• Other disorders which cause macrocytosis without DNA replication problems (i.e., non-megaloblastic macrocytic anemias), are disorders associated with increased red cell membrane surface area, such as pathologies of the liver and spleen which produce codocytes or "target cells" which have a central collection of hemoglobin surrounded by a pallor (a thin area) then followed by a thicker collection of hemoglobin at the rim of the cell. (wikipedia.org)
  • Reticulocytosis (eg, in a hemolytic anemia) can cause macrocytosis. (msdmanuals.com)
  • Nonmegaloblastic macrocytic anemias are those in which no impairment of DNA synthesis occurs. (medscape.com)
  • Nonmegaloblastic macrocytosis is suspected in patients with macrocytic anemias when testing excludes vitamin B12 deficiency or folate deficiency. (msdmanuals.com)
  • Excessive alcohol consumption is one of the most common causes of macrocytosis and non-megaloblastic macrocytic anemia. (wikipedia.org)
  • [ 3 ] Macrocytosis may occur at any age, but it is more prevalent in older age groups because the causes of macrocytosis are more prevalent in older persons. (medscape.com)
  • Sternfeld et al, in a study using the 13 C-methionine breath test to analyze hepatic mitochondrial function in vivo in antiretroviral-treated HIV-infected patients with macrocytosis, found a significantly negative correlation between mean corpuscular erythrocyte volume and the breath test results. (medscape.com)
  • Anemia can occur in patients with macrocytosis due to mechanisms independent of the macrocytosis. (msdmanuals.com)
  • citation needed] Round macrocytes which are not codocytes are produced in chronic alcoholism (which produces a mild macrocytosis even in the absence of vitamin deficiency), apparently as a direct toxic effect of alcohol specifically on the bone marrow. (wikipedia.org)
  • Also, rapid blood replacement from the marrow after a traumatic blood loss, or rapid red blood cell turnover from rapid hemolysis (G6PD deficiency), also often produces mild macrocytosis in the associated anemia. (wikipedia.org)
  • [ 9 , 10 ] Although the macrocytosis of alcoholism may be secondary to poor nutrition with a resulting folate or vitamin B12 deficiency, it is more often due to direct toxicity of the alcohol on the marrow. (medscape.com)
  • In nonmegaloblastic macrocytosis, the marrow is not megaloblastic, but in myelodysplasia and advanced liver disease there are megaloblastoid RBC precursors with dense nuclear chromatin that differ from the usual fine fibrillar pattern in megaloblastic anemias. (msdmanuals.com)
  • Thus, chronic obstructive pulmonary disease (COPD), in which red cells are rapidly produced in response to low oxygen levels in the blood, often produces mild macrocytosis. (wikipedia.org)
  • The macrocytosis associated with COPD is also attributed to excess cell water secondary to carbon dioxide retention. (wikipedia.org)
  • Mild macrocytosis is a common finding associated with rapid blood restoration or production, since in general, "fresh" or newly produced red cells (reticulocytes) are larger than the mean (average) size, due to slow shrinkage of normal cells over a normal red cell circulating lifetime. (wikipedia.org)
  • Macrocytosis due to excess RBC membrane occurs in patients with chronic liver disease when cholesterol esterification is defective. (msdmanuals.com)
  • Macrocytosis with mean corpuscular volume of about 100 to 105 fL can occur with chronic alcohol use in the absence of folate deficiency. (msdmanuals.com)
  • Macrocytosis, sometimes without associated anemia, is often evident in persons with chronic alcoholism. (medscape.com)
  • Patients with hepatic disease and obstructive jaundice have macrocytosis that is secondary to increased deposition of cholesterol or phospholipids on the membranes of circulating red blood cells (RBCs). (medscape.com)
  • The condition of having erythrocytes which (on average) are too large, is called macrocytosis. (wikipedia.org)
  • Macrocytosis is a term used to describe erythrocytes that are larger than normal, typically reported as mean cell volume (MCV) greater than 100 fL. (medscape.com)
  • Hydroxyurea, an agent now commonly used to decrease the number of vaso-occlusive pain crises in patients with sickle cell disease, interferes with DNA synthesis, causing macrocytosis by which compliance with therapy may be monitored. (medscape.com)
  • Mild macrocytosis is a common finding associated with rapid blood restoration or production, since in general, "fresh" or newly produced red cells (reticulocytes) are larger than the mean (average) size, due to slow shrinkage of normal cells over a normal red cell circulating lifetime. (wikipedia.org)