Search

Background: Transient hyperphosphatasemia (TH) is an often unnoticed benign entity, primarily affecting children below 5 years of age. However, the prevalence among healthy children is unknown. We used data from a Swedish pediatric reference interval project to estimate the prevalence of high alkaline phosphatase (ALP) among healthy children and to calculate pediatric reference intervals. Methods: Blood was collected from 699 subjectively healthy children aged 6 months to 18 years. After exclusion of subjects with high ALP, age- and gender-specific reference intervals were calculated. Results: Six children had ALP levels >16.7 µkat/l (>1,000 U/l), including 4 females and 2 males aged 7-22 months. The prevalence in the age group from 6 months to 2 years was 6.2% (6/97). None of the older children had levels of ALP >16.7 µkat/l. The study did not include the follow-up of these apparently healthy children. Consequently, conditions others than TH explaining the elevated ALP could not be excluded. However, general chemistry analyses, such as liver enzymes, calcium, intact PTH and vitamin D, were essentially normal in these children. Conclusions: The prevalence of high ALP among subjectively healthy children was approximately 2.4% below 5 years of age and 6.2% below 2 years. Reference intervals vary with age and gender.

Very few high-quality studies on paediatric reference intervals for general clinical chemistry and haematology analytes have been performed. Three recent prospective community-based projects utilising blood samples from healthy children in Sweden, Denmark and Canada have substantially improved the situation. ConclusionThe present review summarises current reference interval studies for common clinical chemistry and haematology analyses.

Many previous studies on reference intervals are hampered by the inclusion of only hospital-based populations of children and adolescents.This study included 694 children, evenly distributed from 6 months to 18 years of age. They were recruited as volunteers at child care units and schools. All subjects were apparently healthy. A questionnaire on diseases and medications was filled out by parents and by the older children.Alanine aminotransferase (ALT), albumin, aspartate aminotransferase (AST), bilirubin, conjugated bilirubin, C-reactive protein (CRP), creatine kinase (CK), Gamma-glutamyltransferase (GGT), HbA1c (mono S and IFCC calibrations), lactate dehydrogenase (LD), myoglobin and panceratic amylase were analyzed on Abbott Architect ci8200, and for HbA1c on Tosoh G7 and a mono S-system. Age- and gender-related 2.5th and 97.5th percentiles were estimated. For some analytes the differences to comparable studies were substantial.The study gives age- and gender-specific pediatric reference intervals, measured with modern methods for a number of important analytes. The results emphasize the importance to evaluate pediatric reference intervals in different populations and ethnic groups including only healthy subjects.

Reference intervals are crucial decision-making tools aiding clinicians in differentiating between healthy and diseased populations. However, for children such values often are lacking or incomplete. Blood samples were obtained from 689 healthy children, aged 6 months to 18 years, recruited in day care centers and schools. Hematology and anemia analytes were measured on the Siemens Advia 2120 and Abbott Architect ci8200 platforms (hemoglobin, erythrocyte volume fraction [EVF], erythrocytes, mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCH], mean corpuscular hemoglobin concentration [MCHC], reticulocytes, leukocytes, lymphocytes, monocytes, neutrophils, eosinophils, basophils, platelets, iron, transferrin, transferrin saturation). Age- and gender-specific pediatric reference intervals were defined by calculating 2.5th and 97.5th percentiles. The data generated is primarily applicable to a Caucasian population, but could be used by any laboratory if verified for the local patient population.

Pediatric reference intervals for thyroid hormones, prolactin and lipids are of high clinical importance as deviations might indicate diseases with serious consequences. In general, previous reference intervals are hampered by the inclusion of only hospital-based populations of children and adolescents. The study included 694 children, evenly distributed from 6 months to 18 years of age. They were recruited as volunteers at child care units and schools. All subjects were apparently healthy and a questionnaire on diseases and medications was filled out by parents and by the older children. TSH, free T4, free T3, total cholesterol, LDL, HDL, triglycerides and prolactin were analyzed on Abbott Architect ci8200. Age- and gender-related 2.5 and 97.5 percentiles were estimated. The thyroid hormone levels were similar to previous data for the Abbott Architect platform, but exhibited differences from studies performed with other methods. Prolactin displayed wide reference ranges, but relatively small age-related changes, and a marginal difference between sexes during adolescence. Reference intervals for lipids in the different age groups are known to vary geographically. Levels of LDL and total cholesterol were higher than those reported for children in Canada, but lower than those reported for children in China. The study gives age- and gender- specific pediatric reference intervals, measured with modern methods for a number of important analytes. The results presented here differ from previously recommended reference intervals. In many earlier studies, retrospective hospital-based reference intervals, which may include various sub-groups have been presented. By non-hospital studies it is possible to avoid some of these biases.

Reference intervals are crucial decision-making tools aiding clinicians in differentiating between healthy and diseased populations. However, for children such values often are lacking or incomplete.Blood samples were obtained from 692 healthy children, aged 6 months to 18 years, recruited in daycare centers and schools. Twelve common general clinical chemistry analytes were measured on the Abbott Architect ci8200 platform; sodium, potassium, chloride, calcium, albumin-adjusted calcium, phosphate, magnesium, creatinine (Jaffe and enzymatic), cystatin C, urea and uric acid.Age- and gender specific pediatric reference intervals were defined by calculating the 2.5th and 97.5th percentiles.The data generated is primarily applicable to a Caucasian population when using the Abbott Architect platform, but could be used by any laboratory if validated for the local patient population.