Clinical Case: Vitamin B12 Deficiency and Pernicious Anemia
Colleagues, today we will discuss a case from practice that clearly demonstrates how complete blood count and biochemistry indicators help identify a systemic autoimmune process.
Patient: female, 65 years old. Complaints: memory loss, irritability, shortness of breath, icteric sclera, and paresthesias (“tingling sensation”) in the feet.
Examination revealed neurological disorders: absence of knee reflexes, positive Babinski sign, and ataxic gait.
Laboratory test results:
✅ Hematological parameters:
- Severe anemia (hemoglobin 70 g/L).
- Macrocytosis (mean corpuscular volume 112 fL).
- Pancytopenia (decreased leukocyte and platelet levels).
- In blood smear: anisocytosis, poikilocytosis, presence of macrocytes and hypersegmented neutrophils.
- Low reticulocyte count (25 x 10⁹/L), indicating ineffective erythropoiesis.
✅ Biochemical markers:
- Elevated total bilirubin (28 µmol/L).
- Critically elevated lactate dehydrogenase (over 5000 U/L), which is characteristic of massive destruction of erythrocyte precursors in the bone marrow.
- Hypokalemia (potassium 2.8 mmol/L) — a consequence of renal tubule dysfunction due to DNA synthesis defects.
✅ Specific tests:
- Serum vitamin B12 level significantly reduced (50 ng/L).
- Antibodies to intrinsic factor and gastric parietal cells detected.
Diagnosis: Pernicious Anemia.
Case features: Neurological symptoms (subacute combined degeneration of the spinal cord) are due to impaired myelin methylation. It is important to remember that administering folic acid without correcting B12 deficiency can improve hematological parameters but irreversibly worsen nervous system damage.
Outcome: After initiating therapy with vitamin B12 and potassium preparations (to prevent “rebound” syndrome upon activation of hematopoiesis), the patient’s condition significantly improved, cognitive functions recovered, and blood parameters normalized within 5 weeks.
Have you encountered such high LDH values in megaloblastic anemias in your practice?
