Alterations in urinary ceramides, sphingoid bases, and their phosphates among patients with kidney disease.

Background: To avoid an invasive renal biopsy, noninvasive laboratory testing for the differential diagnosis of kidney diseases is a desirable goal. As sphingolipids are demonstrated to be involved in the pathogenesis of various kidney diseases, we investigated the possible usefulness of the simultaneous measurement of urinary sphingolipids for differentiating kidney diseases. Materials and methods: Residual urine specimens were collected from patients who had been clinically diagnosed with chronic glomerulonephritis (CGN), diabetic mellitus (DM), systemic lupus erythematosus (SLE), and arterial hypertension (AH). The urinary sphingolipids-CERs C16:0, C18:0, C18:1, C20:0, C22:0, and C24:0; sphingosine [Sph]; dihydrosphingosine; sphingosine 1-phosphate [S1P]; and dihydroS1P [dhS1P]-were measured by liquid chromatography-tandem mass spectrometry. Based on the results, machine learning models were constructed to differentiate the various kidney diseases. Results: The urinary S1P was higher in patients with DM than in other participants (P < 0.05), whereas dhS1P was lower in the CGN and AH groups compared with control participants (P < 0.05). Sph and dhSph were higher in patients with CGN, AH, and SLE than in those with control participants (P < 0.05). The urinary CERs were significantly higher in patients with CGN, AH, and SLE than in those with control participants (P < 0.05). As a results of constructing a machine learning model discriminating kidney diseases, the resulting diagnostic accuracy and precision were improved from 94.03% and 66.96% to 96.10% and 78.26% respectively, when the urinary CERs, Sph, dhSph, S1P, dhS1P, and their ratios were added to the models. Conclusion: The urinary CERs, sphingoid bases, and their phosphates show alterations among kidney diseases, suggesting their potential involvement in the development of kidney injury.

Evaluation of the fully automated urine particle analyzer UF-1500.

BACKGROUND AND AIMS: This study primarily assessed the performance of the UF-1500, the novel and compact model of the fully automated urine particle analyzer and evaluated its performance against the existing UF-5000 instrument. MATERIALS AND METHODS: A total of 648 residual urine specimens were randomly collected and examined using both the UF-1500 and UF-5000 instruments as well as manual microscopy. For each parameter, the concordance rates and detection accuracy of the UF-1500 against manual microscopy were compared with the UF-5000. RESULTS: The concordance rates between the UF-1500 and manual microscopy were 75.3%-98.5%. The UF-1500 concordance rates within one group agreement were observed to be >90%, for all parameters except for YLCs. The differences within one group agreement between the UF-1500 and manual microscopy were insignificant, in comparison to the UF-5000, with exceptions noted for ECs and YLCs. The sensitivity and specificity of the UF-1500 for RBCs, WBCs, Squa.ECs, and BACT exceeded 80%, while the positive predictive values of ECs and CASTs were below 70%. CONCLUSION: The UF-1500 exhibited a performance that was comparable to the existing instrument, the UF-5000, and was suitable to be introduced in clinical practice. For the samples with suspected false-positive or false-negative results, a manual microscopic examination is required for accurate testing.

Long-term outcomes of functional single ventricles associated with heterotaxy syndrome†.

OBJECTIVES: The goal of this study was to determine the long-term surgical outcomes of patients with functional single ventricles associated with heterotaxy syndrome, risk factors for mortality and factors associated with Fontan stage completion. METHODS: Overall, 279 patients with a functional single ventricle associated with heterotaxy syndrome who underwent an initial surgical procedure at our institute between 1978 and 2021 were grouped into 4 "eras" based on the surgical year during which the initial procedure was performed: era 1 (1978-1989, n = 71), era 2 (1990-1999, n = 98), era 3 (2000-2009, n = 64) and era 4 (2010-2021, n = 46). Neonatal surgery was more frequent in eras 3 and 4 than in eras 1 and 2. RESULTS: Overall, 228 patients had right atrial isomerism; 120 patients (43.0%) had a total anomalous pulmonary venous connection; and 58 patients (20.8%) underwent an initial procedure as neonates. Overall survival rates at 10, 20 and 30 years after the initial procedure were 47.1%, 40.6% and 36.1%, respectively. Neonatal surgery (P < 0.001), total anomalous pulmonary venous connection repair at the initial procedure (P < 0.001) and early era (P < 0.001) were identified as risk factors for mortality, with the last 2 variables being negatively associated with Fontan stage completion (P < 0.001 for both). CONCLUSIONS: Although era had a favourable effect on survival, total anomalous pulmonary venous connection with intrinsic pulmonary vein obstruction was associated with both mortality and Fontan stage completion. CLINICAL REGISTRATION NUMBER: R19092.

Comparison of the clinical performance of the Atyp.C parameter of the UF-5000 fully automated urine particle analyzer with that of microscopic urine sediment analysis.

a Objectives: Urinalysis is one of the most common laboratory screening tests to detect problems in the renal and urinary system; however, they cannot detect atypical cells (Atyp.Cs). The Sysmex UF-5000, a fully automated urine particle analyzer, can detect Atyp.Cs via its Atyp.C parameter. This study aimed to compare the clinical value of the Atyp.C parameter with that of urine sediment microscopy. b Method: A total of 471 leftover urine samples were submitted to the Department of Clinical Laboratory at the University of Tokyo Hospital for urinalysis by manual sediment microscopy examination and UF-5000 Atyp.C analysis. c Result: Of 471 submitted samples, 117 were positive for Atyp.Cs by urine sediment and 354 samples were negative. The histological subtypes of the Atyp.Cs included 105 cases of suspected urothelial carcinoma cells, 10 suspected squamous carcinoma cells, and 2 of suspected adenocarcinoma cells. The Atyp.C values for the Atyp.C-positive and -negative groups were 2.64 ± 0.69 and 0.38 ± 0.16, respectively. The optimal Atyp.C cutoff value determined by the receiver operating characteristic curve analysis was 0.4/µL. The area under the curve was 0.856, with a sensitivity of 79.5% and specificity of 85.1%. Atyp.C values of the UF-5000 showed high predictive performance for Atyp.C-positive specimens identified by urine sediment microscopy. d Conclusions: This study shows that a combination of UF-5000 analysis and microscopic examination of urine sediment improves Atyp.C detection in urine sediment analysis. These results suggest that Atyp.C measured by UF-5000 could be a useful screening parameter in routine testing of urine samples.

Death, reoperation, and late cardiopulmonary function after truncus repair.

Objective: To identify the late surgical outcomes of truncus arteriosus. Methods: Fifty consecutive patients with truncus arteriosus who underwent surgery between 1978 and 2020 at our institute were enrolled in this retrospective, single institutional cohort study. The primary outcome was death and reoperation. The secondary outcome was late clinical status, including exercise capacity. The peak oxygen uptake was measured by a ramp-like progressive exercise test on a treadmill. Results: Nine patients underwent palliative surgery, which resulted in 2 deaths. Forty-eight patients went on to truncus arteriosus repair, including 17 neonates (35.4%). The median age and body weight at repair were 92.5 days (interquartile range, 10-272 days) and 3.85 kg (interquartile range, 2.9-6.5 kg), respectively. The survival rate at 30 years was 68.5%. Significant truncal valve regurgitation (P = .030) was a risk factor for survival. Survival rates were similar between in the early 25 and late 25 patients (P = .452). The freedom from death or reoperation rate at 15 years was 35.8%. Significant truncal valve regurgitation was a risk factor (P = .001). The mean follow-up period in hospital survivors was 15.4 ± 12 years (maximum, 43 years). The peak oxygen uptake, which was performed in 12 long-term survivors at a median duration from repair of 19.7 years (interquartile range, 16.8-30.9 years), was 70.2% of predicted normal (interquartile range, 64.5%-80.4%). Conclusions: Truncal valve regurgitation was a risk factor for both survival and reoperation, thus improvement of truncal valve surgery is essential for better life prognosis and quality of life. Slightly reduced exercise tolerance was common in long-term survivors.

Comparison of long-term outcomes of atrial switch with Rastelli and physiological repair using left ventricle-to-pulmonary artery conduit for levo-transposition of the great arteries.

OBJECTIVES: The objectives of this study was to compare the long-term outcomes of anatomic repair using atrial switch with the Rastelli procedure versus physiological repair with left ventricle-to-pulmonary artery conduit for patients with levo-transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction. METHODS: Of patients with levo-transposition of the great arteries who underwent biventricular repair between 1978 and 2001, 31 hospital survivors after anatomic repair of atrial switch and the Rastelli (anatomic group) and 14 hospital survivors after physiological repair with left ventricle-to-pulmonary artery conduit (physiological group) were enrolled. Survival rates, reoperation rates, and most recent conditions were compared. RESULTS: The overall survival rate at 20 years was 79.7% (95% CI, 66.4%-95.6%) in the anatomic group and 85.1% (95% CI, 68.0%-100%) in the physiological group (P = .87). The reoperation rate at 10 years was 19.8% (95% CI, 5.6%-34.0%) in the anatomic group and 52.0% (95% CI, 25.0%-79.1%) in the physiological group (P = .067). Only patients in the physiological group underwent systemic tricuspid valve replacement. The anatomic group showed a better cardiac index at catheterization (2.79 ± 0.75 L/min/m2 vs 2.30 ± 0.54 L/min/m2; P = .035), lower serum brain natriuretic peptide (73 ± 86 pg/mL vs 163 ± 171 pg/mL; P = .024), and better maximal oxygen uptake in the treadmill test (64.1 ± 16.5% vs 52.7 ± 17.8% of predicted normal; P = .036), although the period until most recent catheterization, blood inspection, and treadmill testing were earlier in the anatomic group. CONCLUSIONS: Preservation of the left ventricle as the systemic ventricle using anatomic repair contributes to better cardiopulmonary condition compared with physiological repair.

Impact of right ventriculotomy for tetralogy of Fallot repair with a pulmonary valve-sparing procedure.

Objectives: The study objectives were to reconfirm the superiority of the pulmonary valve-sparing procedure versus the transannular patch procedure for repair of tetralogy of Fallot and to evaluate the influence of a right ventriculotomy in the pulmonary valve-sparing procedure. Methods: Between 1978 and 2003, 440 patients (aged <10 years) underwent tetralogy of Fallot repair. Of these patients, 242 (55.0%) underwent the transannular patch procedure, 106 (24.1%) underwent the pulmonary valve-sparing procedure without right ventriculotomy, and 92 (20.9%) underwent the pulmonary valve-sparing procedure with right ventriculotomy. End points focused on adverse events and included all-cause mortality, reoperation, catheter intervention, and symptomatic arrhythmias. To compare the outcomes of pulmonary valve sparing with and without right ventriculotomy, inverse probability weighting was applied to adjust for potential confounding factors. Results: The median follow-up period was 20.3 years (interquartile range, 10.7-27.6). In all cohorts, the pulmonary valve-sparing procedure was the independent factor that reduced adverse events after tetralogy of Fallot repair (hazard ratio, 0.47; 95% confidence interval, 0.23-0.94; P = .033). After weighting, there was no difference in overall survival or event-free survival in the pulmonary valve-sparing with and without right ventriculotomy group. However, the pulmonary valve-sparing with right ventriculotomy group exhibited a larger cardiothoracic ratio (beta: 6.01; 95% confidence interval, 2.36-9.66; P = .001), lower medication-free rate (odds ratio, 0.29; 95% confidence interval, 0.098-0.79; P = .019), and higher New York Heart Association functional classification (odds ratio, 2.99; 95% confidence interval, 1.36-6.80; P = .007) at the latest follow-up. Conclusions: Right ventriculotomy for tetralogy of Fallot repair with pulmonary valve-sparing did not increase major adverse events. However, negative impacts on current status cannot be ignored.

Early Outcomes of Intuity Rapid Deployment Aortic Valve Replacement Compared With Conventional Biological Valves in Japanese Patients.

BACKGROUND: This study aimed to elucidate the short-term surgical outcomes and hemodynamics of the Intuity valve compared to the standard bioprosthesis in Japanese patients.Methods and Results: Among the 307 consecutive patients who underwent aortic valve replacement (AVR) between February 2019 and March 2021, the Intuity valve was implanted in 95 patients (Intuity group) and a conventional stented bioprosthesis was implanted in 193 patients (conventional group). After propensity score matching, there was no significant difference in in-hospital mortality between the Intuity (n=2, 3%) and conventional groups (n=0, P=0.490). Operation, cardiopulmonary bypass, and aortic cross-clamping times were significantly shorter in the Intuity group. Although the effective orifice area index, trans-prosthetic mean pressure gradient, and peak velocity were similar between the 2 groups at 1 week postoperatively, the Intuity group showed a better mean pressure gradient and peak velocity at 1 year postoperatively. Complete atrioventricular block requiring permanent pacemaker implantation developed in 2 patients (3%) in the Intuity group and none in the conventional group (P=0.476). Mild or greater paravalvular leakage was present in 8 patients (13%) in the Intuity group and 2 patients (3%) in the conventional group (P=0.095). CONCLUSIONS: AVR using the Intuity valve in Japanese patients is satisfactory, with a better valve performance and a low incidence of complete atrioventricular block at 1 year postoperatively.

Effect of administration of immunoglobulin preparations on the results of tests for autoantibodies.

OBJECTIVES: We encountered the case in whom the results of autoantibodies tests became transiently positive after high-dose immunoglobulin therapy and investigated the effect of administration of these preparations on autoantibodies tests in subjects with autoimmune diseases who had received high-dose immunoglobulin therapy. METHODS: We measured the autoantibodies in residual serum samples after routine clinical testing from eight subjects with autoimmune diseases who had received high-dose immunoglobulin therapy. We also measured the autoantibodies in available immunoglobulin preparations. RESULTS: Tests for autoantibodies conducted before and after immunoglobulin therapy revealed a positive conversion of the results for anti-Sjogren's syndrome antigen A (SS-A) antibody, anti-glutamic acid decarboxylase (GAD) antibody, anti-thyroglobulin (Tg) antibody, and anti-thyroid peroxidase (TPO) antibody. In five cases in which changes in the antibody titres of anti-SS-A antibody after the high-dose immunoglobulin administration, it was found that the titres decreased by about 50% from 10 to 20 days after and the test result became negative 25- 30 days later. CONCLUSIONS: In patients receiving high-dose immunoglobulin therapy, there appears to be a high likelihood of positive conversion of tests for anti-SS-A antibody, GAD antibody, Tg antibody, and TPO antibody after the treatment, so that cautious interpretation of the results is of importance.

Usefulness of duplex ultrasonography to detect collagen sponge misplacement into the arterial lumen during the use of Angio-Seal: A case report.

A 76-year-old man who had undergone percutaneous coronary intervention suffered intermittent claudication. Duplex ultrasonography revealed superficial femoral artery stenosis with an intraluminal heterogeneous echogenic mass. We suspected that stenosis was caused by the puncture procedure of the Angio-Seal. Open surgery revealed that a collagen sponge that should have been outside the arterial wall was misplaced in the wall with massive granulation, and atherectomy with patchplasty was performed. Vessel deterioration was considered due to several factors, including inappropriate access site, arterial wall calcification, and comorbidities like Behçet's disease. Ultrasonography is a convenient and useful method to evaluate arterial lesions.

Prevalence and clinical characteristics of patients with biologically false-positive reactions with serological syphilis testing in contemporary practice: 10-year experience at a tertiary academic hospital.

OBJECTIVES: Biologically false positive (BFP) reactions are well described in early literature. However, only a few recent reports described the incidence and clinical characteristics of patients with BFP reactions. We reviewed the serological test results of patients tested for syphilis in our hospital in the past decade and described the clinical characteristics of patients with BFP reactions. METHODS: This is a retrospective study of patients tested for syphilis in a tertiary academic hospital. All serological results were retrieved from the clinical laboratory database. We calculated the incidence of BFP reactions. Clinical characteristics and laboratory data of patients with BFP reactions were reviewed manually. RESULTS: Among 94 462 subjects, 588 patients had BFP reactions (0.62%). Most BFP reactions were observed in patients aged over 60 years, with a history of malignancy and autoimmune diseases. Eighty-five per cent of patients had low rapid plasma reagin (RPR) titre (≤1:4), but two patients had extremely high RPR titre (≥1:256). BFP reactions were more likely to persist beyond 6 months among patients with RPR titre of ≥1:8. There was no statistically significant correlation between RPR titre and total protein albumin gap, surrogate of immunoglobulin levels among patients with BFP reactions. CONCLUSION: There was a low incidence of BFP reactions in the last decade. A minority of BFP reactions had high non-treponemal antibody titre and persisted longer than 6 months. In the era of re-emergence of syphilis, this information could help clinicians interpret the results of well-established diagnostic tests for syphilis.

Analysis of vasovagal syncope in the blood collection room in patients undergoing phlebotomy.

Vasovagal syncope (VVS) is well-known to occur in patients undergoing phlebotomy, however, there have been no large-scale studies of the incidence of VVS in the blood collection room. The aim of our present retrospective study was to investigate the conditions of phlebotomy and determine the incidence/factors predisposing to the development of VVS. We investigated 677,956 phlebotomies performed in outpatients in the blood collection room, to explore factors predisposing to the development of VVS. Our analysis revealed an overall incidence of VVS of 0.004% and suggested that use of more than 5 blood collection tubes and a waiting time of more than 15 min were associated with a higher risk of VVS. The odds ratios of these factors were 8.10 (95% CI 3.76-17.50) and 3.69 (95% CI 0.87-15.60), respectively. This is the large-scale study to analyze factors of the development of VVS in the blood collection room, and according to our results, use of a large number of blood collection tubes and a prolonged waiting time for phlebotomy may be risk factors for the development of VVS.

Midstream urine sampling is necessary for accurate measurement of the urinary level of neutrophil gelatinase-associated lipocalin in healthy female subjects.

BACKGROUND: Urinary neutrophil gelatinase-associated lipocalin is an established biomarker of acute kidney injury, however, the levels are affected by the number of white blood cells in the urine. As we suspected the portion of the urinary stream sampled could also have a significant influence on the urinary NGAL levels in female subjects, we investigated the influence of the urine sampling procedure on the urinary NGAL levels. METHODS: We collected 25-mL urinary specimens from each of initial-stream and midstream urinary specimens, including 28 healthy adult female volunteers without kidney diseases or UTI. Then we compared the WBC count, NGAL level, and creatinine level between these specimens. RESULTS: We observed that the urinary NGAL levels were significantly higher in the specimens obtained from initial-stream urinary samples than in midstream specimens, and that they were strongly correlated with the leukocyte esterase activity and WBC count. Moreover, the differences in the urinary NGAL levels between the initial- and midstream urine samples were greater for initial-stream samples with higher leukocyte esterase activities, with a significant difference even for the initial-stream samples with no detectable leukocyte esterase activity. CONCLUSION: Therefore, midstream urine sampling is strongly recommended for accurate measurement of the urinary NGAL levels.

Successful Staged Repair for Truncus Arteriosus With Anomalous Arch Vessels and Left Coronary Artery.

A patient was born with truncus arteriosus type 2, left aortic arch, anomalous origin of arch vessels, left coronary artery from the right common carotid artery, and multiple extracardiac anomalies. Surgery involving translocation of the left coronary artery to the truncal root, division of branch pulmonary arteries from the truncal artery, and right ventricle-to-branch pulmonary arteries conduit placement was performed at the age of four months. Closure of the ventricular septal defect using a one-way fenestrated patch and conduit upsizing was performed successfully when the patient reached four years of age.

Sphingosine 1-phosphate release from platelets during clot formation: close correlation between platelet count and serum sphingosine 1-phosphate concentration.

BACKGROUND: Sphingosine 1-phosphate (Sph-1-P), abundantly stored in platelets and released extracellularly upon activation, plays important roles as an extracellular mediator by interacting with specific cell surface receptors, especially in the area of vascular biology and immunology/hematology. Although the plasma Sph-1-P level is reportedly determined by red blood cells (RBCs), but not platelets, this may not be true in cases where the platelets have been substantially activated. METHODS AND RESULTS: We measured the Sph-1-P and dihydrosphingosine 1-phosphate (DHSph-1-P) levels in serum samples (in which the platelets had been fully activated) from subjects with (n = 21) and without (n = 33) hematological disorders. We found that patients with essential thrombocythemia exhibited higher serum Sph-1-P and DHSph-1-P concentrations. The serum Sph-1-P concentration was closely correlated with the platelet count but was very weakly correlated with the RBC count. Similar results were obtained for DHSph-1-P. The serum Sph-1-P and DHSph-1-P levels were inversely correlated with the level of autotaxin (ATX), a lysophosphatidic acid-producing enzyme. A multiple regression analysis also revealed that the platelet count had the greatest explanatory impact on the serum Sph-1-P level. CONCLUSIONS: Our present results showed close correlations between both the serum Sph-1-P and DHSph-1-P levels and the platelet count (but not the RBC count); these results suggest that high concentrations of these sphingoid base phosphates may be released from platelets and may mediate cross talk between platelet activation and the formation of atherosclerotic lesions.

[Questionnaire survey of the POCT device antsense ROSE for blood glucose analysis on healthcare professionals--evaluation focused on preventive measures against cross-infections].

Considering the possibility of being used for any patients, such a risk-managed medical device is necessary in the perspective of the prevention of hospital infections. Antsense ROSE, a newly developed POCT (Point of Care Testing) diagnostic device for blood glucose analysis, is designed for safety in hospital use. Use of a disposable chip filter for blood sampling prevents cross-infection through device. As to infection control, we carried out a questionnaire survey of healthcare professionals specialists in diabetes to evaluate the feasibility of this device in clinical practice. Despite the infection control system of this device, the survey participants pointed out only a little improvement in infection risk compared with conventional methods. Some were concerned about the cross-infection because blood sampling itself increases the risk of infection, and because it is difficult for examiners to prevent infections completely due to handling blood samples. Systems ensuring safety, such as a fail-safe, are essential for in-hospital use to prevent hospital infections due to the possibility of using a device for several patients, and to ensure the security even for wrong operations. Further investigations, developments and educational campaign will be required for the use of risk managed devices against in-hospital infections.

[Establishment of a pharmacogenomic testing system for the realization of individual pharmacotherapy].

The metabolism of and sensitivity to drugs differ from individual to individual, and one base polymorphism of drug-metabolizing enzymes is known to play an important role in this difference between individuals. The genotyping of drug-metabolizing enzymes prior to drug administration would help to predict individual reactivity to drugs and possible adverse reactions that may occur, which is essential to realize tailor-made therapy for individual patients. In July 2005, the Pharmacogenomics Working Group, composed of members of the Clinical Genomic Medicine Unit, Pharmaceutical Department, Medical Informatics Department, Clinical Laboratory, Gastroenterology, Cardiovascular Medicine, and Department of Neurology, was established in our university hospital in an attempt to introduce such pharmacogenomic testing. The project was approved by the Institutional Research Ethics Committee of the Faculty of Medicine, the University of Tokyo, and, in August 2006, testing for CYP2C19*2 and CYP2C19*3, enzymes involved in the metabolism of proton pump inhibitors, was started. Furthermore, in August 2007, testing for CYP2C9*3, the enzyme involved in the metabolism of Warfarin, and vitamin K epoxidereductase1 (VKORC1) 6484 C>T was started. In the CYP2C19 genotyping, the high incidence of poor metabolizers has been demonstrated; it was speculated that the test could confirm the adverse effects of the drug, i.e., after administration of the drug to patients. Moreover, testing for CYP2C9*3 and VKORC1 6484 C>T was shown to be useful for the safe administration of warfarin. The pharmacogenomic testing system was successfully established in our university hospital, and the Pharmacogenomics Working Group is still active, playing an important role in this project.

[The current status of leukemia genetic testing and the trial of its standardization].

The pathogenic chromosome translocations present in various hematological malignancies result in the formation of fusion genes, which are detected by a reverse transcription-polymerase chain reaction (RT PCR) method. Furthermore, with this method, it is possible to detect minimal residual disease (MRD) sensitively, which is difficult with morphological testing. It has been established that the detection of MRD is important for diagnosis, evaluation of prognosis, and monitoring of leukemia. In particular, quantitative analysis of MRD load transition during the initial phase of treatment is of high prognostic value. At present, however, there is no standard laboratory procedure for leukemia genetic testing. Here, the problems related to external precision management are discussed.

Determination of serum D-lactic and L-lactic acids in normal subjects and diabetic patients by column-switching HPLC with pre-column fluorescence derivatization.

d-Lactic and l-lactic acids were simultaneously determined by means of a column-switching high-performance liquid chromatography (HPLC) with fluorescence detection. As a fluorescence reagent, 4-nitro-7-piperazino-2,1,3-benzoxadiazole (NBD-PZ) was employed for the fluorescence derivatization of lactic acid. The proposed HPLC system adopted both octylsilica (Cadenza CD-C8) and amylose-based chiral columns (CHIRALPAK AD-RH), which proved to give a sufficient enantiomeric separation of the lactic acid derivatives with a separation factor ( alpha) of 1.32 and a resolution ( R(s)) of 1.98. Moreover, the features of the first elution of d-lactic acid peak in the proposed HPLC were convenient for the determination of trace amount of serum d-lactic acid, which is known to increase under diabetes. Intra-day and inter-day accuracies were in the range of 90.5-101.2 and 89.0-100.7%, and the intra-day and inter-day precisions were 0.3-1.2 and 0.4-4.8%, respectively. The proposed method was applied to determine d-lactic and l-lactic acids in human serum of normal subjects and diabetic patients, showing that both d-lactic and l-lactic acid concentrations were significantly increased in the serum of diabetic patients ( n=31) as compared with normal subjects ( n=21). This fact was found for the first time owing to the development of the proposed HPLC method which is able to determine d-lactic and l-lactic acid simultaneously. Finally, serum d-lactic acid concentrations determined by the proposed HPLC method were compared with those from a reported enzymatic assay, and the smaller p value between normal subjects and diabetic patients was shown by the proposed HPLC method.