection, especially pneumonia including Pneumocystis jirovecii pneumonia (PJP), from high OCS doses. We assessed whether pneumonia incidence is increased with guideline-recommended OCS initial doses.

Methods

This retrospective cohort study used the Japan Medical Data Center claims database (2012-2021). The whole cohort consisted of all UC patients who started OCS during the study period meeting the inclusion and exclusion criteria. The matched cohort was created by propensity score matching; the lower (initial OCS dose < 30 mg), guideline-recommended (30-40 mg), and higher groups ( > 40 mg) in a 2:2:1 ratio. Pneumonia incidence in the primary analysis was evaluated in the matched cohort. A Poisson regression model determined pneumonia-related risk factors in the whole cohort.

Results

After screening, 3,349 patients comprised the whole cohort; 1,775 patients comprised the matched cohort (lower dose, n = 710; guideline-recommended dose, n = 710; higher dose, n = 355). The incidence of any pneumonia was low; no differences were observed in incidence rates across these dose subgroups. In total, 3 PJP cases were found in the whole cohort, but not detected in the matched cohort. Several risk factors for any pneumonia were identified, including age, higher comorbidities index, treatment in large facility and hospitalization.

Conclusions

The incidence of pneumonia, including PJP, in UC patients was low across initial OCS dose treatment subgroups.

Predictors of lower limb fractures in general Japanese: NIPPON DATA90

Objective

This study aimed to investigate the incidence rates and predictors of lower limb fractures in a general Japanese population.

Methods

NIPPON DATA is a nationwide, long-term, prospective cohort study of individuals who participated in the National Cardiovascular Survey Japan and the National Nutrition Survey in 1990. Overall, 3,134 individuals (1,827 women, 1,307 men) who participated in follow-up assessments in 1995, 2000, and/or 2006 were included in the present analysis. The outcomes of this study were lower limb fractures (including proximal femur fractures).

Results

The mean age at baseline was 63.8 years in women and 63.1 years in men. The average body mass index (BMI) was 23.3 kg/m² in women and 22.9 kg/m² in men. During a mean follow-up of 12.1 years, 271 total lower limb fractures were observed. In women, older age, lower BMI, and less intake of vegetables were associated with increased risks of proximal femur fractures. With regard to the outcome of total lower limb fractures, less intake of vegetables and regular exercise were significant predictors in women. Calcium intake was not significantly associated with proximal femur or total lower limb fractures. There were no significant predictors of proximal femur or total lower limb fractures in men, except for age.

Conclusions

Aging was a significant risk factor for proximal femur and total lower limb fractures in both men and women. With regard to modifiable risk factors, low BMI and low intake of vegetables were associated with increased risks of proximal femur and/or total lower limb fractures in the general population of Japanese women.

Conversations and Reactions Around Severe Hypoglycemia (CRASH): Japan Results From a Global Survey of People with T1DM or Insulin-Treated T2DM and Caregivers

AIMS

The CRASH study examined severe hypoglycemia (SH) experiences among people with diabetes (PWD) and caregivers across eight countries. Here we report findings from the Japan cohort, with references to data from the United Kingdom (UK) cohort.

MATERIALS AND METHODS

Adults with type 1 (T1DM) or insulin-treated type 2 diabetes mellitus (T2DM) and caregivers (not necessarily related) were recruited from online patient panels. Participants who had experienced at least one SH event in the past 3 years were eligible for study inclusion. Participants completed an online survey regarding their experience with SH, its treatment, and actions during and after an event.

RESULTS

Of the 9367 PWD and caregivers from the online patient panels, 8475 participants were ineligible and a total of 53 Japanese participants (35 T1DM, 9 T2DM, 9 caregivers) completed the survey. Most SH incidents occurred at home and were unattended by a healthcare provider. For T1DM, 29% of Japan PWD and 13% of the UK PWD called an ambulance during an SH event; of these, 90% (Japan) and 50% (UK) were transported to hospital. Glucagon use was low (3% Japan and 10% UK for T1DM). Japanese respondents reported emotional impacts of SH, including feeling scared (86% T1DM, 56% T2DM), unprepared (63% T1DM, 78% T2DM), and helpless (60% T1DM, 33% T2DM). Despite the emotional burden, most PWD did not immediately discuss their SH event with a healthcare provider, with the majority (75% T1DM, 71% T2DM) waiting until their next doctor's appointment.

CONCLUSION

Conversations around SH between healthcare providers and PWD appear to be insufficient in Japan. An emotional burden of SH was reported by PWD and caregivers. Education regarding the prevention of SH and available treatment options may reduce SH events and improve treatment preparation, while alleviating PWD concerns.

Validation of Self-Monitoring Devices Supporting Sodium Intake Reduction: An Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers

INTRODUCTION

Although several approaches for approximating daily Na intake and the Na/K ratio using casual urine are available, the most useful method remains unclear during daily practice and at home.

METHODS

Twenty-seven participants measured their casual urinary Na/K ratio repeatedly using a Na/K ratio monitor and also measured overnight urine once daily using a monitoring device which delivers on-site feedback to estimate their salt intake under unrestricted, low-salt (LS) (6 g/day), and high-salt (HS) (12 g/day) diets.

RESULTS

The monitoring method utilizing overnight urine to estimate daily Na remained insensitive, resulting in significant overestimation during the LS diet and underestimation during the HS diet periods; estimated salt intake during the LS and HS diet periods plateaued at 7-8 g/day and 9-10 g/day within 3 day; mean estimated salt intake was 11.3 g/day, 7.9 g/day, and 9.8 g/day on the last day of the unrestricted, LS, and HS diets; the coefficient of variation (CV) of the estimated Na intake was 0.23 and 0.17 in the latter half of the low- and high-salt diet periods, respectively. The mean urinary Na/K molar ratio was 5.6, 2.5, and 5.3 on the last day of the unrestricted, LS, and HS diets; the CV of the daily mean Na/K ratio was 0.41 and 0.36 in the latter half of the LS and HS diet periods, respectively. The urinary Na/K ratio during the LS and HS diet periods plateaued within 2 days. The monitoring method based on the daily mean of the casual urinary Na/K ratio reflected the actual change in Na intake, and the estimated value tracked the actual changes in salt intake with smaller difference than the overnight urine estimates when using the estimation coefficient set at 2; estimated salt intake during the LS and HS diet periods plateaued at 5-6 g/day and 10-12 g/day within 2-3 day; mean estimated salt intake was 11.0 g/day, 5.7 g/day, and 10.7 g/day on the last day of the unrestricted, LS, and HS diets, respectively.

DISCUSSION/CONCLUSION

Estimates of daily Na intake derived from overnight urine may remain insensitive during dietary interventions. The urinary Na/K ratio reflects the actual change in Na intake during dietary modification and may serve as a practical marker, particularly during short-term interventions. Conversion from the urinary Na/K ratio to estimated salt intake may be useful, if the coefficient was set appropriate by further investigations.

Urinary sodium/potassium ratio as a screening tool for hyperaldosteronism in men with hypertension

Among individuals with hypertension, the prevalence of secondary hypertension has been reported to be ≈10%. More than half of individuals with secondary hypertension have associated hyperaldosteronism. However, given the current clinical environment, these patients often remain undiagnosed. We hypothesized that the urinary sodium/potassium ratio (Na/K) could be used as a simple, low-cost method of screening for hyperaldosteronism among individuals with hypertension in primary care and health examination settings. We recruited hypertensive individuals aged 30-69 years old who were not taking any antihypertensive medications from among participants in health examinations. Urinary Na and K were measured using second morning urine samples, and the plasma aldosterone concentration (PAC) was also measured. We evaluated the association of the second morning urine Na/K ratio (SMU Na/K) with a high PAC, defined as ≥90th percentile (24.3 ng/dL), using receiver operating characteristic (ROC) curves. Overall, 160 participants (108 men and 52 women) with a mean age of 54.3 years were eligible for this study. The area under the ROC curve for the relationship between SMU Na/K and high PAC was 0.77 (95% confidence interval [CI]: 0.59-0.95) in men and 0.64 (95% CI: 0.36-0.93) in women. In men, SMU Na/K values <1.0 could detect hyperaldosteronism with a sensitivity of 45.5%, a specificity of 97.9%, a positive predictive value of 71.4%, and a negative predictive value of 94.1%. The use of the urinary Na/K ratio may be appropriate as a method of screening for hyperaldosteronism in hypertensive men.

Urinary sodium-to-potassium ratio and intake of sodium and potassium among men and women from multiethnic general populations: the INTERSALT Study

The Na/K ratio may be more strongly related to blood pressure and cardiovascular disease than sodium or potassium. The casual urine Na/K ratio can provide prompt on-site feedback, and with repeated measurements, may provide useful individual estimates of the 24-h ratio. The World Health Organization has published guidelines for sodium and potassium intake, but no generally accepted guideline prevails for the Na/K ratio. We used standardized data on 24 h and casual urinary electrolyte excretion obtained from the INTERSALT Study for 10,065 individuals aged 20-59 years from 32 countries (52 populations). Associations between the casual urinary Na/K ratio and the 24-h sodium and potassium excretion of individuals were assessed by correlation and stratification analyses. The mean 24-h sodium and potassium excretions were 156.0 mmol/24 h and 55.2 mmol/24 h, respectively; the mean 24-h urinary Na/K molar ratio was 3.24. Pearson's correlation coefficients (r) for the casual urinary Na/K ratio with 24-h sodium and potassium excretions were 0.42 and -0.34, respectively, and these were 0.57 and -0.48 for the 24-h ratio. The urinary Na/K ratio predicted a 24-h urine Na excretion of <85 mmol/day (the WHO recommended guidelines) with a sensitivity of 99.7% and 94.0%, specificity of 39.5% and 48.0%, and positive predictive value of 96.3% and 61.1% at the cutoff point of 1 in 24 h and casual urine Na/K ratios, respectively. A urinary Na/K molar ratio <1 may be a useful indicator for adherence to the WHO recommended levels of sodium and, to a lesser extent, the potassium intake across different populations; however, cutoff points for Na/K ratio may be tuned for localization.

The relationship between repeated measurement of casual and 24-h urinary sodium-to-potassium ratio in patients with chronic kidney disease

This study aimed to clarify the relationship between repeated measurements of casual (spot) and 24-h urinary sodium-to-potassium (Na/K) ratios in patients with chronic kidney disease (CKD). A total of 61 inpatients with CKD, 31 in stage 1-3 (eGFR [estimated glomerular filtration rate] ≥ 30 ml/min/1.73 m²) and 30 in stage 4-5 (eGFR < 30 ml/min/1.73 m²), aged 20-85 consuming a low-sodium diet (NaCl [sodium chloride] 6 g/day) were recruited. Urinary Na, K, and Na/K ratios were measured in both casual urine samples and 2-day, 24 h urine samples, and then analyzed by correlation and Bland-Altman analyses. Mean 24-h urine Na/K ratio was higher in participants in stage 4-5 (5.1) than in participants in stage 1-3 (4.1) CKD. Casual urine Na/K ratio was strongly correlated with 2-day, 24-h urine Na/K ratio by sampling 4 casual urine specimens every morning and evening in participants in stage 1-3 (r = 0.69-0.78), but not in stage 4-5 (r = 0.12-0.19). The bias for mean Na/K ratio between 2-day, 24-h urine, and the 4 casual urine sampling ranged from -0.86 to 0.16 in participants in stage 1-3, and the quality of agreement for the mean of this casual urine sampling was similar to that of sampling 8 casual urine samples for estimating 2-day, 24-h values. Methods using repeated casual urine Na/K ratios may provide a reasonable estimation of 24-h urine Na/K ratio in normotensive and hypertensive as well as individuals with stage 1-3, but not stage 4-5 CKD.

Seasonal variation in home blood pressure: findings from nationwide web-based monitoring in Japan

OBJECTIVES

Our aim was to assess seasonal variation in home blood pressure (BP) among free-living nationwide participants using home BP values accumulated from a web-based healthcare platform established in Japan.

SETTINGS

An observational study. OMRON Healthcare Co., Ltd. has been developing web-based personal healthcare record systems in Japan since November 2010; over two million voluntary participants had joined this platform in September 2015. Nationwide home BP measurements made by oscillometric-type electronic sphygmomanometers from over 110 000 voluntary participants have been transmitted to the system from devices.

PARTICIPANTS

Seasonal variation in home BP was evaluated among 64 536 (51 335 men, 13 201 women; mean age 52.9 years) free-living nationwide users for whom data were automatically and simultaneously transmitted to the system from devices.

PRIMARY OUTCOME MEASURES

Mean monthly and weekly home BP.

RESULTS

In multiple regression analysis, the relationship between BP and temperature was a significant inverse association, independent of age, gender and geological locations. Highest and lowest BP was observed in December and July, respectively. Substantial seasonal differences in the mean values of morning and evening home systolic BP between summer and winter were 6.2 mmHg and 5.5 mmHg in men, and 7.3 mmHg and 6.5 mmHg in women. Seasonal variation was a little greater in older (7.3 mmHg in men, 8.7 mmHg in women) than in younger individuals (5.8 mmHg in men, 6.5 mmHg in women). BP from February to July was approximately 1.5 mmHg lower than the value from August to December.

CONCLUSIONS

A web-based healthcare platform has enabled easier monitoring of population-wide BP. Tighter BP control is necessary in winter than in summer, and especially in a colder climate toward winter than toward summer. New technologies using web-based self-monitoring systems for health-related indexes are expected to initiate a new phase of cardiovascular disease prevention and public health promotion.

Effectiveness of a Self-monitoring Device for Urinary Sodium-to-Potassium Ratio on Dietary Improvement in Free-Living Adults: a Randomized Controlled Trial

BACKGROUND

Reducing the urinary sodium-to-potassium ratio is important for reducing both blood pressure and risk of cardiovascular disease. Among free-living Japanese individuals, we carried out a randomized trial to clarify the effect of lifestyle modification for lowering urinary sodium-to-potassium ratio using a self-monitoring device.

METHODS

This was an open, prospective, parallel randomized, controlled trial. Ninety-two individuals were recruited from Japanese volunteers. Participants were randomly allocated into intervention and control groups. A month-long dietary intervention on self-monitoring urinary sodium-to-potassium ratio was carried out using monitors (HEU-001F, OMRON Healthcare Co., Ltd., Kyoto, Japan). All participants had brief dietary education and received a leaflet as usual care. Monitors were handed out to the intervention group, but not to the control group. The intervention group was asked to measure at least one spot urine sodium-to-potassium ratio daily, and advised to lower their sodium-to-potassium ratio toward the target of less than 1. Outcomes included changes in 24-hour urinary sodium-to-potassium ratio, sodium excretion, potassium excretion, blood pressure, and body weight in both groups.

RESULTS

Mean measurement frequency of monitoring was 2.8 times/day during the intervention. Changes in urinary sodium-to-potassium ratio were -0.55 in the intervention group and -0.06 in the control group (P = 0.088); respective sodium excretion changes were -18.5 mmol/24 hours and -8.7 mmol/24 hours (P = 0.528); and corresponding potassium excretion was 2.6 mmol/24 hours and -1.5 mmol/24 hours (P = 0.300). No significant reductions were observed in either blood pressure or body weight after the intervention.

CONCLUSIONS

Providing the device to self-monitor a sodium-to-potassium ratio did not achieve the targeted reduction of the ratio in "pure self-management" settings, indicating further needs to study an effective method to enhance the synergetic effect of dietary programs and self-monitoring practice to achieve the reduction. However, we cannot deny the possibility of reducing sodium-to-potassium ratio using a self-monitoring device.

Estimating 24-h urinary sodium/potassium ratio from casual ('spot') urinary sodium/potassium ratio: the INTERSALT Study

Background

Association between casual and 24-h urinary sodium-to-potassium (Na/K) ratio is well recognized, although it has not been validated in diverse demographic groups. Our aim was to assess utility across and within populations of casual urine to estimate 24-h urinary Na/K ratio using data from the INTERSALT Study.

Methods

The INTERSALT Study collected cross-sectional standardized data on casual urinary sodium and potassium and also on timed 24-h urinary sodium and potassium for 10 065 individuals from 52 population samples in 32 countries (1985-87). Pearson correlation coefficients and agreement were computed for Na/K ratio of casual urine against 24-h urinary Na/K ratio both at population and individual levels.

Results

Pearson correlation coefficients relating means of 24-h urine and casual urine Na/K ratio were r = 0.96 and r = 0.69 in analyses across populations and individuals, respectively. Correlations of casual urine Na/creatinine and K/creatinine ratios with 24-h urinary Na and K excretion, respectively, were lower than correlation of casual and 24-h urinary Na/K ratio in analyses across populations and individuals. The bias estimate with the Bland-Altman method, defined as the difference between Na/K ratio of 24-h urine and casual urine, was approximately 0.4 across both populations and individuals. Spread around, the mean bias was higher for individuals than populations.

Conclusion

With appropriate bias correction, casual urine Na/K ratio may be a useful, low-burden alternative method to 24-h urine for estimation of population urinary Na/K ratio. It may also be applicable for assessment of the urinary Na/K ratio of individuals, with use of repeated measurements to reduce measurement error and increase precision.

Abstract P333: Repeated Measurementof Casual Urine Na/K Ratio May Provide Useful Information to Screen Early Stage Chronic Kidney Disease Patients With Higher Sodium and Lower Potassium Intake

Objective: Lowering sodium-to-potassium ratio has been reported to benefit people for hypertension prevention and control in epidemiological studies. Four to seven repeated measurements of casual urine sodium-to-potassium ratio is known to provide high correlation and good agreement quality with less bias to estimate 7-day 24-hour urinary Na/K ratio in normotensive and hypertensive individuals. However, little is known about urinary Na/K ratio in patients with chronic kidney disease (CKD). The aim of this study was to clarify the relationship of the repeated measurement of casual and 24-hour urinary sodium-to-potassium ratio in patients with CKD.

Design and Method: A total of 61 inpatients with CKD, 31 in stage 1-3 (eGFR ≥ 30 ml/min/1.73m 2 ) and 30 in stage 4-5 (eGFR < 30 ml/min/1.73m 2 ), aged 20 to 85 under low-sodium diet (NaCl 6 g/day) were recruited in Okayama University hospital. Sodium-to-potassium ratio in casual urine at 4 points/day (first void after rising, each urine after breakfast, lunch or dinner) for 2 days and 2-day 24-hr urine at the same day were measured. Correlation and the quality of agreement by Bland and Altman between casual urine and 24-hour urine samples were analyzed.

Results: Mean 24-hour Na and K excretion was lower in participants in stage 4-5 (Na: 87.5 mmol/24h, K: 18.8 mmol/24h) than in participants in stage 1-3 (Na: 99.0 mmol/24h, K: 26.1 mmol/24h), whereas mean 24-hour urine Na/K ratio was higher in participants in stage 4-5 (5.1) than in participants in stage 1-3 (4.1). Casual urine Na/K ratio was strongly correlated with 2-day 24-hour urinary Na/K ratio by sampling 2 casual urine specimens per day for 2 days in participants in stage 1-3 (r = 0.69-0.78), but not in stage 4-5 (r = 0.12-0.19). The bias for mean Na/K ratio between 2-day 24-hour urine and sampling 2 casual urine per day for 2 days in participants in stage 1-3 ranged from -0.86 to 0.16, and the quality of agreement for the mean of this casual urine sampling was similar to that of all 8 points of casual urine samples for estimating 2-day 24-hour values.

Conclusion: Repeated casual urine Na/K ratio measurement may provide good estimate of 24-hour urine Na/K ratio, in stage 1-3 CKD patients as well as normotensive and hypertensive people; however, not in stage 4-5 CKD patients.

Urinary Sodium-to-Potassium Ratio Tracks the Changes in Salt Intake during an Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers

The Na/K ratio is considered to be a useful index, the monitoring of which allows an effective Na reduction and K increase, because practical methods (self-monitoring devices and reliable individual estimates from spot urine) are available for assessing these levels in individuals. An intervention trial for lowering the Na/K ratio has demonstrated that a reduction of the Na/K ratio mainly involved Na reduction, with only a small change in K. The present study aimed to clarify the relationship between dietary Na intake and the urinary Na/K molar ratio, using standardized low- and high-salt diets, with an equal dietary K intake, to determine the corresponding Na/K ratio. Fourteen healthy young adult volunteers ingested low-salt (3 g salt per day) and high-salt (20 g salt per day) meals for seven days each. Using a portable urinary Na/K meter, participants measured their spot urine at each voiding, and 24-h urine was collected on the last day of each diet period. On the last day of the unrestricted, low-salt, and high-salt diet periods, the group averages of the 24-h urine Na/K ratio were 4.2, 1.0, and 6.9, while the group averages of the daily mean spot urine Na/K ratio were 4.2, 1.1, and 6.6, respectively. The urinary Na/K ratio tracked changes in dietary salt intake, and reached a plateau approximately three days after each change in diet. Frequent monitoring of the spot urine Na/K ratio may help individuals adhere to an appropriate dietary Na intake.

Time to Consider Use of the Sodium-to-Potassium Ratio for Practical Sodium Reduction and Potassium Increase

Pathogenetic studies have demonstrated that the interdependency of sodium and potassium affects blood pressure. Emerging evidences on the sodium-to-potassium ratio show benefits for a reduction in sodium and an increase in potassium compared to sodium and potassium separately. As presently there is no known review, this article examined the practical use of the sodium-to-potassium ratio in daily practice. Epidemiological studies suggest that the urinary sodium-to-potassium ratio may be a superior metric as compared to separate sodium and potassium values for determining the relation to blood pressure and cardiovascular disease risks. Higher correlations and better agreements are seen for the casual urine sodium-to-potassium ratio than for casual urine sodium or potassium alone when compared with the 24-h urine values. Repeated measurements of the casual urine provide reliable estimates of the 7-day 24-h urine value with less bias for the sodium-to-potassium ratio as compared to the common formulas used for estimating the single 24-h urine from the casual urine for sodium and potassium separately. Self-monitoring devices for the urinary sodium-to-potassium ratio measurement makes it possible to provide prompt onsite feedback. Although these devices have been evaluated with a view to support an individual approach for sodium reduction and potassium increase, there has yet to be an accepted recommended guideline for the sodium-to-potassium ratio. This review concludes with a look at the practical use of the sodium-to-potassium ratio for assistance in practical sodium reduction and potassium increase.

Diurnal variation of urinary sodium-to-potassium ratio in free-living Japanese individuals

High sodium-to-potassium ratios are associated with elevated blood pressure levels and an increased risk of cardiovascular diseases. We aimed to determine whether urinary sodium-to-potassium ratios fluctuate diurnally during the day to understand measured values of casual urinary sodium-to-potassium ratios. A total of 13,277 casual urine specimens were collected under free-living conditions from 122 Japanese normotensive and hypertensive individuals. Participants collected all casual urine samples in aliquot tubes, reported urine volumes and the time at each voiding for 10-22 days. Then, specimens were classified into hourly data. Diurnal patterns of urinary sodium-to-potassium ratios and urinary concentrations of sodium and potassium were evaluated. Overall mean values of hourly urinary sodium-to-potassium ratios were highest (4.1-5.0) in the early morning, lower (3.3-3.8) in the daytime and higher (4.0-4.4) toward evening hours. The mean urinary sodium and potassium concentrations were the lowest (90-110 and 24-32 mmol l^-1, respectively) during the early morning and higher (110-140 and 35-43 mmol l^-1, respectively) after mid-morning. Diurnal variability of potassium concentrations was larger than for sodium concentrations. Diurnal variations in urinary sodium-to-potassium ratios were comparable between normotensive and hypertensive individuals, between hypertensive individuals with and without antihypertensive medications, and among age and gender-specific subgroups. Overall mean hourly urinary sodium-to-potassium ratios fluctuated diurnally under free-living conditions and were higher during the morning and evening and lower during the daytime compared with 24-h urinary sodium-to-potassium ratios. Diurnal variation in urinary sodium-to-potassium ratios should be considered to understand actual daily dietary levels and avoid over- and under-estimation in clinical practice.

Four to seven random casual urine specimens are sufficient to estimate 24-h urinary sodium/potassium ratio in individuals with high blood pressure

This study was done to clarify the optimal number and type of casual urine specimens required to estimate urinary sodium/potassium (Na/K) ratio in individuals with high blood pressure. A total of 74 individuals with high blood pressure, 43 treated and 31 untreated, were recruited from the Japanese general population. Urinary sodium, potassium and Na/K ratio were measured in both casual urine samples and 7-day 24-h urine samples and then analyzed by correlation and Bland–Altman analyses. Mean Na/K ratio from random casual urine samples on four or more days strongly correlated with the Na/K ratio of 7-day 24-h urine (r=0.80–0.87), which was similar to the correlation between 1 and 2-day 24-h urine and 7-day 24-h urine (r=0.75–0.89). The agreement quality for Na/K ratio of seven random casual urine for estimating the Na/K ratio of 7-day 24-h urine was good (bias: −0.26, limits of agreements: −1.53–1.01), and it was similar to that of 2-day 24-h urine for estimating 7-day 24-h values (bias: 0.07, limits of agreement: −1.03 to 1.18). Stratified analyses comparing individuals using antihypertensive medication and individuals not using antihypertensive medication showed similar results. Correlations of the means of casual urine sodium or potassium concentrations with 7-day 24-h sodium or potassium excretions were relatively weaker than those for Na/K ratio. The mean Na/K ratio of 4–7 random casual urine specimens on different days provides a good substitute for 1–2-day 24-h urinary Na/K ratio for individuals with high blood pressure.

Abstract 072: Newly Developed Personal Device can Detect Changes and Variations of Urinary Na/K Ratio with Standardized Low- and High-salt Meals in Healthy Volunteers

Background: A low-sodium (Na), high-potassium (K) diet is recommended to suppress blood pressure elevation, but determining the absolute amounts of Na and K in a diet is difficult. A novel portable device was developed to allow easy measurement of urinary Na/K ratio on the spot. In this study, our aims were 1): to observe the changes of urinary Na/K ratio in subjects on low- and high-Na diet and 2): to determine if there are differences in urinary Na/K ratio between subjects with and without salt sensitivity.

Methods: Healthy volunteers (14 subjects) ingested standardized low- (3 g NaCl /day) and high-Na (20 g NaCl/day) meals for 7 days each. Urinary Na/K ratio was measured at each voiding using a prototype device (Omron Healthcare). Collection of blood and 24-hour urine was conducted at the end of each diet period (unrestricted (NS), low-salt (LS), and high-salt (HS)). Those with mean blood pressure difference (LS vs. HS) ≥ 5% were determined as salt-sensitive (SS) and others salt-resistant (SR).

Results: Urinary Na/K ratio reached a plateau approximately 3 days after each change in the Na level of the diet. Urinary Na/K ratio of spot urine correlated well with Na/K ratio of 24-hour urine. Average urinary Na/K ratio was 3.9 ± 1.9 on the last day of NS, 0.8 ± 0.3 on LS, and 6.9 ± 2.1 on HS. The variation of urinary Na/K ratio was small during the LS diet period. The change in urinary Na/K ratio of SS group tended to be slower than that of SR. This device may also be useful in diabetic and proteinuric patients as Na/K ratio was affected minimally by experimental glucose and protein addition.

Conclusion: Using an easy-to-use device, measurements of urinary Na/K ratio keenly reflected the sodium level of the diet.

Six random specimens of daytime casual urine on different days are sufficient to estimate daily sodium/potassium ratio in comparison to 7-day 24-h urine collections

The objective of this study was to determine the optimal number and type of casual (spot) urine specimens required to estimate an individual's urinary sodium/potassium (Na/K) ratio. A total of 48 participants, 25 men and 23 women, aged between 25 and 59 years, was recruited from healthy volunteers. The Na/K ratio in each casual urine and 7-day 24-h urine sample was measured. Correlation analysis and the quality of agreement by the Bland and Altman method between casual urine and 24-h urine were analyzed. The mean Na/K ratio of 7-day 24-h urine was 4.3. The mean Na/K ratio of six random specimens of daytime (collected between 09 and 17 hours) casual urine correlated most strongly with the Na/K ratio of 7-day 24-h urine (r=0.87). The bias for the mean Na/K ratio between 7-day 24-h urine and daytime casual urine was almost negligible (0.03), and the quality of agreement for the mean of the six random, daytime casual urine specimens on different days was similar to that of the 2-day 24-h urine samples for estimating 7-day 24-h values. Our findings show that the mean Na/K ratio of six random daytime casual urine specimens on different days was a good substitute for the 2-day 24-h urine Na/K ratio.

The Role of Plasmapheresis Therapy for Perioperative Management in ABO-Incompatible Adult Living Donor Liver Transplantation

BACKGROUND

Although living donor liver transplantation (LDLT) was established as a treatment for end-stage liver disease in Japan, the indication for LDLT across an ABO-incompatible barrier remains controversial. The purpose of this study was to elucidate the role of plasmapheresis in incompatible LDLT.

METHODS

Eleven adult patients (seven men and four women) who underwent incompatible LDLT were enrolled in this study. Of these three patients had hepatocellular carcinoma, three chronic hepatitis C, one Wilson's disease, one autoimmune hepatitis, one chronic hepatitis B, one hemochromatosis, and one fulminant hepatic failure. The immunosuppressive regimen consisted of tacrolimus, prednisolone, mycophenolate mofetil (or cyclophosphamide), and prostaglandin E1 in all patients. Multiple plasmapheresis was performed perioperatively to reduce the recipient's antibody titers against the donor's blood type.

RESULTS

Plasmapheresis was useful for the reduction of the recipient's antibody titers to x 16 or lower before and after transplantation. There was no difference in transplant outcome between the 11 patients with incompatible blood group and 30 patients with identical or compatible blood groups.

DISCUSSION

Major postoperative complications such as intrahepatic biliary complications and hepatic necrosis may occur in incompatible transplantation. Several investigators suggested that anti-immunoglobulin (Ig) M and anti-IgG antibody titers sustained these complications. The antibody titers must be decreased sufficiently with plasmapheresis. An elevation of anti-ABO titers after transplantation may be a predictive risk factor for increased mortality and morbidity. In order to perform LDLT in a safer manner, plasmapheresis is an indispensable treatment to improve the outcome of ABO-incompatible cases.

Pharmacokinetic differences between morning and evening administration of cyclosporine and tacrolimus therapy

We performed 24-hour monitoring of cyclosporine (NEO) and tacrolimus (TAC) blood concentrations, evaluating pharmacokinetic parameters and characterizing circadian variations. The monitoring was performed in 10 instances on nine patients administered NEO and 12 out of 11 patients administered TAC. All cases were administered equally divided doses of drugs twice daily orally. Blood samples were taken before and 1, 2, 3, 4, 6, and 12 hours after NEO or TAC administration in the morning and evening. The pharmacokinetic parameters were compared between morning and evening administrations of both drugs. AUC0-12, AUC0-4, C(max), C2, and C(max)/C(min) of NEO and TAC were significantly lower during the evening compared with morning administrations. C(min) values were significantly higher in the evening. T(max) of NEO was longer in evening, although there was not a significant difference; T(max) of TAC was significantly longer in the evening. We found that NEO and TAC administrations in the evening resulted in reduced bioavailability and delayed absorption when compared with drug administrations in the morning. It was thought that the difference in bioavailability between morning and evening administrations was smaller with TAC, because TAC shows lower peak levels and a flatter blood concentration curve than NEO. C(min) was higher after evening administration than morning because of delayed absorption, though the bioavailability of both drugs decreased in the evening. These results suggest that we have to appreciate apparently high trough levels.

Successful case of adult ABO-incompatible liver transplantation: beneficial effects of intrahepatic artery infusion therapy: a case report

BACKGROUND

In Japan ABO-incompatible liver transplantation has been done on >100 occasions up to 2003. However, <30% are cases involving adults. The difficultly of ABO-incompatible liver transplantation is associated with the high frequency of humoral rejection and local disseminated intravascular coagulation (DIC), leading to many postoperative complications. We report a successful case of adult ABO-incompatible liver transplantation with the use of an intrahepatic artery infusion.

METHODS

A 36-year-old man with Wilson disease, underwent living donor liver transplantation from an ABO-incompatible donor. The immunosuppressive therapy included multiple perioperative plasmaphereses, splenectomy, and treatment with tacrolimus, methylprednisolone, and cyclophosphamide. The dose and blood level of tacrolimus were the same as in ABO-compatible cases. In addition to these therapies, we administered an intrahepatic arterial infusion with prostaglandin (PG) E1 alone.

RESULTS

After perioperative plasmapheresis and cyclophosphamide, antidonor blood group antibody titers remained undiluted and without vascular complications throughout the postoperative course, but there was a tendency for bleeding that continued for 10 days after transplantation. On postoperative day 10, a reexploration was performed for intraabdominal bleeding. During another operation on postoperative day 59 a biloma was found and drained. The patient has now survived for 120 days after transplantation with normal liver function.

CONCLUSIONS

Beneficial effect of intrahepatic artery infusion with PGE1 seems to be useful in adult ABO-incompatible liver transplantation.

Optimal Dose and Target Trough Level in Cyclosporine and Tacrolimus Conversion in Renal Transplantation as Evaluated by Lymphocyte Drug Sensitivity and Pharmacokinetic Parameters

We evaluated the relative clinical potency of cyclosporine (CyA) and tacrolimus (Tac) using pharmacodynamic and pharmacokinetic parameters of the drug to obtain the most suitable converting dose and target trough level. The relative pharmacodynamic potency was examined by the mean ratio of drug concentrations giving 50% inhibition of blastogenesis of lymphocytes (IC50) in 66 chronic renal failure patients. The relative potency estimated from clinical pharmacokinetic parameters was examined by the mean ratio of each pharmacokinetic parameter value of CyA versus Tac. The pharmacokinetic parameters were estimated by 12-hour monitoring of drug blood concentrations in seven CyA patients and seven Tac patients. The mean IC50 ratio of CyA and Tac (CyA/Tac of IC50) was 25.1. The mean area under the concentration-time curve (AUC) ratio (CyA/Tac of AUC) was 25.5, the mean trough level (C(min)) ratio (CyA/Tac of C(min)) was 13.2, and the mean dose per body weight ratio was 25.2. The relative potency estimated from AUC that is the most reliable pharmacokinetic parameter for the estimation of clinical efficacy of calcineurin inhibitors appeared to agree with the relative pharmacodynamic potency estimated from IC50. The data suggest that TAC 25-fold more potent than CyA, which represents a suitable converting dose ratio, and that target trough level of CyA is about 13-fold greater than Tac based on CyA/Tac of C(min). We conclude that these relative values may be useful to estimate the suitable dose and target trough levels to convert between CyA and Tac.

Evaluation of Appropriate Blood Level in Continuous Intravenous Infusion From Trough Concentrations After Oral Administration Based on Area Under Trough Level in Tacrolimus and Cyclosporine Therapy

The target blood concentrations of tacrolimus (TAC) and cyclosporine (CYA) during continuous intravenous infusion (C(ss)) have been determined based on clinical experience. However, it is desirable that C(ss) should be set so that the AUC after intravenous infusion is equal to the AUC after oral administration (AUC(po)). Accordingly, we performed 12-hour monitoring of blood concentrations to calculate C(ss) from the blood trough levels (C(TL)) on 15 kidney recipients administered TAC and 12 recipients administered CYA (Neoral). We used an area under the trough level (AUTL) as a new pharmacokinetic parameter. The C(ss) was evaluated from C(TL), AUC(po), and AUTL was calculated to be C(ss) = C(TL) x (AUC(po)/AUTL). In addition, AUTL/AUC(po) ratio and blood peak/trough level ratio (C(max)/C(min)) were examined to compare pharmacokinetics of TAC and CYA. The formula for TAC was C(ss) = C(TL) x 1.40 and that for CYA, C(ss) = C(TL) x 2.55. The calculated target C(ss) of TAC was 1.40 times that of C(TL), which was similar to the present clinical C(TL). In contrast, the calculated target C(ss) of CYA was 2.55 times the C(TL), and therefore an extremely high C(ss) was necessary to obtain a sufficient AUC that will be available after oral administration. Consequently, intravenous administration of CYA twice a day was considered to be more appropriate to obtain sufficient CYA pharmacokinetics, rather than a continuous intravenous administration. We conclude that the formula, C(ss) = C(TL) x (AUC(po)/AUTL) was useful to calculate the target blood concentration of calcineurin inhibitors when changing from continuous intravenous infusion to oral administration of these drugs.

In vitro production of myeloperoxidase anti-neutrophil cytoplasmic antibody and establishment of Th1-type T cell lines from peripheral blood lymphocytes of patients

OBJECTIVE

To investigate the pathogenic role of T cells in the development of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis.

METHODS

Peripheral blood lymphocytes (PBL) were isolated from myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) associated vasculitis patients and cultured in medium. The production of MPO-ANCA in the medium of PBL stimulated with Concanavalin-A (Con-A), with or without cyclosporin (CyA), was measured by enzyme-linked immunosorbent assay (ELISA) on MPO coated plates. RNA isolated from PBMC of one patient was used for polymerase chain reaction (PCR) and single stranded conformational polymorphism (SSCP) studies, and MPO-specific T cell lines (TCL) were established by antigen stimulation techniques.

RESULTS

PBL of patients with MPO-ANCA-associated vasculitis produced MPO-ANCA following Con-A stimulation, and this effect was inhibited by treatment with cyclosporin A (CyA) or elimination of CD4 cells. PCR-SSCP showed autoantigen-reactive oligoclonal T-cell accumulation in PBMC of one of these patients. We established MPO-specific TCL which secreted interferon-gamma (IFN-gamma), but not interleukin-4 (IL-4); all TCL were CD4 positive, CD8 negative, and HLA-DR restricted.

CONCLUSIONS

Our results suggest that Th1-type T cells may mediate MPO-ANCA production, and may play a role in the onset of MPO-ANCA vasculitis.

Radial flow bioreactor for the creation of bioartificial liver and kidney

A radial flow bioreactor (RFB) is used for a three-dimensional perfusion culture of hepatocellular carcinoma (HCC) cells and renal cells, to create a bioartificial liver and kidney. The cylindrical reactor is filled with porous cellulose microcarrier. RFB can be characterized as a system in which the medium flows from the periphery toward the center of the reactor, thereby delivering an adequate supply of oxygen and nutrients to cells at the center as well as at the periphery. HCC cells incubated in the RFB system at high density maintained viability for long periods of time. Proximal tubular cells (LLC-PK1) as well as HCC cells, but not human immortalized mesangial cells (HMC) were cultured in the RFB for more than 14 days. The mRNA expression of some enzymes involved in the urea cycle, cytochrome P450s in HCC cells, and the 1-alpha-hydroxylase (CYP27B1) in LLC-PK1 cells was higher than that in monolayer cultures. These results suggest that the RFB system composed of HCC cells or renal cells may be useful for a bioartificial liver and kidney.

Systemic granulomatous arteritis associated with Epstein-Barr virus infection

A 61-year-old woman initially presented with symptoms and findings reminiscent of infectious mononucleosis, and her illness then took a rapidly fatal course. Autopsy revealed widespread granulomatous arteritis, with multinucleated giant cells but without eosinophils and fibrinoid necrosis, affecting small arteries and arterioles and infiltration of haemophagocytic histiocytes into many organs. In situ hybridization with Epstein-Barr virus (EBV)-specific oligonucleotide probes showed positive signals in the infiltrating immune cells and epithelial and endothelial cells of the affected organs. EBV-associated haemophagocytic syndrome (EBV-AHS) with systemic granulomatous arteritis was diagnosed. From the immunophenotypes of the infiltrating immune cells, a possible role of CD4+ T-cells in the pathogenesis of this haemophagocytic syndrome and granulomatous vasculitis was suggested.

[Excellent antiproteinuric effect by LDL apheresis in a case with severe renal dysfunction due to focal segmental glomerulosclerosis]

We report here a 19-year-old man with intractable nephrotic syndrome due to focal glomerulosclerosis (FGS) treated by low-density lipoprotein apheresis (LDL-A). The patient had been receiving several drugs, including steroids, cyclophosphamide, mizoribine and deoxysparguarine, for the past ten years, but the nephrotic syndrome was resistant to these drugs. Although the initial renal biopsy specimen showed minimal change-type lesions, the second biopsy specimen obtained 6 years later revealed typical FGS findings accompanied by lipid deposition (apoB) and macrophage infiltration (CD68) in the involved area. LDL-apheresis was performed ten times per course using a dextran sulfate cellulose column (Liposorba LA-15) as the LDL absorber and polysulfone hollow-fibers (Sulflux) as the plasma separator, processing a total of 3,000 ml of plasma during each apheresis. After treatment the serum levels of LDL and total cholesterol decreased to 50% and 58% of their initial levels, respectively. Immediately after the first course of treatment, the renal dysfunction did not improve, but a decrease in urinary protein was observed (from 43.7 g/day to 8 g/day). Two months later, because urinary protein increased and renal function decreased (Ccr 7 ml/min), a second course of treatment was started. However, his renal dysfunction did not improve and urinary protein did not decrease. In conclusion, in FGS with-progressive renal failure, renal histological findings of positive APO-B, CD68 (macrophage) in sclerotic lesion may be indications of effective LDL-apheresis.

CD28 co-stimulatory signals induce IL-2 receptor expression on antigen-stimulated virgin T cells by an IL-2-independent mechanism

Intravenous sensitization of C57BL/6 (B6) mice with class II H-2-disparate B6-C-H-2bm12(bm12) resting B cells induced anti-bm12 CD4+ T cell tolerance as shown by hyporesponsiveness in the anti-bm12 mixed lymphocyte reaction (MLR). The present study investigated the mechanism(s) of the failure of bm12 B cells to stimulate the proliferation of B6 anti-bm12 CD4+ T cells. While stimulation in vitro to B6 splenic T cells with bm12 antigen-presenting cells (APC) induced IL-2 mRNA expression and IL-2 production, T cells stimulated with bm12 B cells expressed much less IL-2 mRNA and secreted very low but detectable levels of IL-2. Moreover, the T cells stimulated with the bm12 B cells did not proliferate and this was not corrected by the addition of rIL-2 responsiveness. Further, whereas IL-2 receptor (IL-2R) alpha chain expression was significantly induced on B6 T cells stimulated with bm12 APC; stimulation with bm12 B cells did not induce IL-2R expression over background levels. However, virgin T cells stimulated with both bm12 B cells and anti-CD28 mAb proliferated and displayed a dramatic increase in IL-2 production as well as IL-2R expression to levels commensurate with those resulting from bm12 B cells plus anti-CD28 mAb even in the presence of sufficient amounts of anti-IL-2 mAb for neutralizing produced IL-2; while levels of IL-2R were significantly lower compared to those induced in the absence of anti-IL-2 mAb, increased frequencies of IL-2R+ cells were comparable. Conversely, IL-2R was not induced by bm12 B cell stimulation in the presence of IL-2. Moreover, IL-2R expression and proliferation induced by stimulation with bm12 APC was inhibited by CTLA-4-Ig, a soluble recombinant fusion protein capable of blocking the CD28 co-stimulatory signals not only stimulate IL-2 production but also induce IL-2R expression by an IL-2-independent mechanism.