A case of pernicious anaemia due to vitamin B12 deficiency

A. Mahalakshmi

Physician Assistant, Kauvery Hospital, Cantonment, Trichy

Abstract

Pernicious anaemia is megaloblastic anaemia resulting from impaired vitamin B12 absorption. It is primarily caused by autoimmune destruction of the gastric parietal cells, leading to a deficiency in Intrinsic Factor and, consequently, a failure to absorb vitamin B12. I report the case of a 47 years aged male patient who presented with generalized weakness, tiredness, loss of appetite, loss of weight and anasarca, with swelling of both legs. He was found to have severe anaemia (haemoglobin – 3.3g/dl), associated with pancytopenia. Extensive workup revealed vitamin B12 deficiency secondary to pernicious anaemia.

Background

Inadequate consumption of animal food and pernicious anaemia (loss of intrinsic factor due to autoimmune atrophic gastritis) are the most common causes of severe vitamin B12 deficiency worldwide in children and adults. Most of the vitamin B12 deficient patients have only mild haematological findings. In approximately 10% of patients, life-threatening conditions such as symptomatic pancytopenia and severe anaemia can occur (haemoglobin level< 6g/dl).

Case presentation

A 47 years old vegetarian male patient presented with generalised weakness, tiredness, loss of appetite, loss of weight and swelling both legs, noted during the past few weeks.

No history of fever

Non – smoker/Non alcoholic

On examination

Patient was conscious, oriented, afebrile

The patient looked pale and weak +

Bilateral pitting pedal edema +

Anasarca +

Bp – 110/70mmhg

Pulse rate- 86/min, SpO2 – 100%

CVS- S1 S2 +, RS- b/l NVBS +, P/A – Soft

Lab investigations

  • Severe anaemia, (Haemoglobin – 3.3g/dl)
  • Leukopenia (WBC- 1700 )
  • Thrombocytopenia (platelet – 32000/mm3)
  • Reticulocyte percentage – 0.3%
  • Erythrocyte sedimentation rate – 120mm/1hr

Liver function tests

  • T-Bilirubin – 2.89
  • Bilirubin – 2.44
  • Serum LDH was high – 2263u/l

Vitamin D – 4.8 nh/ml

Total vitamin B12 – < 147 pg/ ml

Peripheral smear study showed – pancytopenia.

Iron studies

  • Iron- 205
  • TIBC- 230
  • Transferrin saturation – 89.1
  • Ferritin – 44.20

Viral markers / Stool occult blood/ Blood /Urine culture & sensitivity were all negative.

OGD scopy done showed-? Atrophic gastritis.

Echo was normal.

USG abdomen showed – bilateral mild pleural effusion.

Chest X-ray was un remarkable

Diagnosis and treatment

Based on the clinical presentation and laboratory findings a diagnosis of pernicious anaemia due to vitamin B12 deficiency was made.

Blood transfusion given in view of anaemia

The patient was then treated with a series of vitamin B12 intramuscular injections and oral vitamin supplements were given which resulted in gradual improvement of his symptoms.

Conclusion

The diagnosis of pernicious anaemia due to vitamin deficiency was based on clinical, and cytological elements and the assay of associated biomarkers. Due to the nonspecificity of clinical signs, the serum level of vitamins B12 can be included in the initial assessment of pancytopenia.

The manifestations of cobalamin and folate deficiency are relatively similar, reflecting their intricate co-enzymatic functions. In industrialized countries, provided the diet is balanced and in the absence of underlying disease, vitamin requirements are covered and deficiencies of nutritional origin are rare. Vitamin B12 substitution, traditionally administered intramuscularly, is effective orally in children for nutritional deficiencies. Folic acid supplementation is administered orally. The importance of early diagnosis and prompt vitamin supplementation, due to potential complications, must be emphasized.

The clinical manifestations of vitamin B12 deficiency can be nonspecific, resulting in delayed diagnosis. The diagnosis should be considered in patients with neuropsychiatric, gastrointestinal, hematologic, or cutaneous abnormalities. Vitamin B12 deficiency can manifest without the typical hematologic changes. Hyperpigmentation may be the first sign of vitamin B12 deficiency. It should be considered by clinicians in the differential diagnosis of palmoplantar hyperpigmentation, as early treatment can avert permanent disability in this patient.

A. Mahalakshmi
Physician Assistant

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