بسم الله الرحمن الرحیم

NEONATAL THROMBOCYTOPENIA

NEONATAL THROMBOCYTOPENIA <150,000/microL Term , preterm

The 5th percentile was lower than the standard adult value and decreased with decreasing GA.

100,000 to 150,000/microL  Mild 50,000 to 99,000/microL  Moderate <50,000/microL Severe

In SGA infants: 31% had platelet <150,000/microL 10% (3 In SGA infants: 31% had platelet  <150,000/microL 10% (3.5 % of all) had a recognized cause (DIC,…) with a high mortality rate (65%)

APPROACH TO NEONATAL THROMBOCYTOPENIA

Time of presentation 1- Fetal 2- Early (< 72 h.) 3- Late (< 72 h.)

Fetal : - Mainly TORCH - Alloimmune Condition -Autoimmune condition (e Fetal : - Mainly TORCH - Alloimmune Condition -Autoimmune condition (e.g.,ITP, SLE) - Aneuploidy (Trisomy 13, 18 & 21) - Congenital/Inherited (Wiskoot-Aldrich syn.)

Early-onset neonatal(72h) - Placental insufficiency (IUGR,diabetes) - Perinatal asphyxia - Alloimmune condition -Autoimmune condition (e.g.,ITP, SLE) - Thrombosis( e.g.,renal vein, aortic) - Metabolic disease(proprionic and methylmalonic acidemia) - Bone marrow replacement ( congenital leukemia) - Congenital infection(CMV, Toxo, HIV) - Congenital/inherited (e.g.,TAR, CAMT) - Kasabach-Merritt syndrome

Late-onset neonatal(>72h) - Late-onset sepsis - NEC - Congenital infection (e.g., CMV, toxo, rubella, HIV) - Autoimmune - Kasabach-Merritt syndrome - Metabolic disease(proprionic and methylmalonic acidemia) - Congenital/inherited (e.g.,TAR, CAMT)

Decreased Production: Marrow hypoplasia -viral infections (TORCH,HIV) Bon Marrow Failure - Fanconi’s anemia Idiopathic aplastic anemia Drug-induced Marrow infiltration - Lukemia Familial -macro thrombocytopenia, Alport’s syn

Increaed Consumtion:. Immune Mechanisms:. - ITP. - Alloimmune Increaed Consumtion: Immune Mechanisms: - ITP - Alloimmune - Drug- assosiated Coagulation activation - DIC Mechanical pooling - Hypersplenism Thrombotic microangiopathies -HUS - TTP

History: - Onset - Clinical examination. - Organomegaly History: - Onset - Clinical examination - Organomegaly - Joint or soft tissue bleeding - Ischemic limb, necrosis - Recent transfusion

Drugs and thrombocytopenia: Acetaminophen Amphotericin B Carbamezapine Chlorpropamide Cimetidine Danazol Hydrochlorothiazide Interferon-α Methyldopa Nalidixic Acid Phenytoine Quinidine Ranitidine Rifampin Trimethoprim/sulfamethoxazole Vancomycin

Morphologic aspect of PBS: Large: macrothrombocytopenia Large + Normal size: peripheral distruction Normal size: reduced production Small: Wiskott-Aldrich syn. Variable size: myelodysplastic syn.

Mean platelet volume (MPV) average size of circulating platelets Normal (7.5–9.5 fL): reduced production Elevated (10–12 fL): accelerated destruction

Reticulated platelets: Newly produced platelets having a higher ribonucleic acid content than do older platelets

RP% is low (< 2%): Low platelet production & high(> 10%): platelets are being consumed