🫀 Interná medicína · 34

Trombocytopénia a trombocytóza (definície, príčiny, charakteristika)

Definícia

• Trombocytopénia je u dospelých počet trombocytov pod 150 000/µl; trombocytóza (trombocytémia) je počet trombocytov nad 450 000/µl. Trombocytóza sa delí na primárnu (napr. esenciálna trombocytémia, polycythaemia vera) a sekundárnu (reaktívnu), ktorá tvorí približne 80–90 % prípadov.

Etiológia a patogenéza

• Znížená tvorba: napr. zlyhanie kostnej drene (aplastická anémia, PNH), lieky a rádioterapia (napr. kyselina valproová, daptomycín, niektoré chemoterapeutiká), chronické užívanie alkoholu, dedičné trombocytopénie, deficit folátu alebo vitamínu B12, sepsa, vírusové infekcie a myelodysplastické syndrómy.
• Imunitná deštrukcia: napr. primárna ITP, liekmi indukovaná ITP (napr. chinín, sulfónamidy, vankomycín, piperacilín, inhibítory GP IIb/IIIa), lymfoproliferatívne ochorenia, autoimunitné ochorenia (napr. SLE) a chronické infekcie (hepatitída C, HIV, Helicobacter pylori); osobitnou jednotkou je heparínom indukovaná trombocytopénia (HIT).
• Neimunitná spotreba (napr. mechanické chlopne, preeklampsia/HELLP, DIK, trombotická mikroangiopatia), dilúcia (rozsiahla infúzna liečba alebo transfúzia) a sekvestrácia trombocytov v zväčšenej slezine (napr. pri cirhóze).
• Sekundárna trombocytóza vzniká často pri infekcii, zápale, deficite železa, malignite, asplénii, hemolýze, po liekoch alebo pri fyziologickom strese; esenciálna trombocytémia je myeloproliferatívna neoplázia – približne 85–90 % pacientov nesie jednu z driver mutácií JAK2, CALR alebo MPL.

Klinický obraz

• Ľahká trombocytopénia (100 000–150 000/µl) je zvyčajne asymptomatická, stredne ťažká (50 000–100 000/µl) sa môže prejaviť napr. ľahkou tvorbou modrín, ťažká (< 50 000/µl) môže viesť ku krvácaniu pri chirurgických výkonoch; pri počte < 10 000/µl sú pacienti náchylnejší na spontánne krvácanie.
• Krvácanie pri trombocytopénii sa typicky prejavuje petéchiami, nehmatnou purpurou a ekchymózami; orálna purpura a makroskopická hematúria si zaslúžia osobitnú pozornosť, lebo môžu predchádzať ťažkému krvácaniu pri ITP.
• Trombocytopénia môže sprevádzať trombózy – napr. pri HIT, antifosfolipidovom syndróme, DIK, trombotickej mikroangiopatii a PNH; HIT sa typicky objaví 5–14 dní po začatí liečby heparínom (môže aj po jeho vysadení) a spravidla nie je spojená s krvácaním.
• Trombocytóza sa často zistí náhodne pri rutinnom laboratórnom vyšetrení a sama zriedka spôsobuje príznaky; esenciálna trombocytémia sa môže prejaviť napr. trombózou, TIA, erytromelalgiou alebo ľahkou tvorbou modrín.

Diagnostika

• Izolovaná trombocytopénia: KO, náter periférnej krvi a vyšetrenie na HIV a HCV; opakovaný KO potvrdí trombocytopéniu a vylúči laboratórnu chybu.
• Pseudotrombocytopénia vzniká napr. zhlukovaním trombocytov pri EDTA ako antikoagulačnom činidle; schistocyty v nátere sú charakteristické pre trombotickú mikroangiopatiu.
• Pri podozrení na HIT ASH 2018 odporúča odhadnúť pravdepodobnosť 4T skóre (0–3 body: HIT nepravdepodobná); pozitívny PF4 ELISA test treba potvrdiť testom uvoľňovania serotonínu (SRA), ktorý je zlatým štandardom.
• Biopsia kostnej drene je potrebná, ak etiológia trombocytopénie zostáva nejasná alebo je podozrenie na hematologické ochorenie; pri trombocytóze sekundárnu od primárnej odlišuje napr. anamnéza, KO, náter, zápalové markery a vyšetrenie železa.

Liečba

• Asymptomatická ľahká trombocytopénia: opakovaný KO a sledovanie; urgentné stavy (napr. HIT, TTP, HUS, liekmi indukovaná ITP, ťažká trombocytopénia v gravidite alebo s krvácaním) vyžadujú okamžitý postup zameraný na príčinu; pri liekmi indukovanej trombocytopénii vysadenie lieku.
• Primárna ITP u dospelých vyžadujúca úvodnú liečbu (ASH 2026): navrhuje sa rituximab + kortikosteroidy (± IVIG) alebo trombopoetický liek + kortikosteroidy (± IVIG); ak rituximab ani trombopoetické lieky nie sú dostupné, kortikosteroidy (± IVIG) samotné.
• HIT (ASH 2018): vysadiť heparín a začať neheparínové antikoagulans (napr. argatroban, bivalirudín, danaparoid, fondaparinux, DOAC); u pacientov s priemerným rizikom krvácania sa rutinná transfúzia trombocytov nenavrhuje (podmienené odporúčanie).
• Sekundárna trombocytóza ustúpi po liečbe príčiny a antiagreganciá sa pri nej spravidla neindikujú; pri esenciálnej trombocytémii s vysokým rizikom sa spravidla uprednostňuje nízkodávkový aspirín a cytoredukčná liečba (najčastejšie hydroxyurea); aspirínu sa treba vyhnúť pri abnormálnych parametroch von Willebrandovho faktora alebo krvácaní.

Komplikácie a prognóza

• Ťažká trombocytopénia môže viesť k život ohrozujúcemu vnútornému krvácaniu; postihnutie mozgu môže byť fatálne.
• HIT vyvoláva výrazný hyperkoagulačný stav – až u 50 % pacientov vzniknú tromboembolické komplikácie (najčastejšie HVT, pľúcna embólia alebo nekróza kože) s mortalitou až 30 %.
• TTP spôsobuje rozsiahle mikrovaskulárne trombózy (najčastejšie je postihnutý CNS), HUS poškodzuje najmä obličky; bez liečby môžu progredovať do multiorgánového zlyhania.
• Primárna trombocytóza (napr. esenciálna trombocytémia, polycythaemia vera) nesie vyššie riziko trombózy aj krvácania ako sekundárna; po splenektómii je riziko trombózy v prvých týždňoch až 5 %.

Kľúčové pojmy

trombocytopénia	thrombocytopenia
trombocytóza	thrombocytosis
imunitná trombocytopénia (ITP)
heparínom indukovaná trombocytopénia (HIT)
esenciálna trombocytémia	thrombocythaemia essentialis
pseudotrombocytopénia
trombotická trombocytopenická purpura
petéchie	petechiae

📎 Zdroje:

Thrombocytopenia - StatPearls - NCBI Bookshelf (Introduction – definícia)Thrombocytopenia is characterized by a platelet count that falls below the established normal threshold, specifically 150,000/µL in adults.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Introduction – definícia trombocytózy)Thrombocytosis, or thrombocythemia, occurs when the platelet count exceeds 450,000/μL of blood.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Introduction – klasifikácia)Thrombocytosis can be classified as primary or secondary (reactive).
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Introduction – primárna trombocytóza)Primary thrombocytosis, especially in conditions (eg, essential thrombocythemia and polycythemia vera), carries an increased risk of thrombosis and bleeding compared to secondary thrombocytosis.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Epidemiology – podiel sekundárnej)Approximately 80% to 90% of individuals with thrombocytosis have secondary thrombocytosis.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – zlyhanie drene)Thrombocytopenia can result from decreased platelet production due to bone marrow failure, as seen in aplastic anemia and paroxysmal nocturnal hemoglobinuria.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – lieky)Certain drugs, including valproic acid, daptomycin, select chemotherapy agents, and radiation therapy, can suppress bone marrow function. Chronic alcohol use and inherited thrombocytopenias also impair platelet production.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – systémové stavy)Viral infections and systemic conditions, eg, nutritional deficiencies in folate or vitamin B12, sepsis, and myelodysplastic syndromes further compromise marrow function.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – imunitná deštrukcia)These antibodies can arise in primary ITP, drug-induced ITP, lymphoproliferative disorders, autoimmune diseases (eg, SLE), and chronic infections, including hepatitis C, HIV, and Helicobacter pylori.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Etiology – liekmi indukovaná ITP)Drug-induced ITP includes reactions to medications, eg, quinine, sulfonamides, ampicillin, vancomycin, piperacillin, acetaminophen, ibuprofen, naproxen, cimetidine, and glycoprotein IIb/IIIa inhibitors.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Etiology – HIT)HIT involves antiplatelet antibodies that activate platelets, resulting in arterial and venous thrombosis.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – neimunitná deštrukcia)Nonimmune platelet destruction occurs in patients with mechanical heart valves, preeclampsia or HELLP syndrome, DIC, and thrombotic microangiopathy, where platelet consumption and thrombus formation drive thrombocytopenia.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – dilúcia)Extensive fluid resuscitation or blood transfusion can lead to dilutional thrombocytopenia.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – redistribúcia)Conditions that cause splenomegaly, eg, splenic congestion from cirrhosis, can sequester platelets, thereby reducing the number of circulating platelets and contributing to thrombocytopenia.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Introduction – príčiny reaktívnej trombocytózy)Representing approximately 80% to 90% of thrombocytosis cases, reactive thrombocytosis commonly results from infection, inflammation, iron deficiency, malignancy, asplenia, hemolysis, medication exposure, or physiologic stress.
Essential Thrombocytosis - StatPearls - NCBI Bookshelf (Pathophysiology – driver gény)The driver genes JAK2, CALR, and MPL have specific physiological functions that, when mutated, lead to MPNs.
Essential Thrombocytosis - StatPearls - NCBI Bookshelf (Pathophysiology – podiel driver mutácií)Approximately 85% to 90% of patients with ET carry 1 of these driver mutations, underscoring the diagnostic significance of molecular testing.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Introduction – ľahká a stredne ťažká)Mild thrombocytopenia (100,000-150,000/µL) is generally asymptomatic. Moderate thrombocytopenia (50,000-100,000/µL) may manifest symptoms, eg, easy bruising.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Introduction – ťažká)Severe thrombocytopenia (below 50,000/µL) can lead to bleeding during surgical procedures, and individuals with platelet counts under 10,000/µL are more susceptible to spontaneous hemorrhage.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Physical Examination – prejavy krvácania)Thrombocytopenia-related bleeding typically presents as petechiae, non-palpable purpura, and ecchymosis.
Thrombocytopenia - StatPearls - NCBI Bookshelf (History and Physical – varovné príznaky)Oral purpura and gross hematuria warrant special attention, as they may precede severe hemorrhage associated with ITP
Thrombocytopenia - StatPearls - NCBI Bookshelf (Introduction – trombocytopénia s trombózou)Additionally, thrombocytopenia may coexist with thrombotic events in conditions including heparin-induced thrombocytopenia (HIT), antiphospholipid antibody syndrome (APS), disseminated intravascular coagulation (DIC), thrombotic microangiopathy, and paroxysmal nocturnal hemoglobinuria (PNH).
Heparin-Induced Thrombocytopenia - StatPearls - NCBI Bookshelf (Enhancing Healthcare Team Outcomes – nástup HIT)The onset of HIT typically occurs 5-14 days after the start of heparin therapy, and it may also occur after heparin cessation.
Heparin-Induced Thrombocytopenia - StatPearls - NCBI Bookshelf (History and Physical – krvácanie)HIT is generally not associated with bleeding.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Enhancing Healthcare Team Outcomes – náhodný nález)Although the elevated platelet count is often discovered incidentally during routine laboratory testing and rarely causes symptoms directly, identification and treatment of the underlying cause remain essential.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Evaluation – izolovaná trombocytopénia)Evaluation of patients with isolated thrombocytopenia begins with a complete blood count (CBC), peripheral blood smear, and testing for HIV and hepatitis C virus. A repeat CBC helps confirm thrombocytopenia and rule out laboratory error.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Histopathology – pseudotrombocytopénia)Platelet clumping can occur when EDTA is used as an anticoagulant, resulting in pseudothrombocytopenia.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Histopathology – schistocyty)Schistocytes, or fragmented RBCs, are characteristic of thrombotic microangiopathic conditions and reflect intravascular hemolysis
American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia (Blood Adv, PMC6258919) (Recommendation 2.1 – 4Ts skóre)In patients with suspected HIT, the ASH guideline panel recommends using the 4Ts score to estimate the probability of HIT rather than a gestalt approach.
Heparin-Induced Thrombocytopenia - StatPearls - NCBI Bookshelf (Evaluation – nízke 4T skóre)A 4T score of 0 to 3 points means HIT is unlikely
Heparin-Induced Thrombocytopenia - StatPearls - NCBI Bookshelf (Evaluation – PF4 ELISA a SRA)Thus, if the PF4 ELISA is positive, the result should be confirmed with the SRA, the gold standard test for confirming HIT with high sensitivity and specificity.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Evaluation – biopsia drene)A bone marrow biopsy becomes necessary when the etiology of thrombocytopenia remains unclear or a hematologic disorder is suspected.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Enhancing Healthcare Team Outcomes – diagnostika trombocytózy)Diagnostic assessment includes a focused history, physical examination, complete blood count, peripheral smear, inflammatory markers, and iron studies to distinguish secondary from primary thrombocytosis.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Treatment / Management – ľahká trombocytopénia)In patients with asymptomatic, mild thrombocytopenia, repeat CBC and routine monitoring is the recommended management.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Treatment / Management – urgentné stavy)However, thrombocytopenia emergencies that require immediate action include HIT, TTP, HUS, drug-induced ITP, pregnancy with severe thrombocytopenia, bleeding with severe thrombocytopenia
Thrombocytopenia - StatPearls - NCBI Bookshelf (Treatment / Management – liekmi indukovaná)Discontinuation of the offending drug typically leads to recovery of platelet counts in cases of drug-induced thrombocytopenia.
American Society of Hematology 2019 guidelines for immune thrombocytopenia (Blood Adv, PMC6963252) (Recommendation 1b – dospelí, novodiagnostikovaná ITP, trombocyty ≥ 30 × 10⁹/L)who are asymptomatic or have minor mucocutaneous bleeding, the ASH guideline panel recommends against corticosteroids and in favor of management with observation (strong recommendation
American Society of Hematology 2019 guidelines for immune thrombocytopenia (Blood Adv, PMC6963252) (Recommendation 2 – dĺžka liečby prednizónom)In adults with newly diagnosed ITP, the ASH guideline panel recommends against a prolonged course (>6 weeks including treatment and taper) of prednisone and in favor of a short course (≤6 weeks)
American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia (Blood Adv, PMC6258919) (Recommendation 3.1)In patients with HITT or acute HIT without thrombosis (isolated HIT), the ASH guideline panel recommends discontinuation of heparin and initiation of a non-heparin anticoagulant (strong recommendation
American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia (Blood Adv, PMC6258919) (Summary – voľba antikoagulancia)Conditional recommendations include the choice among non-heparin anticoagulants (argatroban, bivalirudin, danaparoid, fondaparinux, direct oral anticoagulants) for treatment of acute HIT.
American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia (Blood Adv, PMC6258919) (Recommendation 3.6 – transfúzia trombocytov)In patients with acute HITT or acute isolated HIT who are at average risk of bleeding, the ASH guideline panel suggests against routine platelet transfusion (conditional recommendation
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Treatment / Management – sekundárna trombocytóza)Secondary thrombocytosis resolves with treatment of the underlying etiology.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Treatment / Management – antiagreganciá)Antiplatelet treatments, eg, aspirin and P2Y12 receptor inhibitors, are generally not indicated for secondary thrombocytosis because of the very low risk of thrombosis.
Essential Thrombocytosis - StatPearls - NCBI Bookshelf (Treatment / Management – vysoké riziko)For high-risk individuals, antiplatelet (low-dose aspirin) and cytoreductive therapy are preferred treatments.
Essential Thrombocytosis - StatPearls - NCBI Bookshelf (Treatment / Management – hydroxyurea)Hydroxyurea is the most commonly used cytoreductive agent, with anagrelide and pegylated interferon used secondarily.
Essential Thrombocytosis - StatPearls - NCBI Bookshelf (Treatment / Management – kontraindikácia aspirínu)Aspirin should be avoided if abnormal von Willebrand laboratory parameters and/or bleeding are present.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Complications – krvácanie)Severe thrombocytopenia can result in life-threatening internal bleeding, and involvement of the brain may lead to fatal outcomes.
Heparin-Induced Thrombocytopenia - StatPearls - NCBI Bookshelf (Pathophysiology – tromboembolické komplikácie)HIT causes an extremely hypercoagulable state, where up to 50% of patients develop thromboembolic complications, associated with a mortality rate of up to 30%.
Heparin-Induced Thrombocytopenia - StatPearls - NCBI Bookshelf (Complications – typy trombóz)The most common complications are deep venous thrombosis (DVT), pulmonary embolism (PE), or skin necrosis.
Thrombocytopenia - StatPearls - NCBI Bookshelf (Complications – TTP a HUS)TTP causes widespread microvascular thrombosis affecting multiple organs, with the central nervous system most commonly involved. HUS predominantly damages the kidneys, although both TTP and HUS can advance to multiorgan failure when untreated.
Secondary Thrombocytosis - StatPearls - NCBI Bookshelf (Pathophysiology – splenektómia)The risk of thrombosis is as high as 5% in the few weeks following splenectomy
ASH 2026 ITP Guidelines – Summary of Changes (27. 8. 2026), odporúčanie 1Suggests either rituximab plus corticosteroids (±IVIG) or a thrombopoietic agent plus corticosteroids (±IVIG) rather than MMF plus corticosteroids (±IVIG) or
ASH 2026 ITP Guidelines – Summary of Changes (27. 8. 2026), odporúčanie 1If rituximab and thrombopoietic agents are not available, suggests corticosteroids (±IVIG) alone over MMF plus corticosteroids (±IVIG).
Essential Thrombocytosis - StatPearls - NCBI Bookshelf (History and Physical – prejavy ET)Patients can also present with various manifestations of thrombosis
Essential Thrombocytosis - StatPearls - NCBI Bookshelf (History and Physical – prejavy ET)or with transient ischemic attack, erythromelalgia, and easy bruising

Precvičiť tému (6)

Kartičky

Rozdeľte príčiny trombocytopénie podľa mechanizmu a uveďte príklady.

Najprv si odpoveď povedz nahlas alebo v duchu – až potom ju odkry.

Aké sú klinické prejavy trombocytopénie v závislosti od počtu trombocytov?

Najprv si odpoveď povedz nahlas alebo v duchu – až potom ju odkry.

Ako postupujete pri podozrení na heparínom indukovanú trombocytopéniu?

Najprv si odpoveď povedz nahlas alebo v duchu – až potom ju odkry.