HIV and haematology

Rewriting the textbooks

HIV has changed everything…

1. Common findings

2. Rare and life-threatening HIV-related conditions

3. Treatment-related changes

NEVER FORGET

People with HIV have other diseases as well

Anaemia

Virtually 100% of HIV positive individuals by the time AIDS develops.

Negative prognostic indicator – independent of CD4 count and viral load

Cytopenias

Decreased production

Increased destruction/ sequestration/ loss

Decreased red cell production

1. Anaemia of chronic disorders:

decreased responsiveness to erythropoietin (cytokine related)

RE iron blockade

shortened red cell survival

2. Ineffective erythropoiesis

3. Marrow infiltration

Increased red cell loss

1. Splenomegaly

2. Immune destruction

Thrombocytopenia

Early:

Increased loss >>> decreased production

Later:

Decreased production becomes increasingly important

ITP in HIV

• Frequently occurs before any other manifestation of HIV

• May be severe and life-threatening

• Responds to HAART and standard therapy – splenectomy contraindicated

Thrombocytopenia

• Increased loss:

splenomegaly

• Decreased production:

ineffective thrombopoiesis

marrow infiltration

Neutropenia

Decreased production >>> increased loss

• Ineffective – marked dysplastic changes especially in the presence of additional marrow infection.

• Suppression

• Splenomegaly

• Autoimmune destruction

Neutrophil dysplasia

Neutrophil dysplasia

Typical bone marrow findings

• Cellularity: Normal to reduced Few adipocytes Increased macrophages Tatty and disorganised Fine fibrosis Open sinusoids Serous degeneration

HIV bone marrow

Serous degeneration

Marrow appearances continued…

• Evidence of inflammation

plasma cells

lymphoid aggregates

macrophages

Macrophages

Marrow appearances continued…

• Erythropoiesis: reduced and right-shifted disordered increased iron stores• Granulopoiesis: normal to reduced dysplasia• Thrombopoiesis: ITP: normal to increased dysplasia

ITP

Rare and life-threatening conditions

Microangiopathic haemolysis

• TTP• HUS• DIC

Pure red cell aplasia

• Not on ART – Parvovirus B19

• On ART – AZT (Zidovudine)

• Consider autoimmune

Haemophagocytic syndrome

Don’t forget…

• Lymphomas

• Myeloma

• Other rarer malignancies

• Infections –TB, cryptococcus…

• Coagulation – antibodies to factors, lupus anticoagulant

• Thrombosis – inflammation, reduced Protein S, endothelium

Mycobacteria

Cryptococcus

Drug effects

• Zidovudine – AZT pure red cell aplasia reduced

erythropoiesis macrocytosis myeloid suppression• Cotrimoxazole neutropenia, thrombocytopenia• 3TC Lamivudine – pure red cell aplasia