Analysis of case study

History 8 34 year old male. Seen for treatment of superficial skin wounds resulting from a shotgun accident while grouse hunting. Family physician noted slight pallor, jaundice, and scleral icterus. History of cholecystectomy five years prior to admission. At that time the patient was told he had Gilbert's syndrome. He stated he had always had "low blood," and that his father and paternal grandfather both had "liver ailments." Physical Exam: Somewhat pale yellowish skin with scattered small surface wounds-mostly over the face, scalp and upper extremities. Moderate scleral icterus. Spleen palpable 3 cm below the left costal margin. CBC (with microscopic differential) RBC 3.93 x 10[12]/L HGB 11.3 g/dL HCT 33.1 % MCV 84.1 fL MCH 28.8 pg MCHC 34.4 g/dL RDW 18.7 WBC 5.0 x 10[9]/L N 53 % , L 31%, M 8%, E 6%, B 2% PLT 362 x 10[9]/L

Analyze this case with answering in these questions, Question 1 What morphologic alterations are seen in this blood smear field? Question 2 What further laboratory studies, if any, are indicated? Question 3 What is the most likely diagnosis?

Answer 1 Morphologic Alterations Results of the blood smear exam were: RBC morphology: normochromic 2+ polychromasia 2+ anisocytosis 2+ spherocytes 1+ echinocytes WBC morphology: Within normal limits (one lymphocyte shown here) PLT morphology: Within normal limit

Polychromasia (also known as Polychromatophilia) is a disorder where there is an abnormally high number of red blood cells found in the bloodstream as a result of being prematurely released from the bone marrow during blood formation. These cells are often shades of grayish blue. Polychromasia is usually a sign of bone marrow stress as well as immature red blood cells.

Anisocytosis is a medical term meaning that a patient's red blood cells with unequal size.

Spherocytosis is a hereditary disorder of the red blood cells (RBCs), which may be associated with a mild anemia. Typically, the affected RBCs are small, spherically shaped, and lack the light centers seen in normal, round RBCs.

Echinocyte refers to a form of RBC that has an abnormal cell membrane characterized by many small, evenly spaced thorny projections. A more common term for these cells is burr cells.

Answer 2 Further Laboratory Studies Hematology: Reticulocytes 14.3 % Absolute 562 x 10[6]/L Osmotic fragility (unincubated) Initial hemolysis 0.65% NaCL Complete hemolysis 0.40% NaCL Control: Initial 0.50%; Complete 0.20% Osmotic fragility (incubated) Initial hemolysis 0.85% NaCL Complete hemolysis 0.60% NaCL Control: Initial 0.60%; Complete 0.20% Chemistry: Bilirubin. 0.5 mg/dL (RI 0.0-0.3) Total 5.8 mg/dL (RI 0.0-1.3)

The osmotic fragility test Non specific test. The osmotic fragility test is a measure of the resistance of erythrocytes to hemolysis by osmotic stress. The test consists of exposing red cells to decreasing strengths of hypotonic saline solutions (increasingly dilute saline solutions) and measuring the degree of hemolysis colorimetrically at room temperature. (15 ° - 20 ° C).

Normal results in osmotic fragility test The osmotic fragility of freshly taken red cells reflects their ability to take up a certain amount of water before lysing. This is determined by their volume-to-surface area ratio. The ability of the normal red cell to with stand hypotonicity results from its biconcave shape, which allows the cell to increase its volume by about 70% before the surface membrane is stretched; once this limit is reached lysis occurs. Spherocytes have an increased volume-to-surface area ratio (increased fragility); their ability to take in water before stretching the surface membrane is thus more limited than normal and they are therefore particularly susceptible to osmotic lysis. Hypotonic solutions: Cells will swell Hpertonic solutions: Cells will shrink Isotonic solutions: Cells will remain Normal results in osmotic fragility test

Blood incubated 24 hours, 37°C (g/l NaCl)   Fresh blood (g/l NaCl) Blood incubated 24 hours, 37°C (g/l NaCl) Initial lysis 5.0 7.0 Complete lysis 3.0 2.0 MCF* (50% lysis) 4.0 – 4.45 4.65 – 5.9 * MCF : Mean Cell Fragility

Diagnosis Hereditary spherocytosis Answer 3 Diagnosis Hereditary spherocytosis Clinical Course The patient was referred to a hematologist to evaluate the advisibility of a splenectomy