Mean Corpuscular Hemoglobin (MCH)

Mean Corpuscular Hemoglobin (MCH)

Introduction

MCH is calculated as Hb divided by total RBC count.

Normal range

            Adults – 27-31Pg
            New born – 33- 39Pg

Indications

Limited value in differential diagnosis of anemias; Used for instrument calibration.

Increased in

Macrocytic anemia, infants and newborns, marked leukocytosis( > 50,000/cu.mm),cold agglutinins, in vivo hemolysis, monoclonal proteins in blood, high heparin concentration, lipemia.

Decreased in

Microcytic and normocytic anemias.

Causes of lymphocytosis (> 4000/cumm in adults, > 7200/cumm adolescents, > 9000/cumm in children and infants)

Causes of lymphocytosis (> 4000/cumm in adults, > 7200/cumm adolescents, > 9000/cumm in children and infants)

Infection (Pertusis, infectious, lymphocytosis, infectious hepatitis, cytomegalovirus (CMV) infections, mumps, rubella, varicella, toxoplasmosis, chronic tuberculosis), 

Others like thyrotoxicosis, 

Addison's disease,

neutropenia with relative lymphocytosis, 

lymphatic leukemia, 

Crohn's disease, 

ulcerative colitis and 

infancy (normal count 40- 60 %) called relative lymphocytosis.

Mean Corpuscular Volume (MCV)

Mean Corpuscular Volume (MCV)

Introduction

MCV is calculated as hematocrit (Hct) divided by RBC count with manual methods measured directly by automated instruments.

 

Normal range

Adults – 78-100Fl

Neonates- 102-115Fl.

Indications

Classification and differential diagnosis of anemia; useful screening test for occult alcoholism

Increased in (MCV > 95fL, Often > 110Fl)

All macrocytic anemias (megaloblastic anemias, Vit. B12’ folate deficiency, sprue, macrocytic anemia of pregnancy, megaloblastic anemia due to alcoholism, liver disease and hypothyroidism), infants and newborns.

 

Decrease in (MCV < 80FL)

Microcytic anemias

Usually hypo chromic (e.g. iron deficiency, pyridoxine – responsive thalassemia,   lead poisoning), chronic disease, abnormal HbC and HbE.