Question

67-year-old female presents with chief complaint of shortness of breath, fatigue, weakness, unintentional weight loss, and mild numbness in her feet. She states she feels unsteady when she walks. PMH includes hypothyroidism well controlled on Synthroid 100 mcg/day. No hx of HTN or CHF.

Vital signs: Temp 98.7 F, pulse 118, Respirations 22, BP 108/64, PaO₂ 95% on room air.

Physical revealed pale, anxious female appearing older than stated years.

HEENT- pale conjunctiva of eyes and pale palate. Tongue beefy red and slightly swollen with loss of normal rugae. Turbinates pale but no swelling. Thyroid palpable but no nodules felt. No lymph nodes palpated.

Cardiac-regular rate and rhythm with soft II/VI systolic murmur. Respiratory- lungs clear with no adventitious breath sounds. Abdomen-soft, non-tender with positive bowel sounds. Liver edge palpated two finger breadths below right costal margin. Lab data- hgb, hct, reticulocyte count, serum B₁₂ levels low, mean corpuscle volume, plasma iron, and ferritin levels high, folate, TIBC are normal.

Explain the following related to this case study:  Anemia and the different kinds of anemia (i.e., micro and macrocytic).

Answer 1

ANEMIA

DEFINITION - It is defined as decrease in the total amount of red blood cells (RBCs) or hemoglobin in the blood or decrease in oxygen carrying capacity.

TYPES - On the basis of morphology of RBC they are devided into 3 typrs

1) Normocytic (MCV - Mean Corpuscular Volume is normal i.e. 80 and 96 femtoliters(fL) per cell)

2) Microcytic (MCV is less than 80 fL)

3) Macrocytic (MCV is more than 96 fL)

Most common cause of Microcytic anemia are - 1) Iron deficiency anemia and 2) Beta-Thalassemia

Cause of macrocytic anemia is - Folate or Vit B-12 deficiency

Cause of Normocytic anemia - Acute blood loss (haemorrhage)

Following table will help you to differentiate different kind of anemia

MORPHOLOGY	LAB TEST	DIAGNOSIS
Microcytic , hypochromic	Low Serum Iron, High TIBC, Low Serum ferritin	IRON DEFICIENCY ANEMIA
Microcytic , hypochromic	High Hb A2	Beta-Thalassemia
Macrocytic	Low B-12 or Low Folate level in serum	Folate or Vit B-12 deficiency

Now coming to our case - case of hypothyroidism with Labs as following

LOW - hgb, hct, reticulocyte count.

HIGH - mean corpuscle volume(MCV), plasma iron, and ferritin levels.

NORMAL - folate, TIBC

So let us understand the pathophysiology of what happens in Hypothyroidism, Thyroid hormones plays very important role in erythropeisis(prcess of formation of RBC), so when there is thyroid deficiency it affects Erythropoeisis, SO IT RESULTS INTO LOW RBC SO LOW HAEMOGLOBIN and also LOW RETICULOCYTE COUNT.

As iron is not utilized in formation of RBC so plasma iron, and ferritin levels increases and as we know that deficient iron in RBC results in increase in size of RBC i.e. increase in MCV

fOLATE AND TIBC has nothing to do with it so they are normal