BACKGROUND: The direct/total (d/t) bilirubin ratio can be used to distinguish the causes of jaundice in many patients who have increased levels of direct and indirect bilirubin. However, the reference range of the d/t ratio has not been established, hindering its clinical usefulness. This study assessed the clinical usefulness of the d/t ratio. METHODS: Paired total bilirubin and direct bilirubin tests (N=4,357) of cholestasis, hemolytic anemia, and neonatal jaundice were evaluated. Regression analyses were performed between total bilirubin and direct bilirubin, and between total bilirubin and the d/t ratio for each disease. Theoretical correlation models were established and used to compare the regression analyses data. RESULTS: The theoretical model and regression equation between total bilirubin and direct bilirubin displayed linear correlations for all three cholestatic diseases. The model and regression equation between total bilirubin and the d/t ratio showed reciprocal curve correlations for the cholestatic diseases. When the total bilirubin concentration exceeded approximately 10 mg/dL, the rate of change of the d/t ratio decreased and converged to a constant value between 0.7 and 0.9. CONCLUSIONS: If the total bilirubin concentration exceeds 10 mg/dL, cholestatic diseases can be diagnosed if the d/t ratio is more than 0.7. However, if the total bilirubin concentration is lower than 10 mg/dL, cholestatic diseases should be considered even if the d/t ratio is lower than 0.7. Therefore, use of the d/t ratio with total bilirubin could prove to be valuable in clinical settings.
Anemia, Hemolytic ; Bilirubin* ; Cholestasis ; Humans ; Hyperbilirubinemia ; Infant, Newborn ; Jaundice ; Jaundice, Neonatal ; Models, Theoretical ; Reference Values

BACKGROUND: The 24-hr urine protein excretion test is regarded as a standard for quantitative urinary protein analysis; however, collection of urine over 24 hr is troublesome and errors may occur during the process. We obtained a test index reflecting diluted or concentrated urine by coupling the results of a simple and rapid routine urine analysis and evaluated its usefulness as a marker that quantitatively reflects the 24-hr urine protein excretion. METHODS: The estimated urine protein-osmolality ratio (Pro/Osm) was obtained by two linear regression equations between urine dipstick protein and natural logarithm of the protein concentration, and between urine specific gravity (SG) and urine osmolality (Osm). Sensitivity and specificity of 'estimated urine Pro/Osm' and the widely used urine protein-creatinine ratio were evaluated for their efficiency in diagnosing pathological proteinuria and nephrotic proteinuria based on 24-hr urine protein excretion. RESULTS: Moderate correlations were noted between protein concentration determined by the urine dipstick protein assay and natural logarithm of protein concentration (r=0.86) and between urine SG and urine Osm (r=0.74). The receiver operating characteristics analysis showed that an estimated urine Pro/Osm value of 0.045 had a sensitivity of 91.1% and a specificity of 88.6% for diagnosing pathological proteinuria, and a value of 0.204 had a sensitivity of 100% and a specificity of 80.4% for diagnosing nephrotic proteinuria. CONCLUSIONS: Coupling the results of urine dipstick protein and urine SG determined by the routine analysis will provide additional useful information that will make the screening of renal diseases more cost-effective.
Linear Models ; Mass Screening* ; Osmolar Concentration ; Proteinuria ; ROC Curve ; Sensitivity and Specificity ; Specific Gravity*

BACKGROUND: In vitro levels of complement C3 and C4 proteins are sensitive to storage conditions. To avoid in vitro complement activation when testing is delayed, serum should be frozen at -20degrees C within 2 hr of venipuncture. However, this is impractical in routine laboratory work. Therefore, we investigated alterations in C3 and C4 levels in refrigerated specimens over time and derived formulae to estimate initial levels of complement concentrations in delayed testing. METHODS: Ten fresh specimens were measured for C3 and C4 concentrations and were refrigerated at 4degrees C. We measured C3 and C4 levels in refrigerated samples daily for 4 days using an automated nephelometer (Beckman Coulter Inc., USA). RESULTS: C3 and C4 levels were significantly increased over time in refrigerated specimens (P<0.001, P<0.001, respectively). The increments in C3 and C4 levels were described by the equations: C3 (mg/dL)=3.55x+87.18 (r=0.9909), and C4 (mg/dL)=0.72x+22.3 (r=0.9395), where x=the number of days samples were refrigerated before testing. Increases in C3 and C4 concentrations were described on a percentage basis by the equations: DeltaC3 (%)=4.14x+1.07 (r=0.9903), and DeltaC4 (%)=3.57x+2.48 (r=0.9405). CONCLUSIONS: As the measured C3 and C4 concentrations increased by 3.55 mg/dL (4.1%) and 0.72 mg/dL (3.6%) per day in refrigerated specimens, the levels of C3 and C4 should be adjusted in delayed testing. We proposed that the formulae presented be used to back-calculate initial levels of C3 and C4 concentrations.
Complement Activation ; Complement C3* ; Complement C4 ; Complement System Proteins ; Phlebotomy

BACKGROUND: Diabetes diagnosis can be made using different laboratory tests, including the fasting plasma glucose (FPG) test, 75-g 2-h oral glucose tolerance test (2-h OGTT), and hemoglobin A1c (HbA1c) test; however, these tests have different meanings. This study aimed at comparing patient characteristics based on the diagnosis using each of these 3 tests. METHODS: A total of 750 adults suspected of having diabetes and aged > or =18 years underwent the following tests on the same day: FPG, 2-h OGTT, HbA1c, insulin, general chemistry, and routine urinalysis. The patients were divided into 8 groups based on the combination of positive and negative results of each of the 3 tests, and the characteristics of the patients were compared among groups. RESULTS: In the group that tested positive for all 3 tests, the FPG, 2-h OGTT, HbA1c, homeostasis model assessment for insulin resistance, alanine transaminase, triglyceride, and urine glucose positive values were higher than those of the group that tested positive using the 2-h OGTT and HbA1c test. In the group that tested positive using the 2-h OGTT, blood urea nitrogen was higher than that of the group that tested positive using the HbA1c test. CONCLUSIONS: The characteristics of the patients differed between the tests that yielded positive diagnostic results. This may be related to the fact that the 3 tests indicate different states of glucose metabolism. The results of the 3 tests were significantly different; therefore, it may be more effective to combine the results of the 3 tests to comprehensively describe patient characteristics.
Adult ; Alanine Transaminase ; Blood Glucose ; Blood Urea Nitrogen ; Chemistry ; Diabetes Mellitus ; Diagnosis ; Fasting ; Glucose ; Glucose Tolerance Test ; Homeostasis ; Humans ; Insulin ; Insulin Resistance ; Metabolism ; Triglycerides ; Urinalysis

BACKGROUND: Urine ketone test is commonly used to screen for diabetic ketoacidosis (DKA). Ketonuria also develops in patients with disease conditions other than DKA. However, the prevalence of DKA in patients with ketonuria is not known. We investigated the prevalence of ketonuria and characteristics of patients with ketonuria and estimated the prevalence of DKA among them to study the clinical significance of ketonuria as an indicator of DKA. METHODS: We studied 1,314 adult and 1,027 pediatric patients who underwent urinalysis. The prevalence of ketonuria in the different groups of patients, classified according to the types of their visits to the institution, was investigated, and the relationships between ketonuria and albuminuria, glycosuria, and bilirubinuria were evaluated. RESULTS: The overall prevalence of ketonuria was 9.1%. The prevalences of ketonuria in adult and pediatric patients were 4.3% and 15.2%, respectively. The prevalences of ketonuria were the highest in the adult (9.7%) and pediatric (28%) patients in the group that had visited the emergency department. Among patients with ketonuria, 7% adult and 3.8% pediatric patients showed glycosuria. CONCLUSIONS: This study showed that the prevalence of DKA in patients with ketonuria, defined as the simultaneous presence of ketone bodies and glucose in urine, was only 7%. Therefore, we concluded that ketonuria might be clinically significant as an indicator of acute or severe disease status rather than of DKA.
Adult ; Albuminuria ; Diabetic Ketoacidosis ; Emergencies ; Glucose ; Glycosuria ; Humans ; Ketone Bodies ; Ketosis ; Prevalence ; Urinalysis

Pure red cell aplasia is a bone marrow failure characterized by a progressive normocytic anemia and reticulocytopenia without leucopenia and thrombocytopenia. It is associated with various hematologic diseases. However, pure red cell aplasia with angioimmunoblastic T cell lymphoma has rarely been reported. Here we describe a 43-year-old woman with pure red cell aplasia associated with angioimmunoblastic T-cell lymphoma. She had severe anemia (hemoglobin 6.9 g/dL) and a low reticulocyte count (0.2%). Direct and indirect Coombs' tests were positive. A CT scan of the abdomen revealed marked hepatosplenomegaly and small multiple lymphadenopathies. A bone marrow biopsy revealed focal infiltration of abnormal lymphoid cells and absence of red cell precursors. Splenic biopsy was compatible with angioimmunoblastic T-cell lymphoma. Ultimately, diagnosis of pure red cell aplasia associated with angioimmunoblastic T-cell lymphoma was made. After initiating CHOP therapy, the patient achieved complete remission, which was accompanied, shortly thereafter, by a rise in hemoglobin levels which finally returned to normal.
Abdomen ; Adult ; Anemia ; Biopsy ; Bone Marrow ; Coombs Test ; Female ; Hematologic Diseases ; Hemoglobins ; Humans ; Lymphocytes ; Lymphoma ; Lymphoma, T-Cell ; Red-Cell Aplasia, Pure ; Reticulocyte Count ; T-Lymphocytes ; Thrombocytopenia

Six trials with 3 samples for each trial for external quality assessment of general chemistry and blood gas were performed in 2009. All the control materials were sent in specifically-made boxes at the same time. The response rates were 87.5% in general chemistry and 89.3% in blood gas. The items included sodium, potassium, chloride, BUN, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, AST, ALT, ALP, LD and GGT in general chemistry and pH, pCO2 and pO2 in blood gas. Compared with the previous year (2008), change of the methods of analysis was not remarkable. The peer group coefficient of variation and the VIS scores of general chemistry items were slightly improved.
Bilirubin ; Calcium ; Chemistry, Clinical ; Cholesterol ; Creatinine ; Glucose ; Hydrogen-Ion Concentration ; Korea ; Peer Group ; Phosphorus ; Potassium ; Sodium ; Uric Acid

Six trials with 3 samples for each trial for external quality assessment of general chemistry and blood gas were performed in 2008. All the control materials were sent in specifically-made boxes at the same time. The response rates were 93.5% in general chemistry and 88.1% in blood gas. The items included sodium, potassium, chloride, BUN, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, AST, ALT, ALP, LD and GGT in general chemistry and pH, pCO2 and pO2 in blood gas. Compared with the previous year (2007), change of the methods of analysis and the peer group coefficient of variation was not remarkable and the VIS scores of general chemistry items were slightly improved.
Bilirubin ; Calcium ; Chemistry, Clinical ; Cholesterol ; Creatinine ; Glucose ; Hydrogen-Ion Concentration ; Korea ; Peer Group ; Phosphorus ; Potassium ; Sodium ; Uric Acid

Six trials with 3 samples for each of external quality assessment for general chemistry and blood gas were performed in 2007. All the control materials were sent in specifically-made boxes at the same time. The response rates were 92.0% in general chemistry and 95.5% in blood gas. The items included sodium, potassium, chloride, BUN, glucose, calcium, phosphorus, uric acid, creatinine, bilirubin, total protein, albumin, total cholesterol, triglyceride, AST, ALT, ALP, LD and GGT in general chemistry and pH, pCO2 and pO2 in blood gas. Compared with the previous year (2006), the methods of analysis were slightly changed and the coefficient of variation and VIS scores of general chemistry items were not significantly changed.
Bilirubin ; Calcium ; Chemistry, Clinical ; Cholesterol ; Creatinine ; Glucose ; Hydrogen-Ion Concentration ; Korea ; Phosphorus ; Potassium ; Sodium ; Uric Acid

Hyperphosphatemia is an unusual manifestation in patients with multiple myeloma without a significantly reduced glomerular filtration rate. Serum phosphate may be falsely elevated when a large amount of paraproteins is present in the serum, because ultraviolet light absorbance is elevated with the phosphomolybdate ultraviolet assay, which is most commonly used for serum phosphate measurement. This pseudohyperphosphatemia can be confirmed by deproteinization of the serum of patients. We report a case of multiple myeloma presenting with spurious hyperphosphatemia revealing pseudohyperphosphatemia by deproteinization of serum using sulfosalicylic acid.
Glomerular Filtration Rate ; Humans ; Hyperphosphatemia ; Multiple Myeloma* ; Paraproteinemias ; Paraproteins ; Ultraviolet Rays