Acquired Hemolytic Anemias DR. Sana D. Jalal

Immune Hemolytic anemia Autoimmune Alloimmune Drugs Hemolytic Transfusion reaction Hemolytic Disease of the Newborn Warm Cold

Etiology of Warm AIHA Idiopathic : (in about one third of cases) 2. Secondary: in association with other disorders including autoimmune disorders, lymphomas and some drugs like aldomet. auto-antibody best reacts with red cells at 37C, IgG class, usually associated with extravascular hemolysis.

Clinical Features of Warm AIHA Usually with insidious onset of pallor and jaundice with splenomegaly . Signs and symptoms of SLE, lymphoma or history of drug intake due to hypertension.(secondary cases).

Blood Picture in warm AIHA Variable anemia, normochromic, spherocytes and micro-spherocytes with polychromasia

Most important is the Direct Coomb’s Test, and if positive, it is of diagnostic value.

Cold Autoimmune HA Cold AIHA may be 1. Idiopathic. 2. Secondary : in association with lymphomas and certain infections like Mycoplasma pneumoniae. autoantibody reacts best with RBC in the cold at 4C, IgM class, with the capacity to intravascular lysis.

Clinical Features of cold AIHA: In most idiopathic cases the patients have persistent pallor with or without jaundice. Alternatively patients may have episodes of hemoglobinuria, induced by chilling or a combination of these two patterns may also occur. Cold mediated vaso-occlusion phenomena like acrocyanosis may be encountered. Splenomegaly is commonly encountered.

Blood film in cold AIHA Direct Coomb’s test is classically positive. Detection of significant cold antibodies by the cold agglutinin titre tests.

Aplastic Anemia

Definition Pancytopenia in the blood and a hypocellular marrow in which normal haemopoietic elements are replaced by fat cells. Abnormal cells are not present in the peripheral blood or bone marrow.

Etiology Idiopathic Drugs related Irradiation Infective agents a.Cytotoxic drugs. b.Other drugs Chloramph-enicol, Benzene, sulphonamide > 2/3 of cases Hepatitis, HIV, EBVirus etc.

Clinical Manifestations 1.Bleeding tendency, Purpura , mucous membrane bleeding, e,g epistaxis, GI blood loss , bleeding per vagina. 2. Tiredness. 3. Infections. 4. No jaundice. 5. No organomegaly.

Blood Picture Pancytopenia ( reduction in Red cells (HB), WBC, and Platelets). CBP Findings : Red cells : normochromic, usually macrocytic, with reduced retics. Red cell indices : MCV usually increased, MCH and MCHC usually normal.

Bone Marrow Findings

Anemia of Chronic Disease Chronic infection, inflammation or malignancy TB, lung abscess, HIV RA, SLE, or other autoimmune dz Malignancy Release of inflammatory cytokines suppresses erythropoiesis Hallmarks—low serum iron, low TIBC/transferrin, normal/increased ferritin . Dosage — EPO is given in a starting dose of 100 to 150 U/kg subcutaneously three times weekly along with supplemental oral iron. Responders may show a rise in the hemoglobin concentration of at least 0.5 g/dL by two to four weeks …If there is no elevation in the hemoglobin concentration by six to eight weeks, the regimen can be intensified to daily therapy or 300 U/kg three times weekly. It is not worthwhile to continue EPO in patients who do not have a clinically meaningful response by 12 weeks However, most clinicians use 30,000 to 40,000 U of EPO given SQ once per week, a single dose which is numerically equivalent to a dose of 140 to 190 U/kg three times per week for a 70 kg person [66,67]. This dose can be increased to 60,000 U if there is no response (ie, hemoglobin rise <1 g/dL) at four weeks. Darbepoetin was approved by the FDA on July 19, 2002 for the treatment of chemotherapy-induced anemia in nonmyeloid malignancies. The suggested initial dose for this indication is 2.25 µg/kg SQ once per week, which is different from the initial dose suggested for correction of anemia in chronic renal failure (0.45 µg/kg SQ or IV once per week).