Diseases Involving Blood Platelets

By Suparn Kelkar Roll no 25 3rd 2nd

Functions of Platelets

Primary Arrest of bleeding Participate in blood clotting mechanism

Overview of Diseases involving Platelets Purpura1) Nonthrombocytopenic purpura2) Thrombocytopenic purpurai. Primaryii. Secondary Thrombotic Thrombocytopenic Purpura Wiskott-Aldrich Syndrome Familial Thrombasthenia Thrombocytopathic Purpura Thrombocythemia

Purpura

It is defined as a purplish discoloration of the skin and mucous membrane due to spontaneous extravasation of blood and is itself a symptom rather than a disease entity

ThrombocytastheniaIt is the term used to designate a variety of diseases characterized by a Qualitative defect in blood

Nonthrombocytopenic PurpuraPurpura due to alteration in capillariesCausesA. AutoimmuneB. InfectionsC. Structural Malformations

D Miscellaneous

Oral ManifestationsResemble thrombocytopenic purpura

Thrombocytopenic PurpuraThis is a disease in which there is a abnormal

reduction in the NUMBER of circulating Platelets

Causes focal hemmorhage into various tissues and organs including skin and mucous membrane

2 typesi. Primary or essentialii. Secondary or symptomatic purpura

Primary Thrombocytopenia

Autoimmune disorderAntibodies are produced againsts patients

own plateletsCauses decrease in platelet count due to:1. Antiplatelet Globulin2. Absence of platelet stimulating/

megakaryocyte ripening factor Acute form-----affects children Chronic form----affects mostly female and

adults

Secondary ThrombocytopeniaEtiologyI. Conditions associated with REDUCTION

of platelet count

Infiltration of Marrow by abnormal cellsMegaloblastic Anemia Metabolic disorders

InfectionBacterial :Spirochetal :RickettsialViral :

II.Conditions associated with a reduction in LIFESPAN of Platelets

Diseases Related to Mechanism

Diseases Resulting in platelet utilization at an increased rate

III. Thrombocytopenia due to DILUTION of platelet by transfusion of platelet poor blood

IV. Conditions in which thrombocytopenia is of IDIOPATHIC PATHOGENESIS

Clinical Features1) Age: 10-30 yrs, no sexual predilection 2) Characteristics Spontaneous appearance of purpuric or

hemorrhagic lesions of skin These vary in size From tiny red pinpoint petechiae to large

purplish ecchymoses to massive hematoma

Pt feels burning sensation in these areasEpistaxis i.e. bleeding from nose, urinary

tract bleeding causing hematuria , bleeding in GIT causing melenema or hematemesi

Spleen is not palpable***If palpable the it is due to LEUKEMIA

Oral Manifestations1. Severe or Often Profuse GINGIVAL

hemmorhage

Petechiae on oral mucosa , commonly on palate seen as tiny grouped clustures 1mm or less in diameter

Sometimes Ecchymoses occur

Laboratory findingsPlatelet count : below 60,000 per cu mmBleeding time : 1hr or moreClotting time : normalRBC and WBC count : normalIf giant platelets present on peripheral blood

smear then ---- it is CONGENITAL thrombocytopenia

Treatment and PrognosisNo specific treatmentSplenectomy can be doneFor symptomatic releif -- blood transfusion and bed restDrugs : Corticosteroids therapy bt may relapse In secondary thrombocytopenia: correction or removal of etiologic factors is essential Death occurs due to sudden severe hemorrhagePrognosis is GOOD

Thrombotic Thrombocytopenic Purpura (TTP)Also known as Moschcowitz diseaseUncommon form of Thrombocytopenic

purpuraIt is a life threatening multisystem disorder of

an obscure nature but may be immunologically mediated

Described by Eli Moschowitz in 1924

EitiologyHIV ,Cancer ,Bacterial infection, Bone marrow

Transplantation and other drugs

Mechanism of ActionMicroangiopathic hemolysis and platelet

aggregration/Hyline thrombi in microcirculationThrombi -- Occlude vascular lumiaEndothelia of BRAIN and KIDNEYS are most

affected

No inflammatory response is seenBut fragments of erythrocytes and hemolysis

is seen in blood

CLINICAL FEATURES1. Age : Young Adults2. Sex : Females more commonly affected3. Thrombocytopenia4. Hemolytic anemia5. Fever6. Transitory neurologic dysfunction7. Renal failure

Histologic FeaturesWidespread microthrombi in blood vessels

such as Arteriole, Venules, and Capillaries

Gingival tissue show subintemal deposits of PAS stain at Arteriocapillary junction

Laboratory Findingsdecreased platelet count, Hb is decreasedFragmented RBC’s (schistocytes)Reticulocyte count IncreasedProthrombin time : NormaLactivated platelet thromboplastin time (aPTT) :

NormalLDH levels increasedIndirect Bilirubin levels increasedUrine Examination :Proteinuria + Hematuria seen

Treatment and PrognosisBut now modern therapeutics drugs and

techniques such as

Corticosteroids, Platelet aggregation inhibitors, Splenectomy, And exchange transfusions provide treatment options

Wiskott-Aldrich SyndromeAlso known as Hypogammaglbinemia MThis is a X-linked recessive genetic condition

with variable expression, commonly include immunoglobulin M (IgM) deficiency

Severe congenital immunodeficiency

Clinical FeaturesSex : Exclusive to MalesCharacterized by thrombocytopenia purpura,

eczema on face

Petechiae and purplish rash or ecchymoses of the skin

Eczema is allergic in nature Pt commonly manifests1. Boils2. Otitis Media3. Bloody diarrhea4. And respiratory infection Imp Features1. Occurance of LYMPHOETICULAR MALIGNANT

NEPLASIAS2. Malignant lymphoma (most common)

ORAl manifestationsSpontaneous gingival bleeding and palatal

petechiae seen

Laboratory FindingsThrombocyte count : 18,000-80,000 per cu

mm of bloodBleeding time : IncreasedAnisocytosis i.e. change in SIZE and SHAPE of

platelets : Platelets are usually Smaller in size

Qualitatively : Production and Maturation of immature platelets is decreased overall

Treatment and Prognosis No specific treatmentAntibiotics and Platelet transfusions, bone

marrow transplantation are available treatment options

Overall Prognosis is POORDeath occurs due to secondary infection or

severe hemorrhage within 1st 5 yrs of life

Familial ThrombastheniaCommonly known as Glanzmann

thrombasthenia or diseaseIt is a hereditary, chronic hemorrhagic disease

transmitted as an autosomal recessive trait

Clinical FeaturesSex : Both genders affectedBut in females onset of menarche can cause

this disorderPatients exhibit excessive bleeding eighter

spontaneously or following minor traumaPurpuric hemorrhages of skinEpistaxis and GIT bleedingHemarthrosis seen in some cases

Oral manifestations : spontaneous gingival bleeding, palatal petechiae

Laboratory findings1. Bleeding time : Prolonged2. Cloth retraction is impaired3. Clotting time : Normal4. Platelet count : Normal5. Reduced amounts of membrane

glygoprotiens on surface of platelet

TreatmentNo specific treatmentMicrofibrillar collagen preparations with

fibrinolytic inhibitor, c-aminocarproic acid are employed to control postoperative hemorrhage

Thrombocytopathic PurpuraAlso known as thrombocytopathiaThese are a group of rare diseases with

unnown eitiology in which patients manifest a bleeding tendancy referable to qualitative efects in blood platelets

Platelet count remains normal, therefore is different from thrombocytopenia

Clinical featuresPatients have Severe bleeding tendency and

Bruise easily after minor traumaSpontaneous Ecchymoses seenEpistaxis and bleeding into GIT are a common

findingIn females menstrual bleeding becomes so

severe that blood transfusions may be required

Oral Manifestations1. Spontaneous gingival bleeding2. Mucosal ecchymoses

Laboratory FindingsPlatelet count : normalBleeding time : normal or prolongedBernard-Soulier syndrome : abnormal

response to fibrinogen

TreatmentNo specific treatment availablePriority of treatment is symptomatic control

i.e control of severe hemorrhageDeath is rare but has occurred in a few cases

ThrombocythemiaAlso known as thrombocytosis or increase in number

of platelet count2 forms are recognisedi. Primary (essential)ii. Secondary Eitiologyi. Primary : Unknownii. Secondary : Traumatic injury, inflammatory

responses, surgery , parturition, polycythemia , myeloid luekemia, anemia, tuberculosis, sarcoidosis, hyperadrenalism, rheumatoid arthritis, bronchial carcinoma with osseous metastases

Mechanism of ActionIn secondary thrombocytosis there is overproduction of

proinflammatory CYTOKINES such asi. IL-1ii. IL-6iii. IL-11 Along with C-reactive protein, G-CSF , GM-CSF All these factors together lead to increase in platelet

count when there is i. Chronic inflammationii. Infectioniii. Malignancies

Cinical FeaturesNo gender or age predilection is seenHemorrhage found on skinEpitaxis and bleeding into GIT and nervous

systemFew patients remain asymptomatic and are

identified on routine blood count

Oral manifestationsSpontaneous gingival bleeding is commonPetechiae are rare***Excessive and prolonged bleeding after dental

extraction

Laboratory findingsPlatelet count : greatly increased, i.e. could be

as high as 1,40,00,000 per cu mmAbnormal platelet aggregrationBleeding time: ProlongedClotting time: normalProthrombin time: normalClot Retraction :normalIn secondary thrombocythemia RBC and WBC

counts are abnormal

TreatmentAdministration of Radioactive Phosphorus

(P32)Blood transfusions in cases of severe

hemorrhageDrugs : Aspirin, Heparin (in cases of

thrombotic episodes) , Corticosteroids are administered

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