original article platelet parameters in healthy subjects ... 05 parameters(1).pdf · by automation...

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วารสารโลหติวทิยาและเวชศาสตรบรกิารโลหติ ปที ่11 ฉบบัที ่2 เมษายน-มถินุายน 2544

Automated blood cell analyzers have beenevolving since the late 1960s and the instru-ments now are available and capable of iden-tifying, mixing and analysing blood samples at

a rate of up to 120/hour with accuracy and pre-cision. Automated particle counting and siz-ing technology have made platelet count andsize readily available as part of the routine au-tomated blood count.1-5 Platelet parameters maybecome increasingly important in evaluating theintegrity of the thrombocytic function. For ex-ample, particle sizing has been used to distin-

Original ArticlePlatelet Parameters in Healthy Subjects Analysedby Automation Analyser

Kritsana Pathepchotiwong, Pisit Dhareruchta, and Warina AdirojananonDepartment of Clinical Microscopy Faculty of Medical Technology, Mahidol University,Siriraj Hospital, Bangkok. Thailand 10700.

Abstract: Blood sample collected after venipuncture from healthy volunteers were used to deter-mine platelet count (438 cases), mean platelet volume (MPV) (438 cases), plateletcrit (PCT) (255cases) and platelet distribution width (PDW) (255 cases). Recently, the introduction of automatedcell analyser with platelet parameters have become available on a routine basis, so it is important toevaluate platelet size relationship. This study established reliable reference ranges for these plateletparameters, while taking into consideration the effects of age and sex. The higher platelet count inwomen was confirmed. An inverse non-linear relationship between the platelet count and the meanplatelet volume was found. Plateletcrit showed no variation with respect to age, and a direct linearrelationship was found between PCT and platelet count with r = 0.879. PDW showed no variationwith respect to age. These platelet parameters are helpful as diagnostic aids.Key Words : Platelet count Mean platelet volume Platelet crit Platelet distribution widthThai J Hematol Transf Med 2001;11:93-100.

Received May 16, 2001. Accepted June 2, 2001.Requests for reprints should be addressed to Miss KritsanaPathepchotiwong, Department of Clinical Microscopy,Faculty of Medical Technology, Mahidol University, SirirajHospital Bangkok. 10700 Thailand.

94 Kritsana Pathepchotiwong, et al.

Thai Journal of Hematology and Transfusion Medicine Vol. 11 No. 2 April-June 2001

guish immune from hypersplenic6 or infiltrationthrombocytopenia7. The platelet count and themean platelet volume (MPV) have been sug-gested as useful parameters.8, 9

The MPV may be as important as the plate-let count in determining platelet homeostasis10

and the thrombocytocrit (PCT) has been pro-posed as a measurement of platelet mass.11 Inaddition, the MPV may serve as a guide topredict the risk of hemorrhage in thrombocy-topenic patients12, patients with thrombocytope-nia resulting from loss or consumption has ahigher MPV than with marrow failure.13-15

The purpose of this study is to establishtentative reference ranges for the platelet count,MPV, PCT and PDW in a selected population,while the effects of age and sex variables aretaken into consideration. This study is pro-spective study.

Materials and MethodsVolunteers were healthy joined the check

up program, and had not taken any drugs. Theblood samples used in this evaluation weredrawn by venipuncture into potassium-EDTAanticoagulant tubes, allowed to stand at roomtemperature after venipuncture for two to three

hours before these studies were done. TheCoulter Counter model Max M (Coulter Elec-tronics, Hialeak, Florida) was used to determineplatelet count, MPV, PCT and PDW. The re-sults were grouped by age according to decadeand by sex.

ResultsPlatelet count

Table 1 represents the results for all the plate-let parameters studied. The mean platelet countfor the entire group of 438 people, ranging inage from 16 to 60 years was 272 x 109/L. Theresults of platelet count are diagramatic in fig1. The platelet counts in male and female werenot significantly different (table 2). The groupswere divided into ten years intervals (table 3).

Fig. 1 Histogram of the distribution of plateletcount

Numb

er

Platelet count (x 109/:L)

Plateletcount (x109/L)MPV (fL)PCT (%)PDW (%)

Table 1. Platelet parameters in healthy subjectsParameter N X±±±±±SD Variance SE Kurtosis SE skew Kurtosis Skewness Range Min-Max

438

438255255

272.34±56.57

7.945±0.7150.221±0.03815.786±0.425

3,200.74

0.5110.0010.181

0.233

0.2330.3040.304

0.117

0.1170.1530.153

0.117

0.782-0.1091.116

0.381

0.4370.3660.756

323.000

115.300110.181112.700

151 - 474

5.6 - 10.90.141 - 0.32214.9 - 17.6

95Platelet Parameters in Healthy Subjects Analysed


Comparison platelet count between age groupwas significantly different at age 26-35 and age36-45, age 26-35 and age 46-55.Mean platelet volume

The results are summarized in table 1, fig 2.The mean platelet volume for the entire groupof 438 people was 7.945 fl. Comparison be-tween male and female was significantly differ-ent that female MPV were higher than maleMPV. (Table 2) There was no evidence of apatterned relationship when different ages werecompared. When the MPV was compared as afunction of platelet count (Fig 3), there was found

to be an inverse, nonlinear relationship betweenthe two parameters. (correlation coefficient -0.415, table 4)

Fig. 2 Histogram of the distribution of MPV

Numb

er

MPV (fL)

Platelet count (x109/L)

MPV (fL)

PCT (%)

PDW (%)

Table 2. Comparison of platelet parameters in males and femalesParameter Sex n X±±±±±SD t-test

MF

MF

MF

MF

157281

157281

101154

101154

267.32±55.51275.15±57.07

7.80±0.668.02±0.73

0.21±0.0350.23±0.039

15.87±0.4415.73±0.41

p = 0.140

p = 0.002

p = 0.021

p = 0.010

Scheffe testPlatelet count : Two group are significantly different at p <0.05 (Age 26-35 : Age 36-45, Age 26-35 : Age 46-55)

Table 3. Platelet parameters in age (mean±SD)Age

(years)Platelet count(x109/L) (n)

MPV(fL) (n)

PCT(%) (n)

PDW(%) (n)

266.16±62.28 (70)1260.82±49.91 (131)*279.87±56.44 (159)*285.03±58.91 (73)**

7.81±0.72 (70)18.07±0.73 (131)7.93±0.71 (159)7.91±0.67 (73)1

0.24±0.04 (13)10.21±0.04 (73)10.22±0.03 (103)0.23±0.04 (61)1

15.75±0.42 (13)115.81±0.41 (73)115.76±0.44 (103)15.79±0.42 (61)1

16-2526-3536-4546-55



PlateletcritThe information gathered for PCT is pre-

sented in table 1, and fig 4. Comparison valuebetween male and female was significantly dif-ferent. The ranges of PCT in each of the agegroup remained relatively stable. This was adirect, approximately linear relationship notedbetween PCT and platelet count (Fig 5) andcorrelation coefficient 0.879 (Table 4).Platelet distribution width (PDW)

The results are summarized in table 1, and

Fig. 3 Relationship between MPV and platelet count

MPV

(fL)

PLT count (109/L)

** Correlation is significant at the 0.01 level (2 tailed) * Correlation is significant at the 0.05 level (2 tailed)

Table 4. Show the correlation coefficientPlatelet count (x109/L) MPV (fl) PCT (%) PDW (%)

1.000- 0.415**0.879**- 0.137*

- 0.415**1.0000.008- 0.067

0.879**0.0081.000

- 0.157*

- 0.137*- 0.067- 0.157*1.000

Platelet countMPVPCTPDW

Fig. 4 Histogram of the distribution of PCT

Numb

er

PCT (%)



Fig. 6 Histogram of the distribution of PDW

Numb

er

PDW (%)

fig. 6 PDW in male and female were signifi-cantly different (table 2) but the ranges of PDWin each of the age groups were not significantlydifferent (table 3). When the PDW is comparedas a function of platelet count (Fig 7), therewas found no significant pattern.

DiscussionThe automated platelet counting system has

several advantages over existing countingmethod. The machine is relatively easy to op-erate and can rapidly process a large numberof samples.

The platelet count of healthy males is com-pared to that of healthy females. A higher plate-let count in women was not significantly differ-ent than that in men. Sloan (1951)16, made on agroup of physiology students, where no signifi-cant sex difference was found but Stevens RF,Alexander MK (1977)17 and Bain B, Forster T

(1980)18 found the platelet count in women higherthan that in men. There have been number ofinvestigations of possible periodic fluctuationsof the platelet count during the menstrual cycle19

and the bulk of the evidence indicating a fall inthe count at the onset of menstruation with thehighest values occuring in mid-cycle. A varia-tion in the platelet count of women from this

Fig. 5 Relationship between PCT and platelet count

PCT (

%)

Platelet count (109/L)



cause may provide explanation for the widerrange and skewed distribution of the counts ofthe female donors in the present series. Plate-let count seemed to vary somewhat with age.

Automated blood counts including both

platelet count and MPV are frequently the firsthematologic data available to the physician13.The nonlinear, inverse relation between MPVand platelet count in normal subjects definesthe platelet values in subjects with apparently

Fig. 7 Relationship between PDW and platelet count

PDW

(%)

Platelet count (109/L)

Fig. 8 Relationship between PDW and MPV

PDW

(%)

MPV (fL)



normal platelet production and survival. Thisagrees with previous findings of Granham SS.20It is known that the MPV increases as platelethalf-life decrease and that large platelets arefunctionally different from small platelets.14, 21

The PCT has been proposed as a measure-ment of platelet mass. PCT showed significantvariation in males and females but PCT showedno significant variation over the range of agesstudied. Plotting mean PCT(%) versus plateletcounts between 150-450 (x 109/L), (Fig 5), a di-rect, linear relationship was suggested betweenPCT and platelet count.

Platelet size is widely distributed in normalsubjects. The platelet distribution width (PDW)increases nonlinearly as the MPV increases.(Fig8) PDW is increased in megaloblastic or aplas-tic anemia, in leukemic patients receiving che-motherapy, and in chronic myeloid leukemia.13The PDW may also be erroneously increased iffragmented red cells or leukocyte fragmentsbroaden the cell distribution population. Thecauses of a true increased PDW are unclear,but they are believed to be related to mega-karyocytic ploidy.22

Reference11. Bessman JD. Evaluation of whole blood platelet

counts and particle sizing. Am J Clin Pathol 1980;74:157-62.

12. Dalton WT, Bollinger P, Drewinko B. A side byside evaluation of four platelet counting instruments.Am J Clin Pathol 1980;74:119-35.

13. Mayer K, Chin B, Magnes J, et al. Automatedplatelet counters: A comparative evaluation of

latest instrumentation. Am J Clin Pathol 1980;74:135-50.

14. Ross DW, Ayscue L, Gulley M. Automated plateletcounts: Accuracy, precision and range. Am J ClinPathol 1980;74:157-67.

15. Rowan RM, Fraser C, Gray JH, et al. The CoulterCounter S-Plus: The shape of things to come. ClinLab Haematol 1979;19-40.

16. Karpatkin S, Freedman ML. Hypersplenic thromb-ocytopenia differentiated from increased peripheraldestruction by platelet volume. Ann Intern Med1978;89:200-6.

17. Roper PR, Johnson D, Austin J, et al. Profile ofplatelet volume distribution in normal individualsand in patients with acute leukemia. Am J Clinpathol 1977;68:449-57.

18. Ahmed Y, van Iddekinge B, Paul C, Sullivan MHE,Elder MG. Retrospective analysis of platelet num-ber and volumes in normal preganancy and in pre-eclampsia. British J obst Gyn 1993;100:216-20.

19. Howarth S, Marshall LR, Barr AL, Evans S, PontreM, Ryan N. Platelet indices during normal preg-nancy and pre-eclampsia. British J BiomedicalScience 1999;56:20-2.

10. Thompson CB, Diaz DD, Quinn PG, et al. The roleof anticoagulation in the measurement of plateletvolumes. Am J Clin Pathol 1983;80:327-32.

11. Rebuck JW, Riddle JM, Brown MG, et al. Volumet-ric and ultrastructural studies of abnormal plate-lets. In: SA Johnson, et al (eds). Blood platelets.Boston: Little, Brown and Co 1961:533-52.

12. Eldor A, Avitzour M, Or R, Hanna R, Penchas S.Prediction of haemorrhagic diathesis in thromb-ocytopenia by mean platelet volume. Br Med J1982;285:397-400.

13. Bessman JD, Williams LJ, Gilmer PR. Mean plate-let volume the inverse relation of platelet size andcount in normal subjects, and artifact of other par-ticles. Am J Clin Pathol 1981;76:289-93.



14. Levin J, Bessman JD. The inverse relationbetween platelet volume and platelet number.Abnormalities in hematologic disease and evidencethat platelet size does not correlate with plateletage. J Lab Med 1983;101:295-307.

15. Nelson RB III, Kehl D. Electronically determinedplatelet indices in thrombocytopenic patient. Can-cer 1981;48:954-6.

16. Sloan AW. The normal platelet count in man. AmClin Patho 1951;4:37.

17. Stevens RF, Alexander MK. A sex difference inthe platelet count. Br J Haematol 1977;37:295-300.

บท คดั ยอ: จาก การ ศึกษา ตัวอยาง เลือด ใน ประชากร ที่ มี สุขภาพ แข็งแรง เพื่อ ดู คา ของ จํานวน เกร็ด เลือด (438 ราย)คาเฉลีย่ ของ ปรมิาตร เกรด็ เลอืด (438 ราย) เกรด็ เลอืด อดั แนน (255 ราย) และ การ กระจาย ของ ขนาด เกรด็ เลอืด (255ราย) พารามเิตอร ตางๆ ของ เกรด็ เลอืด เหลา นี ้ม ีความ สาํคญั ใน การ ศกึษา ความ สมัพนัธ ของ เกรด็ เลอืด ใน งาน ประจาํ วนัเพือ่ นาํ ไป สู การ ชวย ใน การ วนิจิฉยั โรค ตางๆ และ ได ศกึษา พารามเิตอร ของ เกรด็ เลอืด ใน แง ของ เพศ และ อาย ุอกี ดวย พบวา จาํนวน เกรด็ เลอืด ใน เพศ หญงิ ม ีมาก กวา ใน เพศ ชาย ความ สมัพนัธ ของ จาํนวน เกรด็ เลอืด และ คาเฉลีย่ ของ ปรมิาตร เกรด็เลือด เปน แบบ non-linear relationship เกร็ด เลือด อัด แนน ใน ชวง อายุ ตางๆ กัน ไม มี ความ แตก ตางกัน และ ความสมัพนัธ ระหวาง เกรด็ เลอืด อดั แนน กบั จาํนวน เกรด็ เลอืด ม ีความ สมัพนัธ ที ่ดี (r = 0.879) และ การ กระจาย ของ ขนาด เกรด็เลอืด ใน ชวง ของ อาย ุตางๆ กนั ก ็ไม ม ีความ แตก ตางกนั เชน เดยีว กนั พารามเิตอร ตางๆ ของ เกรด็ เลอืด ม ีประโยชน ชวยใน การ วนิจิฉยั โรค ไดKey Words : Platelet count Mean platelet volume Platelet crit Platelet distribution widthวารสารโลหิตวิทยาและเวชศาสตรบริการโลหิต 2544 ;11:93-100.

การวเิคราะหคาของเกรด็เลอืดในประชากรทีม่สีขุภาพแขง็แรงโดยใชเครือ่งวเิคราะหอตัโนมตัิ

กฤษณา ปทปีโชตวิงศ, พสิษิฐ ธารรีชัต และ วารณิา อดโิรจนานนท.ภาควิชาจุลทรรศนศาสตรคลินิก คณะเทคนิคการแพทย มหาวิทยาลัยมหิดล โรงพยาบาลศิริราช กรุงเทพฯ 10700

18. Bain B, Forster T. A sex difference in the plateletcount. Thromb Haemost 1980;43:131-2.

19. Morley A. A platelet cycle in normal individuals.Australasian Annals of Medicine 1969;18:127.

20. Granham SS. Automated Platelet Sizing Parametersan a Normal Population. Am J Clin Pathol 1987;87:365-9.

21. Thompson CB. Jakubowski the pathophysiologyand clinical relevance of platelet heterogenicity.Blood 1988;721:1- 8.

22. Bessmann JD. New parameters on automatedhematology instrument. Lab Med 1983;14:488.

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