Journal of Associated Medical Sciences

Cut-off determination of HLA crossmatching by flow cytometry

Fri, 09 Jan 2026 00:00:00 +0700

Background: Microlymphocytotoxicity test is a gold standard for HLA crossmatching but provides low sensitivity. Emerging flow cytometry crossmatching (FCXM) provides more sensitivity, however, suitable cut-off values for FCXM must still be established for crossmatching result interpretation.

Objectives: This study aimed to determine the appropriate cut-off value for FCXM in kidney transplant patients and donors.

Materials and methods: A total of 30 sample pairs with known HLA typing and known antibody specificity were analyzed. Median channel fluorescence (MCF) and median channel fluorescence shift (MFS) were used to determine cut-off value using three different approaches and % accuracy was determined.

Results: The result showed that the cut-off values from first approach using lowest MCF of positive control and highest MCF of negative control were 1655.99 MCF for T-cells (yielding 100% accuracy) and 43668.06 MCF for B-cells (yielding 36.67% accuracy). The cut-off values from second approach which calculated from standard deviation (SD) of negative control MCF showed SD of T-cells MCF as 203.81 (100% accuracy) and SD for B-cells MCF as 11109.30 (60% accuracy). The cut-off values from third approach derived from the lowest MFS of the expected positive results were 1753.50 for T-cells (100% accuracy) and 593.50 for B-cells (73.33% accuracy).

Conclusion: The cut-off values from the third approach exhibited the highest accuracy. However, FCXM still had false positives and false negatives, underscoring the necessity for continuous refinement and adjustment of cut-off values based on the data accumulated within the laboratory to be used further for routine laboratory practice.

Case report: Two cases of Hb Liuzhou-Yufeng (HBA1:c.334G>T) found in Northern Thailand

Fri, 09 Jan 2026 00:00:00 +0700

Background: Hemoglobin (Hb) Liuzhou-Yufeng is an α-globin variant caused by a heterozygous HBA1 mutation (c.334G>T). However, its clinical significance is not well-defined. Moreover, it is hard to detect using standard capillary electrophoresis (CE) or high-performance liquid chromatography (HPLC) methods and often need molecular techniques like next-generation sequencing (NGS).

Objective: This study aims to describe genotype and hematological features of the first two cases with heterozygosity for Hb Liuzhou-Yufeng found in Northern Thailand and the diagnostic challenges faced.

Materials and methods: Two patients with anemia, a 51-year-old female and a 32-year-old male, underwent hematological evaluation, Hb analysis using CE for case 1 and HPLC for case 2, iron studies, and red cell morphology tests. The dichlorophenolindophenol (DCIP) and osmotic fragility (OF) tests were also conducted. The molecular work-up included multiplex real-time PCR for α-thalassemia deletions, followed by NGS.

Results: Both patients were confirmed by the NGS to carry Hb Liuzhou-Yufeng (ααLY/αα). Their total Hb levels were found within the ranges of mild anemia (10-12 g/dL). However, they had normocytic and normochromic red cells, and the morphology of the red blood cells appeared to be normal. In addition, the Hb analysis by HPLC and CE methods revealed normal peaks and levels of HbA, HbA2, and HbF.

Conclusion: Hb Liuzhou-Yufeng seems clinically harmless but is challenging to detect using conventional methods. This study highlights the importance of NGS in finding rare Hb variants. It improves diagnostic accuracy, genetic counseling, and personalized management of hemoglobinopathy.

Prevalence and risk factors of elevated urinary albumin-to-creatinine ratio in a Thai academic population

Suwatsin Kittikunnathum, Pharisa Nanthawong, Piyawan Bunpo — Fri, 09 Jan 2026 00:00:00 +0700

Background: The urinary albumin–to–creatinine ratio (UACR) is a key marker for early kidney dysfunction. This study assessed UACR levels and their associations with demographic and clinical factors in a Thai university population.

Materials and methods: A cohort of 158 participants (53 males, 105 females) was recruited from Chiang Mai University between January and May 2024. Urinary albumin and creatinine were measured by turbidimetric immunoassay and creatininase method, respectively, and expressed as UACR (mg/gm creatinine). UACR was categorized as normoalbuminuria (<30 mg/gm creatinine), microalbuminuria (30-299 mg/gm creatinine), or clinical albuminuria (≥300 mg/gm creatinine). Data on body mass index (BMI), blood
pressure, fasting blood glucose, physical activity, use of supplements or
medications, and the presence of chronic conditions were also collected.

Results: Most participants (94.3%) had normoalbuminuria, whereas microalbuminuria and clinical albuminuria were observed in 4.4% and 1.3% of participants, respectively. Overall, 71.5% were normotensive and 28.5% hypertensive. Based on BMI, 41.1% had normal weight, 18.4% were overweight, and 34.8% were obese. Nearly half reported no regular exercise, and the majority were non–smokers (98.1%) and non–drinkers (83.5%). Regular supplement or medication use was reported by 57.0%, mainly vitamins/minerals and fish oil. Chronic diseases occurred in 37.3%, with hypercholesterolemia (10.8%) and hypertension (8.9%) being most common. Hypercholesterolemia, hypertension, allergy, type II diabetes, lifestyle factors, and supplement or medication use were not associated with albuminuria (Chisquare, p>0.05), whereas obesity class II, elevated fasting blood glucose (≥126 mg/dL) and systemic lupus erythematosus (SLE) were significantly associated with increased urinary albumin excretion (Chi-square, p<0.05).

Conclusion: Elevated blood glucose, obesity, and SLE were significantly linked to increased UACR, emphasizing the importance of early identification and management of these risk factors to prevent kidney disease progression.