Current status of liver function tests in Japan.

Inter-laboratory variations in data obtained from surveillance in Japan were studied. The items evaluated were related to liver function and were as follows: total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (gamma-GT), cholinesterase (CHE), lactate dehydrogenase (LD), alkaline phosphatase (ALP) and hepatitis markers. Inter-laboratory coefficients of variations for bilirubin, AST and ALT were acceptable, being less than 10%. but higher variations were found for thle other enzyme assays. Detection of hepatitis markers was acceptable. However. even for parameters with lower inter-laboratory variation, differences in obtained values among different reagents or methods still existed. Thus, standardization will be needed for laboratory data in Japan, and this will contribute to international standardization in laboratory medicine in the future.

Country reports from Japan: external quality assessment scheme in Japan.

Several external quality assessment schemes (EQAS) have been conducted in Japan. Results obtained from nation-scale EQAS reveal the current quality of laboratory testing in each laboratory. The largest nation-scale EQAS in Japan is that conducted by the Japan Medical Association. The numbers of participants and of items evaluated have increased in EQAS by JMA over its history of 32 years. Improvement in inter-laboratory differences has been observed for most items in EQAS in recent decades. In 1998, about 2,500 laboratories from throughout the country participated in this surveillance, and 47 items were evaluated. The coefficient of variations for the group of all participants was less than 5% for about one third of all test items. On the other hand, very high variations over 20% were observed for 6 items. Also, inter-method differences exist for many items, which may be or may not be related to matrix effects. Retrospective evaluation of all EQAS data suggests that there is still room for improvement in inter-laboratory differences.

External quality control results for hormones, tumor markers and CRP testing.

Most hormones, tumor markers, C-reactive protein, and rheumatoid factor (RF) are measured immunologically. Immunological methods based on the antigen-antibody reaction have certain specific problems, including their principle of determination, character of antibodies used, reaction conditions, and others. Free thyroxine (FT4) and thyroid stimulating hormone (TSH), as well as alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), prostate antigen, carcinoantigen 19-9 (CA 19-9), and CA 125 are very commonly measured in the routine medical laboratory. Authentic materials can be obtained for hormones and CRP, and efforts to improve quality control and standardization have been made for years. Results of surveillance for FT4, TSH, and AFP were not poor, but inter-laboratory differences for CEA, CA 19-9, and RF were not insignificant.

Incidence of abnormalities in laboratory tests found in surveillance of adults over 40 years of age.

National health check-up systems have been used for 5 years in Japan for adults who are over 40 years of age. As part of a national project, Osaka prefecture is also conducting a program for health check-up testing and cancer screening for this age group. This surveillance revealed that incidence of obesity, hypertension, cholesterolemia, albuminuria, or abnormal ECG was high. Analysis of surveillance results should contribute to understanding the present status and recent trends in diseases in the aged. With continuation of this surveillance for a number of years, trends in life-style related diseases in Japan should be detectable.

Icsh activities and Asia.

The International Council for Standardization in Haematology (ICSH), an international organization promoting international agreement on hematological testing, is now restructuring to strengthen its activities. In Asia, a diversity of testing methods exists and the resulting testing levels make it difficult to compare test results internationally among Asian countries. Fortunately, the ICSH is considering regionalizing its organization to 5 sub-societies to increase its activity, and we have been able to establish a new society, ICSH-Asia, under the ICSH umbrella.

Size distribution curves of blood cells in thalassemias and hemoglobin H diseases.

Thalassemias and hemoglobinopathies in Thailand have been examined with a blood cell counter based on electroimpedance principle and obtained size distribution curves of red cells and platelets. Among various disorders, beta-thalassemia/hemoglobin E and homozygous hemoglobin Constant Spring showed severe anemia. Their red cell size distribution curve shifted to the left and overlapped with the platelet size distribution curve. Red cell distribution width expressed by coefficient of variation and the degree of the overlapping were stronger in beta-thalassemia/HbE than HbH. Heterozygous beta-thalassemia showed a narrow red cell distribution curve width with small standard deviation and low England's value. Although the overlapping of size distribution curves cause inaccurate red cell count and platelet count, careful observation of the size distribution curves was proved to have high diagnostic value.

Automatic measurement of hemoglobin F in blood obtained from patients with hemoglobin E/E and beta-thalassemia/hemoglobin/E.

This paper presents an automated determination of hemoglobin (Hb) F in Hb E/E disease using Hi-Auto A1c. Blood specimens collected in Bangkok were frozen, and sent to Japan by air mail for the determination. The automatically determined values showed a high correlation with the values obtained by the classical alkali denaturation method. Hb E/E cases showed 4.24 +/- 1.75% of Hb F. On the other hand, Hb, Hct, MCV and MCH in the disease samples were lower than in the controls, but higher than those of beta-thalassemia/HbE disease. From the results it was concluded that Hb E/E could be differentiated from beta-thalassemia/HbE by combination of Hb F value and MCH or Hb in CBC.