Haem practical rev 2

What is the appearance of eosinophils on a peripheral blood film?

Bilobed ("spectacle") nucleus with bright orange-pink cytoplasmic granules.

Why are eosinophil granules orange-pink?

Because they stain intensely with eosin dye.

In which infections are eosinophils typically increased?

Parasitic (especially helminthic) infections.

Which allergic conditions commonly cause eosinophilia?

Asthma and allergic disorders.

Which type of drug reaction commonly causes eosinophilia?

Hypersensitivity (allergic) drug reactions.

Which haematological malignancy is characterized by eosinophilia?

Chronic eosinophilic leukaemia.

Which lymphoma commonly presents with eosinophilia?

Hodgkin lymphoma.

What are elliptocytes?

Oval or elliptical red blood cells instead of the normal round biconcave cells.

Which inherited disorder classically produces elliptocytes?

Hereditary elliptocytosis.

Besides hereditary elliptocytosis, in which conditions are elliptocytes seen?

Iron deficiency anaemia, thalassaemia, and myelofibrosis.

What is the appearance of sickle cells on a peripheral blood film?

Elongated, crescent- or spindle-shaped red blood cells.

Why do sickle cells form?

Polymerization of HbS under low oxygen tension.

What are target cells?

Red cells with a central "bull's-eye" appearance due to an altered surface-area-to-volume ratio.

Which confirmatory tests diagnose sickle cell disease?

High-performance liquid chromatography (HPLC) and haemoglobin electrophoresis.

Which haemoglobins are quantified by HPLC/electrophoresis?

HbS, HbF, and HbA₂.

Which rapid screening tests are available for sickle cell disease?

Sickling test and solubility test.

Which tests provide the definitive diagnosis of sickle cell disease?

HPLC and haemoglobin electrophoresis.

What is the commonest acute complication of sickle cell disease?

Vaso-occlusive crisis (pain crisis).

What is dactylitis?

Painful swelling of the hands and feet due to vaso-occlusion.

What is acute chest syndrome?

A severe vaso-occlusive complication involving the lungs causing chest pain, fever, and respiratory symptoms.

What is sequestration crisis?

Sudden pooling of blood in the spleen causing hypovolaemia and severe anaemia.

Which virus commonly causes aplastic crisis in sickle cell disease?

Parvovirus B19.

What is a haemolytic crisis?

Sudden acceleration of haemolysis causing worsening anaemia.

Name the acute complications of sickle cell disease.

Vaso-occlusive crisis, dactylitis, acute chest syndrome, sequestration crisis, aplastic crisis, haemolytic crisis, priapism, and stroke.

What renal complication occurs in sickle cell disease?

Chronic renal impairment with papillary necrosis.

Which bone complication commonly affects sickle cell patients?

Avascular necrosis of the femoral head.

Which eye complication occurs in sickle cell disease?

Proliferative retinopathy.

Which pulmonary complication occurs in chronic sickle cell disease?

Pulmonary hypertension.

Which skin complication is common in sickle cell disease?

Leg ulcers.

Which biliary complication develops due to chronic haemolysis?

Gallstones (pigment stones).

Why are sickle cell patients prone to severe infections?

Autosplenectomy causes functional asplenia.

Which developmental complication occurs in children with sickle cell disease?

Growth and pubertal delay.

Name the chronic complications of sickle cell disease.

Chronic renal impairment, papillary necrosis, avascular necrosis, proliferative retinopathy, pulmonary hypertension, leg ulcers, gallstones, autosplenectomy, infection risk, and growth/pubertal delay.

What is the first-line disease-modifying drug for sickle cell disease?

Hydroxyurea.

Why is folic acid routinely prescribed in sickle cell disease?

To support increased red cell production.

Why is prophylactic penicillin given in sickle cell disease?

To reduce the risk of overwhelming bacterial infection.

Which organisms should sickle cell patients be vaccinated against?

Encapsulated organisms.

What supportive measures are used during sickle cell crises?

Analgesia and hydration.

When are blood transfusions indicated in sickle cell disease?

Severe anaemia or stroke prevention.

How should infections be managed in sickle cell disease?

Prompt diagnosis and treatment.

Which amino acid supplement is approved for sickle cell disease?

L-glutamine.

Which monoclonal antibody inhibits P-selectin in sickle cell disease?

Crizanlizumab.

Which drug increases haemoglobin oxygen affinity in sickle cell disease?

Voxelotor.

What is the only established curative treatment for sickle cell disease?

Allogeneic stem cell transplantation.

What emerging therapy offers potential cure for sickle cell disease?

Gene therapy.

How does aplastic anaemia appear on trephine bone marrow biopsy?

Hypocellular marrow with replacement by fat cells.

What is the diagnosis in a patient with a hypocellular fatty marrow?

Aplastic anaemia.

Why does aplastic anaemia produce pancytopenia?

Bone marrow hypocellularity results in failure of blood cell production.

Name an inherited cause of aplastic anaemia.

Fanconi anaemia.

What is the commonest acquired cause of aplastic anaemia?

Idiopathic aplastic anaemia.

Which antibiotic is classically associated with aplastic anaemia?

Chloramphenicol.

Which anticancer drugs may cause aplastic anaemia?

Cytotoxic chemotherapy agents.

Which environmental toxin causes aplastic anaemia?

Benzene.

Why is trephine biopsy preferred over aspiration in aplastic anaemia?

Aspiration may produce a dry tap or unrepresentative sample.

What is the curative treatment for aplastic anaemia?

Allogeneic haematopoietic stem cell transplantation.

Which patients are most suitable for stem cell transplantation?

Younger patients with a matched sibling donor.

What immunosuppressive drugs are used for aplastic anaemia?

Antithymocyte globulin (ATG) and ciclosporin.

What supportive treatments are given in aplastic anaemia?

Blood transfusion, platelet transfusion, G-CSF, and prompt infection treatment.

Which thrombopoietin receptor agonist is used in aplastic anaemia?

Eltrombopag.

What sign is seen in polycythaemia vera facies?

Facial plethora with conjunctival suffusion.

Why does facial plethora occur in polycythaemia vera?

Increased red cell mass and blood viscosity.

Which mutation is present in about 95% of polycythaemia vera cases?

JAK2 V617F mutation.

What symptom is classically triggered by a hot bath in polycythaemia vera?

Pruritus.

Which neurological symptom commonly occurs in polycythaemia vera?

Headache.

Which hepatic vein thrombosis is classically associated with polycythaemia vera?

Budd-Chiari syndrome.

What happens to erythropoietin levels in polycythaemia vera?

They are low or normal.

How do erythropoietin levels differ in secondary polycythaemia?

They are elevated.

Which molecular test confirms polycythaemia vera?

JAK2 mutation testing.

What is the target haematocrit during treatment of polycythaemia vera?

Less than 45%.

What is the main method of reducing haematocrit in polycythaemia vera?

Venesection (phlebotomy).

Why is low-dose aspirin prescribed in polycythaemia vera?

To reduce thrombotic risk.

Which cytoreductive drug is first-line for high-risk polycythaemia vera?

Hydroxyurea.

Who is considered high-risk in polycythaemia vera?

Patients older than 60 years or those with previous thrombosis.

Which JAK inhibitor is used when hydroxyurea fails?

Ruxolitinib.

What is the characteristic splenic finding in myelofibrosis?

Massive splenomegaly.

Why does bone marrow aspiration often fail in myelofibrosis?

Bone marrow fibrosis causes a dry tap.

What is the characteristic peripheral blood picture in myelofibrosis?

Leucoerythroblastic blood film with teardrop poikilocytes.

Which biopsy confirms myelofibrosis?

Trephine bone marrow biopsy showing fibrosis.

Which mutations are commonly found in myelofibrosis?

JAK2, CALR, and MPL mutations.

Which drug reduces splenomegaly in myelofibrosis?

Ruxolitinib.

Which cytoreductive drug is used in myelofibrosis?

Hydroxyurea.

Which supportive treatments are commonly used in myelofibrosis?

Blood transfusion, folic acid, and allopurinol for hyperuricaemia.

What is the only potentially curative treatment for myelofibrosis?

Allogeneic stem cell transplantation.