TY - JOUR
T1 - Determination of reference intervals for common chemistry and immunoassay tests for Kenyan adults based on an internationally harmonized protocol and up-to-date statistical methods
AU - Omuse, Geoffrey
AU - Ichihara, Kiyoshi
AU - Maina, Daniel
AU - Hoffman, Mariza
AU - Kagotho, Elizabeth
AU - Kanyua, Alice
AU - Mwangi, Jane
AU - Wambua, Caroline
AU - Amayo, Angela
AU - Ojwang, Peter
AU - Premji, Zul
AU - Erasmus, Rajiv
N1 - Publisher Copyright:
© 2020 Public Library of Science. All rights reserved.
PY - 2020/7
Y1 - 2020/7
N2 - Background Due to a lack of reliable reference intervals (RIs) for Kenya, we set out to determine RIs for 40 common chemistry and immunoassay tests as part of the IFCC global RI project. Methods Apparently healthy adults aged 18-65 years were recruited according to a harmonized protocol and samples analyzed using Beckman-Coulter analyzers. Value assigned serum panels were measured to standardize chemistry results. The need for partitioning reference values by sex and age was based on between-subgroup differences expressed as standard deviation ratio (SDR) or bias in lower or upper limits (LLs and ULs) of the RI. RIs were derived using a parametric method with/without latent abnormal value exclusion (LAVE). Results Sex-specific RIs were required for uric acid, creatinine, total bilirubin (TBil), total cholesterol (TC), ALT, AST, CK, GGT, transferrin, transferrin saturation (TfSat) and immunoglobulin-M. Age-specific RIs were required for glucose and triglyceride for both sexes, and for urea, magnesium, TC, HDL-cholesterol ratio, ALP, and ferritin for females. LAVE was effective in optimizing RIs for AST, ALT, GGT iron-markers and CRP by reducing influence of latent anemia and metabolic diseases. Thyroid profile RIs were derived after excluding volunteers with anti-thyroid antibodies. Kenyan RIs were comparable to those of other countries participating in the global study with a few exceptions such as higher ULs for TBil and CRP. Conclusions Kenyan RIs for major analytes were established using harmonized protocol from welldefined reference individuals. Standardized RIs for chemistry analytes can be shared across sub-Saharan African laboratories with similar ethnic and life-style profile.
AB - Background Due to a lack of reliable reference intervals (RIs) for Kenya, we set out to determine RIs for 40 common chemistry and immunoassay tests as part of the IFCC global RI project. Methods Apparently healthy adults aged 18-65 years were recruited according to a harmonized protocol and samples analyzed using Beckman-Coulter analyzers. Value assigned serum panels were measured to standardize chemistry results. The need for partitioning reference values by sex and age was based on between-subgroup differences expressed as standard deviation ratio (SDR) or bias in lower or upper limits (LLs and ULs) of the RI. RIs were derived using a parametric method with/without latent abnormal value exclusion (LAVE). Results Sex-specific RIs were required for uric acid, creatinine, total bilirubin (TBil), total cholesterol (TC), ALT, AST, CK, GGT, transferrin, transferrin saturation (TfSat) and immunoglobulin-M. Age-specific RIs were required for glucose and triglyceride for both sexes, and for urea, magnesium, TC, HDL-cholesterol ratio, ALP, and ferritin for females. LAVE was effective in optimizing RIs for AST, ALT, GGT iron-markers and CRP by reducing influence of latent anemia and metabolic diseases. Thyroid profile RIs were derived after excluding volunteers with anti-thyroid antibodies. Kenyan RIs were comparable to those of other countries participating in the global study with a few exceptions such as higher ULs for TBil and CRP. Conclusions Kenyan RIs for major analytes were established using harmonized protocol from welldefined reference individuals. Standardized RIs for chemistry analytes can be shared across sub-Saharan African laboratories with similar ethnic and life-style profile.
UR - http://www.scopus.com/inward/record.url?scp=85087832159&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0235234
DO - 10.1371/journal.pone.0235234
M3 - Article
C2 - 32645006
AN - SCOPUS:85087832159
SN - 1932-6203
VL - 15
JO - PLoS ONE
JF - PLoS ONE
IS - 7 July
M1 - e0235234
ER -