South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa.
Department of Health, South Africa.
Trop Med Int Health. 2018 Jan;23(1):63-68. doi: 10.1111/tmi.13009. Epub 2017 Dec 4.
Paediatric laboratory reference intervals used in Africa and Asia may be derived from historical intervals of predominantly Caucasian infants in Europe or North America. These intervals may therefore not be compatible with the range of normality for developing country populations. We aimed to compare haematology and biochemistry parameters in healthy South African infants with local laboratory reference intervals.
We compared the baseline haematology and biochemistry results of 634 (316 male and 318 female) HIV-unexposed infants, aged 3-6 months, living in a rural area of the Western Cape Province, South Africa, against laboratory reference intervals supplied by the South African National Health Laboratory Services (NHLS). We calculated the percentage of observed values out of bound (in terms of lower and upper limits) compared to laboratory reference intervals.
Of the 634 healthy infants screened, 316 (49.84%) were male and 318 (50.16%) female. A majority (91.05%) had platelet counts above the laboratory reference interval upper limit (350 × 10 cells/l), while over half, 54.85% and 56.98% had mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) values below the lower limits of 77.0-105.0 fl and 26.0-34.0 pg, respectively. A small proportion were outside the reference limits for haematocrit, namely 15.71% below and 7.14% above the normal limits of 0.31-0.38 l/l. For male and female infants, 33.65% and 18.04% of alkaline phosphatase (ALP) values and 7.01% and 14.56% of alanine transaminase (ALT) values were above the upper limits, respectively. For male infants, 10.83% of gamma-glutamyl transferase (GGT) values, and for female infants, 31.11% of GGT values were below the lower limits of 12 U/l for males and 15 U/l for females. We observed no significant deviations (>10% out of bound) from NHLS reference intervals in the remaining haematology and biochemistry parameters measured.
Haematology and biochemistry parameters in apparently healthy South African infants deviate frequently from national laboratory reference intervals, including abnormalities consistent with subclinical hypochromic microcytic anaemia. It is important that clinical laboratory reference intervals for children are derived locally, rather than being adopted from Caucasian norms in developed countries, because clinical trials of vaccines, drugs and diagnostics are increasingly conducted in sub-Saharan Africa.
在非洲和亚洲使用的儿科实验室参考区间可能源自欧洲或北美的白种人婴儿的历史区间。因此，这些区间可能与发展中国家人群的正常范围不一致。我们旨在比较南非健康婴儿的血液学和生物化学参数与当地实验室参考区间。
我们比较了 634 名（316 名男性和 318 名女性）未暴露于艾滋病毒的 3-6 月龄婴儿的基线血液学和生物化学结果，这些婴儿居住在南非西开普省的一个农村地区，与南非国家卫生实验室服务局（NHLS）提供的实验室参考区间进行了比较。我们计算了观察值超出实验室参考区间（下限和上限）的百分比。
在筛选的 634 名健康婴儿中，316 名（49.84%）为男性，318 名（50.16%）为女性。大多数（91.05%）的血小板计数高于实验室参考区间上限（350×10 细胞/l），而超过一半（54.85%和 56.98%）的平均红细胞体积（MCV）和平均红细胞血红蛋白（MCH）值低于 77.0-105.0 fl 和 26.0-34.0 pg 的下限。一小部分婴儿的血液学参数超出了参考范围，即分别有 15.71%的婴儿的血细胞比容低于正常下限 0.31-0.38 l/l，7.14%的婴儿高于正常下限。男性和女性婴儿的碱性磷酸酶（ALP）值分别有 33.65%和 18.04%高于上限，丙氨酸氨基转移酶（ALT）值分别有 7.01%和 14.56%高于上限。男性婴儿中有 10.83%的γ-谷氨酰转移酶（GGT）值，女性婴儿中有 31.11%的 GGT 值低于男性 12 U/l 和女性 15 U/l 的下限。在所测量的其余血液学和生物化学参数中，我们没有观察到与 NHLS 参考区间有显著偏差（>10%超出范围）。
南非健康婴儿的血液学和生物化学参数经常偏离国家实验室参考区间，包括与亚临床低色素性小细胞性贫血一致的异常。重要的是，儿童的临床实验室参考区间应在当地确定，而不是采用来自发达国家的白种人标准，因为疫苗、药物和诊断的临床试验越来越多地在撒哈拉以南非洲进行。
