Essential Thrombocythemia : 15 Years of Experience at the Hematology Department, Algies, Algeria.pdf

Background: Essential Thrombocythemia (ET) is a rare myeloproliferative disorder. Data on its epidemiology and clinical features in Algeria are limited.

Methods: We conducted a retrospective analysis of ET cases observed in our department, focusing on incidence, clinical and biological characteristics, diagnostic approaches, and treatment patterns.

Results: Over the study period, an average of 1.6 cases per year were recorded. The mean age at diagnosis was 59 years, with a predominance of females. ET was incidentally discovered in 72% of cases. Diagnosis relied on complete blood counts, JAK2 V617F mutation testing, and bone marrow biopsy, which was performed in 100% of patients. JAK2 testing was introduced in 2014 and is now recognized as a major molecular diagnostic marker. Myelosuppressive therapy with Hydroxyurea was reserved for symptomatic cases or patients with cardiovascular risk factors.

Conclusion: ET in our cohort shows a low incidence, female predominance, and frequent incidental discovery. Our findings underscore the importance of a multidisciplinary approach and access to molecular diagnostics for accurate diagnosis and optimal management of ET patients.

1. SE BELAKEHAL , M DJILALI, H OTSMAN , F TALBI,
MC RAHALI, L SAHRAOUI, FZ ARDJOUN
HEMATOLOGY DEPARTMENT
Essential Thrombocythemia :
15 Years of Experience at the
Hematology Department, Algies, Algeria

2. Outline
▪Historical Background –A Brief
Look Back…
▪Objectives of the Study
▪Patients and Methods
▪Frequency
▪Distribution by Age and Sex
▪Circumstances of Discovery
▪Diagnostic Tools
▪Comments
▪Conclusion
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3. Introduction
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▪Essential Thrombocythemia (ET) is a chronic
myeloproliferative neoplasm characterized by a
sustained increase in platelet count, often discovered
incidentally or through thrombo-hemorrhagic
complications.
▪Understanding its clinical, biological, and evolutionary
features is crucial for accurate diagnosis and
optimal management.
▪This study provides an overview of 15 years of
experience with ET in the Hematology
Department of the Central Hospital.

4. Historical Background –A Brief Look Back…
▪The concept of myeloproliferative
syndrome (MPS)was introduced by
William Dameshek, the founder of
the journal Blood.
▪In 1951, he described the common
features of myeloproliferation,
highlighting the shared biological
mechanisms underlying disorders
such as polycythemia vera,
essential thrombocythemia, and
myelofibrosis.
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5. Objectives
1.To identify the clinical and biological
characteristics of Essential Thrombocythemia (ET)
in the Hematology Department of the Central
Hospital.
2.To assess the management approaches
implemented for this disease in the Hematology
Department.
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6. PATIENTS ET METHODES
▪Type of Study:Retrospective and descriptive
▪Duration:15 years [January 2000 –December 2014]
▪Number of Patients:25
▪Our diagnostic approach was based on:
▪Clinical evaluation
▪Complete blood count (CBC) with peripheral blood smear
▪Bone marrow biopsy
▪JAK2 mutation testing in selected cases
▪Iron and inflammatory work-up
▪Abdominal ultrasound
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7. TWENTY -FIVE CASES
MEETING THE CRITERIA OF
THE STUDY FORM WERE
INCLUDED.
Results

8. Incidence (1)
▪10 000 sujets sains inclus (âge < 65 ans)
▪Thrombocytose > 400.10
9
/l dans 99 cas
▪3 avaient une TE, 1 a développé une TE
▪Prévalence : 400 cas par Million hab (1)
(1)Ruggeri, Ann Intern Med,
2003
(2)Rev Alg Hem, 2009, N°1,
Etude prospective
italienne de 04 ans
[de 1993 à 1996]
▪ Etude rétrospective en Algérie : 1996 à 2005
Incidence : 0,06 cas par 100 000 hab/an (2)
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9. Incidence (2)
▪The search was restricted to human studies written in English or French and
published between January 1, 2000, and December 6, 2012
▪484 articles identified in EMBASE
The estimated incidenceof ET was between 0.38 to 1.7 per 100 000
per year
Moulard et al. European Journal of Haematology, 2013
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10. Incidence (3)
M Maynadié et al, Heamatologica. 2011 ▪ The incidence also increases with age.
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11. Our Study : Frequency
Distribution of New Cases per Year
25 cases over 15 years : rareoccurrence
Average frequency = 1.66 cases per year
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12. Distribution by Age and Sex
Henrik Frederiksen et col. Blood, 2011.
80%
Sex-ratio = 1,98 F > H
Pic: 60 ans
Quelques formes : Femmes 30 ans
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13. Our Study: Distribution by Age and Sex
Mean age = 59 years [range: 24–86 years]
Sex-ratio = 2
17 F / 8 H
Femmes
Hommes
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14. Circumstances of Discovery
N (%)
Souvent découverte fortuitement lors d’un bilan
biologique
18 72%
Complications (02 thromboses veineuses et 01 IDM) 03 12%
Signes d’hyperviscosité 03 12%
Douleur de HCD gauche (SPMG) 01 04%
Total 25 100%
Diagnostic delay = 7 days to 60 months
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15. Clinical Signs
N (%)
Splénomégalie 3 10%
Complications thrombotiques 2 10%
Syndrome hémorragique
(ecchymoses)
1 4%
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16. Diagnostic Tools
Moyens diagnostiques N (%)
Hémogramme 25 (100%)
taux moyen de plaq = 1.018.420 élts/mm³
[623 000 à 1960 000]
taux moyen des GB = 13962 élts/mm³
[6860 à 52 400]
taux moyen d’Hb = 12,8 g/dl [8,9 à 14,6]
BOM : hyperplasie des MGK 25 (100%)
Recherche de la mutation JAK2V617F 12 (48%) : 2014-2015
Positive 11 cas (44%)
Echo. Abdominale : recherche de SPMG 25 (100%)
Caryotype : recherche de transcrit BCR-ABL 2 (8% )
Diagnosis of Exclusion
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17. Essential Thrombocythemia (ET) diagnostic criteria according
to the World Health Organization (2008 edition),
▪Thrombocytosis > 600 × 10⁹/L
▪Bone Marrow (BM):
•Proliferation of the megakaryocytic
lineage
•Presence of large, mature
megakaryocytes
▪No evidence of:
•Polycythemia vera (PV)
•Chronic myeloid leukemia (CML)
•Myelofibrosis
•Myelodysplastic syndrome (MDS)
•Reactive (secondary) thrombocytosis
JAFFE E.S. et al. Blood. (2008)
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18. Diagnostic Algorithm for Essential Thrombocythemia (ET)
Based on WHO 2008 Criteria
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19. Diagnostic Criteria for Essential Thrombocythemia (ET) –
British Committee for Standards in Haematology(BCSH), 2014
▪A1 : Thrombocytosis > 450 × 10⁹/L
▪A2 : Presence of an acquired mutation (JAK2 V617F, CALR, or MPL)
▪A3 : No evidence of:Polycythemia vera (PV)Chronic myeloid leukemia
(CML)MyelofibrosisMyelodysplastic syndrome (MDS)
▪A4 : Absence of reactive thrombocytosis (iron deficiency, inflammatory
syndrome)
▪A5 : Bone marrow (BM):Proliferation of the megakaryocytic
lineagePresence of large, mature megakaryocytes
Diagnostic de certitude :
A1-A3 ou A1 + A3-A5
2014 John Wiley & Sons Ltd, British
Journal of Haematology
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20. Essential thrombocythemia: 2024 update on diagnosis,
risk stratification, and management
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21. Essential thrombocythemia: 2024 update on diagnosis, risk
stratification, and management
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22. Essential thrombocythemia: 2024 update on diagnosis, risk
stratification, and management
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23. Treatment of Essential Thrombocythemia
▪Cytoreductive treatment is recommended:
▪In elderly patients (> 60 years) when the platelet count
exceeds 1,500 ×10⁹/L
▪In younger patients (< 60 years) with a platelet count >
1,000 ×10⁹/L and vascular risk factors
▪Asymptomatic forms with platelet counts < 1,000 ×10⁹/L:
close monitoring is advised
▪In Italy, systematic aspirin prophylaxis is not recommended
in asymptomatic ET patients, as the incidence of thrombosis
in ET is lower than in polycythemia vera (PV).
T.Barbui et G.Finazzi, Myeloproliferative disease in
pregnancy and other management issues, ASH 2006 p. 246 -52
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24. Essential thrombocythemia: 2024 update on diagnosis, risk
stratification, and management
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25. NCCN Guidelines Version 3. Myeloproliferative Neoplasms
NCCN Guidelines Version 3. Myeloproliferative Neoplasms
(https://www.nccn.org/professionals/physician_gls/pdf/mpn.pdf). 2022.
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26. Our Study : Treatment
▪25patients:allreceived
▪Antiplatelettherapy:Aspégic®100mg/day
▪Cytoreductivetherapy:Hydroxyurea,30–50mg/kg
▪Theclinicalcoursewaslongandstable,withamedian
overallsurvivalof46months(range:8to170months).
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27. Comments (1)
▪Essential Thrombocythemia is a rare disorder.
▪In our department, we observe an average of 1.6 cases per
year.
▪The incidence in Algeria appears low (0.06 per 100,000),
compared to reported rates of 0.38–1.7 per 100,000,
▪likely due to underdiagnosis related to limited diagnostic
resources and evolving criteria since 2000.
▪We believe the incidence has increased in recent years,
reflecting improved access to healthcare (public and private)
and rapid automated testing, which has led to a high rate of
incidental diagnosis (72%).
▪The age and sex distribution is consistent with the literature,
with a mean age of 59 years and a predominance of females.
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28. Comments (2)
▪The main challenge in ET lies in the availability of reliable diagnostic
tools, such as testing for the JAK2 V617F mutation, which was
performed in only 48% of cases in 2014.
▪The diagnosis of ET is essentially one of exclusion, relying on the
complete blood count, JAK2 mutation testing, and bone marrow
biopsy (BMB) after ruling out other causes of thrombocytosis (2014
criteria).
▪The BMBremains highly valuable in our context and requires
interpretation by experienced hematopathologists.
▪Myelosuppressive therapy with Hydroxyurea (Hydréa®) is not
systematic and is reserved for symptomatic cases or those with
cardiovascular risk factors.
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29. Conclusion
▪This study allowed us to better characterize the clinical and biological features of
Essential Thrombocythemia (ET) observed in our department:
•A low frequency, estimated at 1.6 cases per year
•Female predominance
•A peak incidence at 59 years
•Incidental discovery in 72% of cases
•Systematic use of bone marrow biopsy in 100% of cases
▪Since 2014, our diagnostic capabilities have significantly improved, notably with
the introduction of JAK2 V617F mutation testing, now recognized as a major
molecular marker for confirming myeloproliferative syndromes.
▪These findings highlight the importance of a multidisciplinary approach
and expanded access to molecular tools for the optimal management of patients
with ET.
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30. Thank you for your attention