Reference intervals for CTX and P1NP in a multi-ethnic Malaysian cohort.

BACKGROUND: Well defined reference intervals are central to the utility of serum C-terminal telopeptide of type 1 collagen (CTX) and N-terminal propeptide of type I procollagen (P1NP), designated as reference markers in osteoporosis, and useful for monitoring therapeutic response in that condition. This study reports the reference intervals for plasma CTX and serum P1NP in a multi-ethnic Malaysian population. METHODS: Ethnic Malay, Chinese or Indian subjects aged 45-90 years old were recruited from Selangor, Malaysia from June 2016 to August 2018. Subjects with known medical conditions (e.g., bone disorders, malnutrition, immobilisation, renal impairment, hormonal disorders) and medications (including regular calcium or vitamin D supplements) that may affect CTX and P1NP were excluded. Additionally, subjects with osteoporosis or fracture on imaging studies were excluded. The blood samples were collected between 8 a.m. and 9 a.m. in fasting state. The CTX and P1NP were measured on Roche e411 platform in batches. RESULTS: The 2.5th-97.5th percentiles reference intervals (and bootstrapped 90%CI) for plasma CTX in men (n = 91) were 132 (94-175) - 775 (667-990) ng/L; in post-menopausal women (n = 132) 152 (134-177) - 1025 (834-1293) ng/L. The serum P1NP reference intervals in men were 23.7 (19.1-26.4) - 83.9 (74.0-105.0) µg/L, and in post-menopausal women, 25.9 (19.5-29.3) - 142.1 (104.7-229.7) µg/L. CONCLUSION: The reference intervals for plasma CTX and serum PINP for older Malaysian men and post-menopausal women are somewhat different to other published studies from the region, emphasising the importance of establishing specific reference intervals for each population.

The relationship between Pattern B lipoprotein profile and low-density lipoprotein cholesterol subfractions with Metabolic Syndrome and Framingham Risk Score in adults at health screening in Malaysia.

INTRODUCTION: Traditional cardiovascular (CV) risk factors are constituents of Metabolic Syndrome (MetS) and Framingham Risk Score (FRS). However, CV risk exists even when these risk parameters are normal and have been attributed to the atherogenic small dense low-density lipoprotein cholesterol (sdLDL). This study aimed to determine the association of Pattern B and LDL subfractions with MetS and FRS among selected Malaysian population. MATERIALS AND METHODS: A cross-sectional study of 380 subjects ≥30 years old at health screening. Sociodemographic factors and clinical characteristics were recorded. Fasting serum lipids, LDL subfractions and plasma glucose were analysed. RESULTS: Being older, Malay with Pattern B independently predicted MetS. Being male, Chinese with Pattern B and increased body mass index (BMI) and diastolic blood pressure (DBP) were more likely to be in the intermediate to high risk FRS group. Common independent biochemical predictors include LDL1 and sdLDL: LDL3 in MetS and non-high-density lipoprotein cholesterol in FRS. CONCLUSION: BMI and DBP may provide incremental prognostic value to FRS risk estimates if included. Considering a significant incidence of Pattern B in low FRS risk subjects (13.4%), routine LDL subfraction analysis could identify these individuals that would be overlooked if their risk were predicted solely based on their FRS only. The non-specific lowering of LDL1 by lipid-lowering therapy based on conventional lipid profile might have a negative effect on several physiological processes. Hence, if LDL subfractions are determined, therapy can be targeted towards sdLDL. Recognising asymptomatic individuals who carry high CV risk is pertinent in primary prevention.

Serum separation abnormality in a multiple myeloma patient.

INTRODUCTION: M-protein secreted by myeloma cells do not only contribute to myeloma-related complications but is also a well-recognised source of interference in laboratory assays. We describe a case of a 62-year-old woman whose blood sample showed improper serum separation even after resampling. CASE REPORT: Centrifugation of a biochemistry specimen in a serum-separator tube received by the laboratory failed to separate any serum, nor did repeating the process at a longer duration. Repeat sampling only yielded a small volume of serum from which highly elevated total protein was noted upon analysis. Additional history from the treating clinician unveiled a diagnosis of multiple myeloma in this patient. DISCUSSION: This case represents one of the rare, but significant pre-analytical interferences caused by M-proteins.

Guidelines on retention of pathology records and materials (Version 2/2022).

No abstract available.

Light chain multiple myeloma: an evaluation of its biochemical investigations.

Multiple myeloma is a type of plasma cell dyscrasia, characterised by presence of paraprotein or monoclonal (M)-protein in serum or urine. The M-protein may consist of an intact immunoglobulin, the heavy chain only or the light chain only. The latter, designated as light chain multiple myeloma (LCMM) makes up almost 20% of myelomas. Clinical manifestation is often heralded by hypercalcaemia, renal impairment, normocytic normochromic anaemia and bone lesions, reflecting end-organ damage, collectively known as the acronym CRAB. In particular, free light chain nephrotoxicity accounts for the high prevalence of renal impairment seen in LCMM. This case illustrates a typical presentation of LCMM with focal discussion on its initial and diagnostic, as well as prognostic biochemical investigations.