| Study | No. of patients | Mean or median age, yr | Mean cobalamin level, pg/mL* | Other laboratory values | Peripheral smear | Clinical presentation |
|---|---|---|---|---|---|---|
| Acharya et al.4 | 3 | Patient 1: 55 Patient 2: 58 Patient 3: 91 | Patient 1: 167 Patient 2: 100 Patient 3: 162 | Patient 1: Hg 5.0 g/dL; WBC 3100 mm3; platelets 123 000/mm3; reticulocytes 6.3%; MCV 134 fL; homocysteine 62.4 μmol/L; haptoglobin < 6 mg/dL; LDH 3152 U/L Patient 2: Hg 7.7 g/dL; WBC 3400/mm3; platelets 99 000/mm3; reticulocytes 6%; MCV 115 fL; homocysteine 88.8 μmol/L; LDH 788 U/L; serum haptoglobin < 7 mg/dL Patient 3: Hg 6.6 g/dL, MCV 146 fL; platelets 97 000/mm3; homocysteine 129.7 μmol/L; haptoglobin < 7 mg/dL | Patient 1: Schistocytes and hypersegmented neutrophils Patient 2: Macrocytosis with anisopoikilocytosis, single hyperpigmented neutrophil/ granulocyte with schistocyte Patient 3: NR | Patient 1: Lethargy, confusion, exertional dyspnea, difficulty walking, moderate lower extremity edema Patient 2: Progressively increasing fatigue, bilateral paresthesias, scleral icterus Patient 3: Increasing fatigue, exertional dyspnea, right upper quadrant pain |
| Andrès et al.5 | 201 | 67 (SD ± 6) | Pseudothrombotic microangiopathy: 50 | Mean hemoglobin 10.3 g/dL; no hematological abnormalities (56 [28%]); pancytopenia 12 (5%); pseudothrombotic microangiopathy 5 (3%); hemolytic anemia 3 (2.5%); positive anti-intrinsic factor antibodies 3 (2.5%) | Hypersegmented neutrophils and macrocytosis in two-thirds of patients | Asymptomatic: one-third of patients; mild sensory polyneuropathy or confusion: 92 patients(46%); physical weakness: 40 patients (20%); bilateral edema of the legs: 24 patients (12%); jaundice: 4 patients (2%) |
| Andrès et al.7 | 6 | 77 (range 47–89) | 52 (normal 12–74) | Hemoglobin 68 g/L; platelets 70 × 109/L; homocysteine 16.2 μmol/L; positive anti-intrinsic factor antibodies 4 patients (67%) | Megaloblastic anemia and schistocytes | Asthenia and dyspnea: 6 patients (100%); jaundice: 5 patients (83%); mild peripheral sensitive neuropathy: 3 patients (50%); impaired mental status: 1 patient (17%); peripheral infiltrated cutaneous purpura: 1 patient (17%) |
| Chhabra et al.6 | 1 | 52 | 116 | Hemoglobin 4.2 g/dL; platelets 76 × 109/L; MCV 136.8.8 fL; reticulocytes 2.48%; homocysteine > 50 μmol/L; LDH 4050 U/L; haptoglobin < 10 mg/dL; positive anti-intrinsic factor antibodies | Macrocytic dysmorphic red blood cells with slight basophilic stippling, occasional schistocytes with hypersegmented neutrophils | Fatigue and chest pain |
| Garderet et al.8 | 1 | 38 | Undetectable | Hemoglobin 4.5 g/dL; WBC 2.2 × 103/L; MCV 90 fL; platelets 5 × 103/L; haptoglobin 7 mg/dL; total bilirubin 12 mg/dL; positive anti-intrinsic factor antibodies | Hypersegmented neutrophils, anisocytosis, schizocytes, and poikilocytosis | Asthenia |
| Noël et al.9 | 7 | 72 (range 43–78) | 45 μmol/L | Hemoglobin 42 g/L; platelets 73 × 109/L; reticulocytes 13.1 × 109/L; MCV 110.6 fL; LDH 7310 IU/L; haptoglobin 0.1 g/L; reticulocytes 13.1 × 109/L | Schistocytes | Mild confusion: 2 patients (28.6%) |
| Kollipara et al.10 | 1 | 42 | 59 | Hemoglobin 6.8 g/dL; WBC 1.3 × 109/L; platelets 112 × 109/L; LDH 1155 U/L; haptoglobin < 10 mg/dL; positive antiparietal cell and anti-intrinsic factor antibodies | Normocytic, normochromic anemia with ovalocytes; tear-shaped red blood cells | Asymptomatic |
| Prueksaritanond et al.11 | 1 | 52 | < 30 | Hemoglobin 5.9 g/dL; MCV 87.1 fL; LDH 701 IU/L; platelets 161 × 109/L; WBC 4.7 × 109/L; serum haptoglobin undetectable; homocysteine 100 μmol/L; reticulocyte index 0.4% | Marked anisocytosis and poikilocytoisis; tear drop cells, elliptocytes and multiple schistocytes | Increasing generalized fatigue and weakness; jaundice |
| Yeruva et al.12 | 1 | 22 | 60 | Hemoglobin 4.8 g/dL; platelets 91 000; haptoglobin 2 mg/dL; LDH 1868 IU/L; homocysteine 22.4 μmol/L; positive anti-intrinsic factor; positive antiparietal cell antibodies | Marked anisocytosis, hypochromasia with poikilocytosis, few schistocytes | Generalized fatigue and new onset dyspnea on exertion; pale conjunctiva with icteric sclera |
Note: LDH = lactate dehydrogenase, MCV = mean corpuscular volume, NR = not recorded, SD = standard deviation, WBC = white blood cells.
↵* Unless otherwise specified.