Laboratory reference values for healthy adults from southern Tanzania

Area of Science:

• Clinical Laboratory Science
• Public Health
• Immunology

Background:

• Establishing accurate clinical reference ranges is crucial for diagnosing and managing diseases.
• Existing laboratory reference ranges are often derived from populations in developed countries, potentially leading to misdiagnosis in other regions.
• There is a need to define region-specific reference ranges for laboratory parameters.

Purpose of the Study:

• To establish and discuss reference ranges for common laboratory parameters in healthy adults residing in southern Tanzania.
• To compare these newly defined ranges with those established in developed countries and other African regions.

Main Methods:

• A population-based sample of 301 healthy adult volunteers (145 women, 156 men) aged 19-48 years from Mbeya, Tanzania, were recruited.
• Standard laboratory methods were used to determine clinical chemistry (CC), haematology, and lymphocyte immunophenotyping (LIP) parameters.
• Medians and nonparametric 95% reference ranges were calculated and compared with international and regional data.

Main Results:

• Poor agreement was observed between Tanzanian and developed country reference ranges for CC parameters (average concordance 80.9%-86.7%).
• Haematology ranges from the USA showed 86.3% concordance, while Sub-Saharan African (SSA) ranges showed 82.5%-94.5% concordance.
• LIP reference range agreement was 87.5% with German values but higher (91.7%-95.8%) with other SSA sites.

Conclusions:

• Clinical laboratory reference ranges from developed countries are inadequate for use in Sub-Saharan Africa.
• Laboratories in SSA should develop their own reference ranges or utilize values determined under similar environmental and population conditions.
• The reference ranges established in this study are more appropriate for the Tanzanian population than those from developed countries.