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The Haemolytic Anaemias Presenting Complaint Symptoms & Signs Anaemia: tiredness, unwellness, pale conjunctiva, tachycardia, tachypnoea, hypotension; asymptomatic. Sudden onset: angina, weakness, shortness of breath. Bilirubin stones develop?gallstone symptoms Haemoglobinuria causes dark urine, seen in intravascular haemolysis Exogenous factors: penicillin, L-DOPA, fava beans and henna in G6PD deficiency Splenomegaly Signs and symptoms of underlying disease: sickle cell anaemia, CLL, SLE etc. They may be unwell if this is precipitated by infection Bilirubinaemia?jaundice, scleral icterus Bleeding and petechiae if there is TTP causing MAHA
Investigations Low RBCs ? high LDH in blood and High unconjugated bilirubin MCV is normal or high (due to reticulocytes) Platelets will be down in MAHA (due to DIC, TTP, HUS, prosthetic valves), maybe SLE and CLL. Coombs' test: the direct Coombs' test shows that a haemolytic anaemia is autoimmune. It is positive when there are anti-RBC antibodies; antihuman globulins attack them and cause clumping, so here there is agglutination visibly seen. It is also known as the direct antiglobulin test or DAT. Warm IgG antibodies react at 37degreesC whereas the IgM cold antibodies react at 20degreesC or below. Blood film: may show spherocytes in hereditary spherocytosis; may show schistocytes (RBC fragments) in all causes of MAHA; shows sickle cells; excludes malaria as well; echinocytes in pyruvate kinase deficiency; shows reticulocytes if this is chronic and there is a compensatory reticulocytosis. Genetic causes: enzyme assays and osmotic testing for fragile RBCs
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