Anemia Flashcards
What test is used to diagnose Warm Autoimmune Hemolytic Anemia and what antibodies are responsible? Is complement involved?
The direct Coombs (antiglobulin) test is used to diagnose WAIHA and is typically positive for IgG and negative or only weakly positive for complement (C3).
What is the management of Warm Autoimmune Hemolytic Anemia?
Steroids with prolonged taper. Splenctomy consider in nonresponders and those with relapse. Other options include rituximab or other immunosuppressants may be used.
What test is used to diagnose Cold Autoimmune Hemolytic Anemia and what antibodies are responsible? Is complement involved?
Caused by binding of IgM antibodies with complement fixation and intravascular descruction or in the liver. Maximal activity seen at 4 degrees C. Negative coombs test with agglutination seen on peripheral smear.
What is the management of Cold Autoimmune Hemolytic Anemia?
Avoidance of cold temperatures and clothing to proctect the extremities. Immunosuppressives including ritaximab can be considered.
What are the most common drugs that cause Drug-induced Hemolytic Anemia and how soon is the presentation noted after starting the drug?
Usually 2nd and 3rd generation cephalosporins though many others may cause it. The presentation is usually days to weeks after starting the drug.
What are the laboratory findings is Microangiopathic Hemolytic Anemia?
Low haptoglobin, hemoglobinuria, and elevated LDH.
What is the differential for MAHA?
Thrombotic thrombocytopenic purpura Hemolytic uremic syndrome Disseminated intravascular coagulation Intravascular foreign devices HELLP syndrome Preeclampsia Malignant hypertension Severe vasculitis Scleroderma renal crisis Catastrophic antibody syndrome Malignancy Drugs Bone marrow and solid organ transplantation
What is the pathogenesis of Paroxysmal nocturnal hemoglobinuria?
It is an acquired disorder caused by mutations in the PIG-A gene lead to the reduction or absence of glycosylphosphatidylinositol, an important erythrocyte-anchoring protein. Hemolysis is caused by the absence of decay-accelerating factor (CD55) and the membrane inhibitor of reactive lysis (CD59), which are glycosylphosphatidylinositol-dependent complement regulatory proteins.
How is Paroxysmal nocturnal hemoglobinuria diagnosed and what is the treatment?
Diagnosis of PNH is based on flow cytometry results, which can detect CD55 and CD59 deficiency on the surface of peripheral erythrocytes or leukocytes. Anticoagulation should be given to those with thrombotic complications or high deficiency levels. Eculizumab, a humanized monoclonal antibody against the C5 terminal complement component, has also been shown to decrease need for transfusion and improve qualitiy of life. Meningicoccal vaccine must be given prior to this. Can consider BMT, steroids
What are some of the signs of Paroxysmal nocturnal hemoglobinuria?
Hemolytic anemia, pancytopenia, or unprovoked atypical thrombosis.
How does hepcidin work?
Hepcidin production is increased in inflammatory conditions through IL-6. Hepcidin works by decreasing iron absorption from the gut and inhibiting iron release from macrophages by causing internalization and proteolysis of the iron transporter ferroportin.
What is the most common pathway affected in hemochromatosis?
it is autosomal recessive. The most common abnormality found in patients with hemochromatosis involves the HFE gene, the gene product of which interacts with the transferrin receptor, bone morphogenic protein, and SMAD proteins to regulate hepcidin production.
What effects are most commonly seen in hemochromatosis?
Heart, liver complications. Diabetes, endocrinopathys, arthopathy, bronzing of the skin.
How do you diagnose hemochromatosis?
Serum transferrin satuation is the most sensitive test with levels greater than 60% for men and 50% for women. Elevated ferritin can also be suggestive. Confirmation is via liver biopsy. Positive genetic testing is also confirmatory.
