Age- And Sex-Related Variations in Platelet Count in Italy: A Proposal of Reference Ranges Based on 40987 Subjects' Data

Ginevra Biino*, Iolanda Santimone, Cosetta Minelli, Rossella Sorice, Bruno Frongia, Michela Traglia, Sheila Ulivi, Augusto Di Castelnuovo, Martin Goegele, Teresa Nutile, Marcella Francavilla, Cinzia Sala, Nicola Pirastu, Chiara Cerletti, Licia Iacoviello, Paolo Gasparini, Daniela Toniolo, Marina Ciullo, Peter Pramstaller, Mario PirastuGiovanni de Gaetano, Carlo L. Balduini

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Background and Objectives: Although several studies demonstrated that platelet count is higher in women, decreases with age, and is influenced by genetic background, most clinical laboratories still use the reference interval 150-400 x 10(9) platelets/L for all subjects. The present study was to identify age- and sex-specific reference intervals for platelet count.

Methods: We analysed electronic records of subjects enrolled in three population-based studies that investigated inhabitants of seven Italian areas including six geographic isolates. After exclusion of patients with malignancies, liver diseases, or inherited thrombocytopenias, which could affect platelet count, reference intervals were estimated from 40,987 subjects with the non parametric method computing the 2.5 degrees and 97.5 degrees percentiles.

Results: Platelet count was similar in men and women until the age of 14, but subsequently women had steadily more platelets than men. The number of platelets decreases quickly in childhood, stabilizes in adulthood, and further decreases in oldness. The final result of this phenomenon is that platelet count in old age was reduced by 35% in men and by 25% in women compared with early infancy. Based on these findings, we estimated reference intervals for platelet count x 10(9)/L in children (176-452), adult men (141-362), adult women (156-405), old men (122-350) and, old women (140-379). Moreover, we calculated an "extended'' reference interval that takes into account the differences in platelet count observed in different geographic areas.

Conclusions: The age-, sex-, and origin-related variability of platelet count is very wide, and the patient-adapted reference intervals we propose change the thresholds for diagnosing both thrombocytopenia and thrombocytosis in Italy.

Original languageEnglish
Article number54289
Number of pages7
JournalPLoS ONE
Volume8
Issue number1
DOIs
Publication statusPublished - 31 Jan 2013

Keywords

  • IMMUNOHEMATOLOGICAL REFERENCE RANGES
  • ISOLATED POPULATION
  • CELL COUNT
  • THROMBOCYTOPENIA
  • PARAMETERS
  • ETHNICITY
  • ISOLATE
  • TRAITS
  • LOCI

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