LABORATORIES de Guzman Raquel Isabelle & de Leon Gemma Rosa

Laboratory Findings PATIENTNORMAL VALUES Hemoglobin75 g/L120 – 160 g/L Hematocrit – 0.48 MCV78.3 fL80 – 95 fL MCH16.2 pg pg MCHC21.5 g/L30 – 35 g/dL Total WBC12.2 x 10 9 /L4.0 – 11.0 x 10 9 /L Neutrophils8.8 x 10 9 /L2.5 – 7.5 x 10 9 /L Lymphocytes3.4 x 10 9 /L1.5 – 3.5 x 10 9 /L Platelets500 x 10 9 /L150 – 400 x 10 9 /L Patient’s peripheral smear: severe hypochromic RBCs with remarkable anisocytosis, no abnormal WBCs but there are some hypersegmented neutrophils; the platelet count is increased

Laboratories Amount of circulating iron bound to transferrin Normal values: μg/dL ↓ serum iron Indirect measure of circulating transferrin Normal values: μg/dL ↑ total iron binding capacity (serum Fe x 100) / TIBC Normal values: 25% - 50% ↓ transferrin saturation Correlates with total body iron stores Normal values: adult males- average of 100 ug/L, adult females- average of 30 ug/L ↓ serum ferritin

Laboratories Information about effective delivery of iron to developing erythroblasts (sideroblasts) Normally, 20%-40% of sideroblasts have visible ferritin granules in their cytoplasm Marrow iron stain signifies inadequate Fe supply to erythroid precursors to support Hgb synthesis Normal values: <30 μg/dL > 100 μg/dL in IDA ↑ red cell protoporphyrin levels Reflect total erythroid marrow mass Normal values: 4-9 μg/L Elevated in absolute Fe deficiency Serum transferrin receptor protein

What Happens When There is Gradual Depletion of Iron Stores?

Other Laboratory tests to establish IDA etiology Testing stool for the presence of hemoglobin – to establish GI bleed as etiology of IDA – chemical testing that detects more than 20 mL of blood loss daily from the upper gastrointestinal tract is employed – benzidine method, or red blood cells can be radiolabeled with radiochromium and retransfused

Test for Hemoglobinuria – Is suspected if a freshly obtained urine specimen appears bloody but contains no red blood cells – Confirmed by precipitation of hemoglobin but not myoglobin using 60% ammonium sulfate

With less severe hemolytic disorders, there may be no significant hemoglobinuria. – Investigate renal loss of iron by staining the urine sediment for iron. Hemosiderin is detected intracellularly.

“When the diagnosis remains ambiguous after laboratory results are analyzed, a bone marrow biopsy should be considered in order to make a definitive diagnosis. The absence of stainable iron is the ‘gold standard’ for diagnosis of IDA.” Zhu, A. et al. Evaluation and Treatment of Iron Deficiency Anemia: A Gastroenterological Perspective Dig Dis Sci January; 55(3): 548–559.

Bone Marrow Aspirate Largely replaced by measurement of serum iron, TIBC, and serum ferritin in diagnosing iron deficiency anemia The absence of stainable iron in a bone marrow aspirate that contains spicules and a simultaneous control specimen containing stainable iron permit establishment of a diagnosis of iron deficiency without other laboratory tests. Also diagnostic in identifying the sideroblastic anemias by showing ringed sideroblasts in the aspirate stained with Perls stain.