Haematological features of HIV infection
Altered Haemopoiesis § Viral § Direct infection of precursor cells § Altered production of regulatory cytokines (eg. Overproduction of TNF has an inhibitory effect on marrow progenitor cells) § Dysplasia § Dyserythropoieis is most common – 50% § Abnormal granulocytic and megakaryocytic development – 30% § Myelodysplasia in HIV is not considered to be pre-leukaemic § Drugs § Antiretrovirals § Cotrimoxazole / pentamidine § Dapsone – AIHA § Ganciclovir
Thrombocytopenia § Common at all stages of disease § Often due to immune destruction § Increased megakaryocytes / platelet IgG § Reduced production § Treatment similar to ITP but avoid steroids if possible § Hypersplenism § Drug toxicity § TTP
Neutropenia § Incidence increases as HIV disease progresses § Impaired haemopoiesis main mechanism § Anti-neutrophil antibodies found in some patients § Poor correlation with counts § Generally well tolerated unless <0.5 x 109 § Treated with GCSF
Anaemia § Multiple causes § Impaired erythropoiesis § Drug therapy (zidovudine) § Reticuloendothelial iron block due to chronic infections § Marrow infiltration § Haemolysis unusual (but DAT +ve in 6-43%) § B12 deficiency (10-35%) § Probably due to malabsorption of B12 § Partial villous atrophy common § Infection (chronic parvovirus) § Treatment § EPO if level <500 IU/L § Transfusion § Immunoglobulin can be helpful in parvovirus infection
Bone marrow changes § Cellularity § 50% hypercellular § 15% hypocellular Dysplasia § 70% show some dysplastic features § Erythroid dysplasia 60% § Granulocytic dysplasia 30% § Megakaryocytes 30%
§ Not generally a preleukaemic state § No chromosomal abnormalities
§ Histiocytes increased § Haemophagocytosis
§ Plasma cells increased § May be atypical § Paraproteiniaemia in 9% of HIV positive (excluding AIDS) § Some paraproteins directed against gag and pol
§ Fibrosis § 20-50% of trephines
Lupus anticoagulant § Prolonged APTT § Thrombotic events rare in patients with HIV when compared to other patients with APL antibodies § Mechanism unknown § Association with opportunistic infection § P. carinii
AIDS-Related lymphoma § Non-Hodgkin’s lymphoma § Diffuse large cell (65%) § 12% Primary intracerebral § Burkitt’s (33%) § Primary effusion (2%) § Castleman’s disease Hodgkin’s lymphoma § Increased up to 8-fold § Largely EBV related
Castleman’s disease Kaposi’s sarcoma herpes virus (also causes primary effusion lymphoma) Lymphadenopathy with angiofollicular hyperplasia and plasma cell infiltration |
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