He continues, “Once you start seeing that MCV approaching the lower end of the normal range, you can confirm it with a test like retic hemoglobin concentration, and then I think it is incumbent upon you to look for the source of blood loss.” According to recommended guidelines, all adult men and postmenopausal women with iron-deficiency anemia require screening for gastrointestinal malignancy. It is also important to note that other medical causes can less commonly be the source of a microcytic anemia, like lead poisoning.10
Dr. Koury recommends getting a hematology consult if there is any clinical confusion about a case or in particularly severe situations.
Diagnosis of Other Types of Anemia
Rheumatologists may also see some patients with a macrocytic anemia due to treatments like methotrexate, which slow the division of the cell and allow more protein accumulation between cell divisions. Dr. Koury notes, “Especially when I see an MCV of 100 or higher, it’s usually the methotrexate, and you can cut back the dosage and get improved red cell production, whereas if you have a heavy inflammatory component, you probably won’t see the response to reduced dosage.” Pernicious anemia, hypothyroidism, alcoholism, liver dysfunction and myelodysplastic syndrome are some other possible causes of a macrocytic anemia.11
Dr. Koury cautions rheumatologists to be aware of the possibility of a specific diagnostic situation in patients on medications that can increase the MCV. “If you have patients on a medication that is going to increase your MCV, and you have them on other medications that can lead them to have occult blood loss, they could develop a normocytic anemia. You might miss iron deficiency, because the microcytosis induced by too little iron is counterbalanced by methotrexate or other medications that induce macrocytosis.”
Hemolytic anemia can occur in patients with SLE or other autoimmune disorders. Hemolysis is associated with normal to elevated mean corpuscular volume, increased unconjugated bilirubin, increased lactate dehydrogenase and decreased haptoglobin levels. Dr. Koury notes, “Once you see a drop in the hematocrit, you probably need to look at the bilirubin—that’s a quick indicator, and you can look at haptoglobin. One of the best indicators is looking at the peripheral blood smear for spherocytes.” He also recommends getting a hematology consult if there is any clinical confusion about a case or in particularly severe situations.
Treatment of Anemia of Inflammation
We still lack good information about the best way to treat anemia of inflammation. It’s not clear in what specific situations iron, transfusions or erythropoietin-stimulating agents should be used. Clinicians may need to vary their therapeutic approach based on the underlying chronic condition, comorbidities and the specific needs of the individual patient.
