Page 478 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

462 PART 6 ■ Neoplastic Disorders

nor l v lues or leukocytes n pl telets. T e e n corpus- Co plic tions o PRV inclu e thro bosis n p r oxi-

cul r volu e is usu lly within nor l li its (p tients with c l he orrh ge. T e thro bosis see s to be rel te to the

PRV usu lly h ve low e n corpuscul r volu e bec use o height o the re cell volu e with subsequent incre se in

rrow epletion o iron resulting in icrocytic re cells). bloo viscosity. Whole bloo viscosity pursues r ther line r

Seru erythropoietin levels re nor l or elev te bec use r te o rise, n ost physici ns pre er to keep the p tient’s

o n incre se re cell pro uction. T e seru erythropoi- he tocrit below 45%. Incre se whole bloo viscosity con-

etin level c n o en be use to istinguish this ro PRV. tributes to v scul r occlusions n reversible lesions, inclu -

An elev te he tocrit bove the level o 50% or gre ter ing cerebr l n yoc r i l in rction, s well s shortness

in the bsence o ehy r tion is highly suggestive o the o bre th n hot ushes, prob bly c use by circul tory is-

i gnosis, n he tocrit gre ter th n 60% or en or 56% turb nce. P tients with bloo viscosity higher th n twice

or wo en is consistent with n elev te re cell ss. T e the nor l e n v lue y be in nger o v scul r occlu-

oxygen s tur tion shoul be nor l, n i the p tient is sion. A correl tion h s been reve le ong the p r eters

s oker, the c rboxyhe oglobin level shoul lso be nor l. o re bloo cell rheologic l properties, he ost sis, n is-

Ly phocyte popul tions in p tients with PRV e - e se severity.

onstr te n ltere CD4/CD8 r tio, inly bec use o In so e c ses, isor ers in the rheologic l pheno en o

ecre se CD8 subpopul tion. Incre se ly phocyte ctiv- re bloo cells re triggering ech nis in the evelop-

ity h s lso been observe . Interleukin-2 (IL-2) pro uction ent o the DIC syn ro e.

is signif c ntly higher; the ly phoproli er tive response both In the chronic ph se o PRV, p tients with thro bohe-

to phytohe gglutinin n IL-2 is lso gre ter in ly pho- orrh gic co plic tions h ve higher pl telet counts, ore

cytes ro PRV p tients. T ese observ tions suggest th t severe pl telet ggreg tion e ects, n incre se pl s lev-

p tients y lso su er ro n ltere ly phoi line ge. els o bet thro boglobulin n f brinopepti e A co p re

Te bone rrow is hypercellul r (Fig. 23.9) with with p tients who o not h ve co plic tions. However,

incre se pro uction o ll three cell lines, especi lly the re thro bohe orrh gic co plic tions re not pre ict ble by

cell series. So e investig tors believe th t bone rrow ch nges in these p r eters in in ivi u l p tients uring the

ex in tion is not necess ry or i gnosis. Others believe chronic ise se ph se.

th t the bone rrow histology shoul be ex ine n Te pl s level o tissue pl s inogen ctiv tor ntigen

cytogenetic n lysis or the BCR-ABL ut tion shoul be (t-PA-Ag) is signif c ntly ecre se in p tients with PRV

per or e . An occ sion l p tient with CML c n present co p re with he lthy in ivi u ls. In contr st, p tients

with erythrocytosis, lthough this is istinctly unusu l. with spurious polycythe i n secon ry polycythe i

exhibit signif c ntly incre se concentr tions o t-PA-

Ag. T ere is no signif c nt i erence in t-PA-Ag levels in
Abnormalities of Hemostasis and

Coagulation polycythe ic p tients with or without thro boe bolic
ise se.

P tients with PRV requently e onstr te co plex o

he orheologic l isor ers (high bloo viscosity t i erent Other Laboratory Assays

r tes o evi tion, intensif e re bloo cell ggreg tion, n

ecre se e or bility o these cells) n he oco gul tion Erythropoietin excretion in the urine is ecre se in

isor ers. PRV, in contr st to the other kin s o polycythe i s.

R ioi uno ss y o erythropoietin h s been use to is-

tinguish between PRV n other or s o erythrocytosis.

L bor tory f n ings th t support i gnosis o PRV co -

p re with other or s o polycythe i re n bsence o

he osi erin ro the bone rrow n n incre se LAP

score. In ition, hyperurice i n hyperuricosuri

re present in ore th n h l o PRV p tients t i gno-

sis bec use o excess nucleic ci egr tion. T e level o

uric ci p r llels incre ses in severity o PRV s the ise se

progresses.

T ro bocytosis lso see s to be rel te to both the risk

o thro bosis n he orrh ge. T e level o thro bocytosis

see s to be rel te , n ost he tologists pre er to keep

the pl telet count below 400,000. Qu lit tive bnor lities

o pl telets lso ight contribute to PRV co plic tions.

FIGURE 23.9 Bone rrow clot section o PV in the proli er - Abnor lities in pl telet responsiveness to n tur lly occur-

tive st ge showing hypercellul r rrow with rke erythroi ring pl telet inhibitors such s prost gl n ins, incre se
hyperpl si . (Fro McCl tchey KD. Clinical Laboratory Medicine, levels o thro box nes (in ucers o pl telet ggreg tion),

2n e , Phil elphi , PA: Lippincott Willi s & Wilkins, 2002.) n bnor l levels o n tur lly occurring ntico gul nts