Q1. Which pattern of iron studies indicates IRON DEFICIENCY rather than anaemia of chronic disease? A. Low ferritin, high TIBC B. High ferritin, low TIBC C. Normal ferritin, normal TIBC D. High ferritin, high TIBC ANSWER: A — low ferritin with high TIBC. Why: empty stores lower ferritin, and the body upregulates transferrin to capture what iron there is, raising TIBC. B: describes anaemia of chronic disease, where iron is sequestered rather than absent. LEARNING POINT: ferritin reflects stores; TIBC reflects the attempt to acquire more.

Q2. Which deficiency causes subacute combined degeneration of the spinal cord? A. Iron B. Folate C. Vitamin B12 D. Vitamin C ANSWER: C — vitamin B12. Why: B12 is required for myelin maintenance, and deficiency damages the dorsal columns and corticospinal tracts. Folate deficiency causes an identical anaemia but NO neurological disease. LEARNING POINT: this asymmetry is why folate must never be given alone when B12 deficiency is possible.

Q3. A 70-year-old man has Hb 94 g/L, MCV 71 fL and ferritin 9 µg/L. Bowel habit is normal. The most important management step is: A. Oral iron and review in 3 months B. Oral iron AND investigation of the gastrointestinal tract C. Blood transfusion D. Reassure — this is age-related ANSWER: B — iron AND GI investigation. Why: iron deficiency in a man has no normal physiological cause and indicates occult blood loss until proven otherwise. A normal bowel habit does not exclude a right-sided colonic tumour, which bleeds silently. A: treats the number and misses the cause. LEARNING POINT: the anaemia is the presenting sign of something else.

Q4. A patient with rheumatoid arthritis has Hb 97 g/L, MCV 77 fL, ferritin 90 µg/L and CRP 70. The correct interpretation is: A. Iron deficiency is excluded by the ferritin B. Iron deficiency may still be present — ferritin rises with inflammation C. This is certainly thalassaemia D. Transfusion is required ANSWER: B. Why: ferritin is an acute phase protein. In active inflammation a "normal" value can coexist with depleted stores, and the microcytosis is a clue since anaemia of chronic disease is more often normocytic. LEARNING POINT: a LOW ferritin is diagnostic; a normal one proves nothing in an inflamed patient.

Q5. A 60-year-old with macrocytic anaemia has paraesthesiae and impaired proprioception. Folate is low; B12 result pending. The correct action is: A. Start folic acid now B. Wait for the B12 and treat B12 first, or give both C. Transfuse D. Start iron ANSWER: B. Why: folate alone can partly correct the anaemia while allowing subacute combined degeneration to progress. The neurological signs point to B12 deficiency. A: the specific error this question targets. LEARNING POINT: replace B12 first, or give both together.

Q6. A man develops acute haemolysis after nitrofurantoin. Film shows bite cells; Coombs is negative. A G6PD assay during the episode is normal. This means: A. G6PD deficiency is excluded B. The assay may be falsely normal because deficient cells have already been destroyed C. The haemolysis is autoimmune D. The film is misreported ANSWER: B. Why: during acute haemolysis the oldest, most deficient cells lyse first, leaving reticulocytes with higher enzyme activity — so the assay reads falsely normal. Repeat it after recovery. C: a negative Coombs argues against an immune mechanism. LEARNING POINT: timing changes the result. Retest when the episode has settled.

Q7. A 26-year-old of South Asian origin has Hb 108 g/L, MCV 63 fL, normal ferritin and a raised red cell count. The most likely diagnosis is: A. Iron deficiency anaemia B. Thalassaemia trait C. Anaemia of chronic disease D. Megaloblastic anaemia ANSWER: B — thalassaemia trait. Why: marked microcytosis with only mild anaemia, a normal or raised red cell count and normal iron studies is the classic pattern. Iron deficiency reduces the red cell count as well as the size. A: excluded by the normal ferritin. LEARNING POINT: giving iron here achieves nothing and risks overload. Confirm with electrophoresis or HPLC, and consider the genetic counselling implications.