Is increased red cell distribution width an indicating marker of nonalcoholic steatohepatitis and fibrotic stage?

Abstract

Red cell distribution width (RDW) may play an important role in predicting steatohepatitis and liver fibrosis. In the original study, it was aimed to determine whether RDW could be used for this purpose or not. There are studies indicating that higher RDW is correlated well with components of metabolic syndrome. Because nonalcoholic fatty liver disease is now recognized as the hepatic manifestation of metabolic syndrome, possible impact of the accompanying confounders on the study findings should have been detailed. There may be a patient selection bias due to use of improper cut-off values for alcohol consumption and inclusion of only subjects with normal aminotransferase levels and normal abdominal ultrasonography. Patients without hepatosteatosis on ultrasonography and with any restriction of aminotransferase levels should have been included in the control group, because isolated aminotransferase elevation is not decisive in the diagnosis of hepatosteatosis. Although iron, vitamin B₁₂ and folic acid deficiencies were included in exclusion criteria, functional forms of these molecules like methylmalonic acid, homocysteine, ferritin levels and total iron binding capacity, which are more sensitive and specific parameters for vitamin B₁₂ and folic acid deficiencies, were not mentioned. Consequently, RDW, an inexpensive, non-invasive, but powerful indicator overlooked on whole blood analysis, itself without other inflammatory markers may not accurately provide information about progression of nonalcoholic steatohepatitis and fibrosis.

Keywords: Anemia; Fibrosis; Red cell distribution width; Steatohepatitis; Steatosis

Core tip: Red cell distribution width (RDW) may play an important role in predicting steatohepatitis and stage of liver fibrosis. Use of improper cut-off values for alcohol consumption and inclusion of only subjects with normal aminotransferase levels and normal abdominal ultrasonography may result in a patient selection bias. Instead of using the iron, vitamin B₁₂ and folic acid, use of the functional forms of these molecules like methylmalonic acid, homocysteine, ferritin levels and total iron binding capacity is more sensitive and specific for vitamin B₁₂ and folic acid deficiency. Consequently, RDW itself without other inflammatory markers may not accurately provide information about progression of nonalcoholic steatohepatitis and fibrosis.