1st order laboratory parameters – obligatory laboratory tests.
- Small blood count:
- Hypochromic anemia (microcytic anemia; MCH ↓ → hypochromic; MCV↓ → microcytic).
- Normochromic anemia (normocytic anemia; MCH normal → normochromic; MCV normal → normocytic).
- Hyperchromic anemia (macrocytic anemia; MCH ↑ → hyperchromic; MCV ↑ → macrocytic) / megaloblastic anemia.
- Hemolytic anemia (MCH normal → normochromic; MCV ↑ → macrocytic; elevated are: Urinary urobilin (dark urine), indirect bilirubin, LDH, HBDH, iron, free hemoglobin, reticulocytes and ESR; decreased is: haptoglobin).
- Differential blood count
- Red cell morphology (blood smear; abnormal shape and stainability, inclusion body).
- Ferritin
- Folic acid
- Vitamin B12
- Iron
- Reticulocytes
- Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
- Urine status (rapid test for: pH, leukocytes, nitrite, protein, glucose, ketone, urobilinogen, bilirubin, blood), sediment, if necessary urine culture (pathogen detection and resistogram).
- Test for occult (not visible) blood in the stool.
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.
- Transferrin
- Transferrin saturation
- Iron absorption test – for suspected iron reabsorption disorderProcedure: If serum iron increases by at least 9 μmol/l within 2 hours after oral administration of 200 mg divalent iron in a fasting, supine patient, intact iron absorption is present. In the absence of an increase after 4 hours, iron reabsorption disorder is present.
- Soluble transferrin receptor
- Direct Cooms Test (DCT) – suspected transfusion incident, autoimmune hemolytic anemia (AIHA), haemolyticus neonatorum disease.
- Haptoglobin [iron deficiency anemia: normal] – due todiagnostics [hemolytic anemias: ↓] and Verlaufsbur of the terribly division of hemolytic diseases.
- Osmotic fragility of erythrocytes (“acidified glycerol lysis test”, AGLT), band 3 protein expression (“eosin-‘-maleimide test”, EMA), enzyme activities (G6PD and pyruvate kinase), and Hb analysis – for unclear DCT-negative hemolytic anemias.
- Zinc protoporphyrin – is present at elevated levels in iron deficiency.
- Lactate dehydrogenase (LDH)
- Renal parameters – urea, creatinine, cystatin C or creatinine clearance, as appropriate.
- Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), glutamate dehydrogenase (GLDH), gamma-glutamyl transferase (γ-GT, gamma-GT; GGT), alkaline phosphatase, indirect bilirubin.
- TSH (thyroid-stimulating hormone).
- Bone marrow biopsy by Jamshidi puncture (bone punch) – in cases of prolonged hypoplastic anemia (e.g., due to malignant bone marrow involvement, suspected myelodysplastic syndrome with bi- or tricytopenia or dyserythropoietic anemia).
- Hemoglobin electrophoresis / hemoglobin chromatography.
- Serum protein electrophoresis – exclusion of plasmocytoma (multiple myeloma).
- Serology in suspected immunological causes
- Cytogenetic studies when a congenital form of aplastic anemia is suspected.
Further notes
- Often to be differentiated from iron deficiency anemia is differential diagnosis of bleeding anemia. For this, a decreased number of erythrocytes and a decreased hemoglobin concentration in the blood is characteristic. Furthermore, peripheral reticulocytosis occurs in bleeding anomaly.Bleeding anemia is caused by acute blood loss. The source of bleeding is mainly genital or gastrointestinal.
