Hematological findings in patients with food-cobalamin malabsorption

Pseudomicroangiopathic Thrombotic Syndrome: Unveiling the Vitamin B12 Deficiency Connection

Pernicious anemia, a manifestation of vitamin B12 deficiency, can present with a spectrum of hematological abnormalities, sometimes mimicking more severe conditions such as thrombotic microangiopathy (TMA). This case report details a 53-year-old female who presented with significant weight loss, watery diarrhea, and jaundice. Laboratory investigations revealed pancytopenia, hemolysis, and schistocytes, initially suggesting a diagnosis of microangiopathic hemolytic anemia (MAHA). However, significantly low vitamin B12 levels and subsequent bone marrow examination confirmed pernicious anemia with megaloblastic changes. This case underscores the importance of considering vitamin B12 deficiency in the differential diagnosis of patients presenting with TMA-like symptoms. Early recognition and treatment with vitamin B12 supplementation led to rapid clinical improvement and the resolution of symptoms. This report highlights the need for heightened clinical awareness of atypical presentations of pernicious anemia to prevent misdiagnosis and ensure timely, effective treatment.

[Cobalamin deficiencies in adults: update of etiologies, clinical manifestations and treatment]

PURPOSE

Update of the adult cobalamin deficiencies.

CURRENT KNOWLEDGE AND KEY POINTS

More precise definitions establish the true cobalamin deficiencies and determine their real epidemiology. The current clinical data suggest the concept of food-cobalamin malabsorption as the leading etiology of cobalamin deficiency. The new features of cobalamin deficiency include neurological, gynecological and vascular manifestations. Current treatment modalities include nasal, sublingual and oral cobalamin administration.

PROSPECTS AND PROJECTS

Studies are in the way to establish the relevance of the new clinical manifestations and to validate the usefulness of oral cobalamin therapy.

Food-cobalamin malabsorption in elderly patients: clinical manifestations and treatment

PURPOSE

Approximately 15% of people aged more than 60 years old have a cobalamin (vitamin B12) deficiency, mainly in relation with food-cobalamin malabsorption (FCM). To date, no study has documented this disorder in the elderly. There is also little information on clinical consequences.

SUBJECTS AND METHODS

We studied 92 elderly patients with well-established FCM who were extracted from an observational cohort study (1995-2004) of 172 consecutive elderly patients with documented cobalamin deficiency.

RESULTS

The median patient age was 76 +/- 8 years; 60 patients were women. The most common clinical manifestations were neurologic or psychologic: mild sensory polyneuropathy (44.6%), confusion or impaired mental functioning (22.8%), and physical asthenia (20.7%). Hematologic abnormalities were reported in at least one third of the patients: anemia (21%), leukopenia (10.9%), thrombopenia (8.7%), and pancytopenia (6.5%). All patients had low serum vitamin B12 levels (<200 pg/mL), with a mean value (+/- standard deviation) of 131 +/- 38 pg/mL and total serum homocysteine level of 22.1 +/- 9.3 micromol/L. The mean hemoglobin level was 10.9 +/- 2.5 g/dL and the mean erythrocyte cell volume 95.7 +/- 12.7 fL. Correction of the serum vitamin B12 levels and hematologic abnormalities was achieved equally well in patients treated with either intramuscular or oral crystalline cyanocobalamin.

CONCLUSIONS

This study suggests that in elderly patients, FCM may be associated with significant neurologic, psychologic, and hematologic abnormalities, which seem to respond equally well to either oral or parenteral vitamin B12 therapy.

Vitamin B12 (cobalamin) deficiency in elderly patients

Vitamin B12 or cobalamin deficiency occurs frequently (> 20%) among elderly people, but it is often unrecognized because the clinical manifestations are subtle; they are also potentially serious, particularly from a neuropsychiatric and hematological perspective. Causes of the deficiency include, most frequently, food-cobalamin malabsorption syndrome (> 60% of all cases), pernicious anemia (15%-20% of all cases), insufficient dietary intake and malabsorption. Food-cobalamin malabsorption, which has only recently been identified as a significant cause of cobalamin deficiency among elderly people, is characterized by the inability to release cobalamin from food or a deficiency of intestinal cobalamin transport proteins or both. We review the epidemiology and causes of cobalamin deficiency in elderly people, with an emphasis on food-cobalamin malabsorption syndrome. We also review diagnostic and management strategies for cobalamin deficiency.