A 26-year-old woman diagnosed with systemic lupus erythematosus, on treatment with hydroxychloroquine, consults for a feeling of generalized weakness that has progressively developed in the last 15 days. The physical examination reveals cutaneous pallor and the CBC shows Hb 7.4 g/dL, Hct 31%, MCV 108. Which of the following tests will be most useful in deciding the course of action?
It tells us about a patient with a diagnosis of lupus and macrocytic anemia. In the end, all the data are usually given for a reason. The onset of the picture seems relatively rapid and it is also associated with an autoimmune disease, so it seems that they want you to associate it with an autoimmune hemolytic anemia. The low haptoglobin would tell us it is "hemolytic", the coombs test would tell us it is "autoimmune". Vitamin B12, probably the MCV would be higher than 108 and the onset of the clinical picture would be slower. The ANA would not give us anything in relation to the anemia, since it already has a diagnosis. Therefore, correct answer 2. As a note, autoimmune hemolytic anemias are usually slightly macrocytic due to reticulocytosis. Remember to ask for reticulocytes.
Haptoglobin.
Coombs test.
Vitamin B12.
Antinuclear antibodies.
The onset of the picture seems relatively rapid and it is also associated with an autoimmune disease, so it seems that they want you to associate it with an autoimmune hemolytic anemia. The low haptoglobin would tell us it is "hemolytic", the coombs test would tell us it is "autoimmune".
Vitamin B12, probably the MCV would be higher than 108 and the onset of the clinical picture would be slower.
The ANA would not give us anything in relation to the anemia, since it already has a diagnosis.