At the family medicine center, Sofia, a 32-year-old black person of African descent, came to visit the doctor because she has been feeling fatigue as well as exertional dyspnea.
Her medical history includes systemic lupus erythematosus.
Next to Sofia, a father from Ireland brings his 14-year-old son, John, who’s been less active and has bruised easily for the past month.
John’s medical history includes recurrent upper respiratory tract infections before the onset of the current symptoms.
During the clinical examination, his spleen cannot be palpated.
CBC is ordered for both people and they show low hemoglobin with normal MCV and reticulocyte count index lower than 2%.
John also has leukopenia and thrombocytopenia.
Both John and Sofia are suffering from anemia, which is defined as lower than average levels of hemoglobin, typically below 13.5 grams per deciliterg/dL in adult men and below 12.0 g/dL in adult women.
For children, this level varies based on the age.
Now, anemias can be broadly grouped into 3 categories based on mean corpuscular volume, or MCV, which reflects the volume of an RBC.
So, microcytic anemia is where the MCV is lower than 80 femtolitersfL, normocytic is when, with an the MCV is between 80 and 100 femtolitersfL, and macrocytic is when the, with an MCV is larger than 100 femtolitersfL.
Alright, the normocytic anemias can be further classified as hemolytic where there’s increased destruction of red blood cells and non-hemolytic where there’s decreased production of red blood cells in the bone marrow.
When there’s hemolysis, the bone marrow revs up and starts pumping out reticulocytes which are immature red blood cells, but when there’s a bone marrow problem the reticulocyte count is low.
So for your exams, if you run into a normocytic anemia and the reticulocyte production index, or RPI, is higher than 2%, think hemolytic anemia, since the red blood cells are being destroyed and the body compensates by producing more.
If it’s a non-hemolytic anemia, the reticulocyte production index is lower than 2% since the anemia is caused by a decrease in red blood cell production.
Now, in this video, let’s focus on the nonhemolytic normocytic anemias, which are basically anemia of chronic disease and aplastic anemia.