Tuesday, August 10, 2010

Mean Corpuscular Hemoglobin Concentration (MCHC)

Mean Corpuscular Hemoglobin Concentration (MCHC)

Introduction
      MCHC is calculated as Hb divided by Hct.
      
      Normal Range
      32-38 %

      Indications
For laboratory quality control, chiefly because changes occur very late in the course of iron deficiency when anemia is severe and for instrument calibration.

Increased in
Hereditary spherocytosis (MCHC is > 36 gm/dL), infants and newborns, other causes due to automated cell counters are hemolysis, cold agglutinins, lipemia, rouleaux or RBC agglutinates.

Decreased in
Hypochromic anemia (Low MCHC may not occur in iron deficiency anemia when measured with automated instruments), marked leukocytosis (automated cell counter).

Wednesday, August 4, 2010

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.