The haematological features of HIV infection.13769DEFANGED-ppt 3.57.51 PM

The haematological features of HIV infection.13769DEFANGED-ppt 3.57.51 PM

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Unformatted text preview: The haematological features of HIV infection of British Journal of Haematology, British 1997, 99, 1-8 1997, Review article B. J. Bain B. Why? Why? • With the continuing rise With in the prevalence of HIV world-wide, knowledge of the haematological features of HIV infection and AIDS is becoming increasingly important. increasingly The haematological features of HIV infection of • Infection by the HIV and the consequent Infection fully developed AIDS can have profound haematological effects in haematological – the primary infection period – the phase of clinical latency, and – patients with advanced disease Causes of the haematological changes changes • The haematological abnormalities may The be attributable to the: be • Direct and indirect effect of HIV infection • opportunistic infections • Toxicity of the drugs Diagnostic confusion Diagnostic • It is important for the haematologist to be It aware of the features of HIV infection and AIDS since diagnostic confusion can diagnostic otherwise occur. otherwise • HIV infection can simulate the: – – – MDS MPD, and T-cell lymphoma T-cell Primary infection Primary • Brief febrile illness Brief febrile • Pharyngitis and cervical lymphadenopathy are cervical common, simulate infectious mononucleosis. common, • Initial lymphopenia Initial lymphopenia • Followed by lymphocytosis with atypical lymphocytes. Followed lymphocytosis • False positive Paul Bunnell test. • Neutropenia, thrombocytopenia and transient Neutropenia, pancytopenia can also occur. pancytopenia Established infection • Primary infection is followed by a period of Primary clinical latency or asymptomatic infection. clinical asymptomatic • Isolated thrombocytopenia as a result of immune destruction of platelets can occur. immune • There is increased platelet associated Ig. There Ig General haematological features of AIDS General • Peripheral blood – During the asymptomatic period, there is During asymptomatic • Gradual fall in the number of CD4 + lymphocytes CD4 • Initial increase in CD8 lymphocytes Initial increase CD8 – By the time of diagnosis there is By diagnosis • • • Lymphopenia Often pancytopenia Often pancytopenia Anaemia which is usually normochromic, normocytic but sometimes macrocytic. sometimes Peripheral blood changes Peripheral • Red cell changes – – – – – Anisocytosis, Anisocytosis, poikilocytosis, poikilocytosis, rouleaux formation increased background staining. increased Occasionally the blood film shows features of Occasionally microangiopathic haemolytic anaemia. microangiopathic Peripheral blood changes Peripheral • Neutrophils may show dysplastic features: Neutrophils dysplastic – – – – – – toxic granulation Dohle bodies Dohle cytoplasmic vacuolation cytoplasmic left shift left presence of detached nuclear fragments hypogranularity and occasional Pelger forms Neutrophil with a detached Neutrophil nuclear fragment in AIDS • a detached nuclear fragment can be seen in AIDS patients • It can also be caused by It multi-agent cytotoxic multi-agent chemotherapy chemotherapy Peripheral blood changes Peripheral • Thrombocytopenia , usually normal size platelets. platelets. • Except when there is immune Except immune destruction, large size platelets may be large seen. seen. Bone marrow aspirate Bone • It is initially hypercellular, but is hypocellular in It hypercellular but hypocellular the later stages. the • Trilineage dysplasia is common. Trilineage dysplasia Bone marrow aspirate Bone • Changes in the erythrocytes include: – – – – – – – – Nuclear lobulation and fragmentation Howell-Jolly bodies Bi- and multi-nuclearity Cytoplasmic bridging Cytoplasmic vacuolation Basophilic stippling Megaloblastosis. Occasional ring sideroblasts. Bone marrow aspirate Bone • Changes in the myeloid series include: Changes myeloid – Dysplastic changes – Giant metamyelocytes are common even in the absence of megaloblastic erythropoiesis. erythropoiesis. Giant metamyelocyte Giant A hypogranular giant metamyelocyte in the peripheral the blood of a patient with AIDS. with Bone marrow aspirate Bone • Changes in megakaryopoiesis Changes – Megakaryocytes are increased early in the increased early disease and decreased in the later stages. in stages – They show dysplastic features They dysplastic • Bizzare nuclear shapes • Hyperchromatic nuclei • Nuclear hypolobulation Bone marrow aspirate Bone • Reactive changes include: – Increased lymphocytes – Increased plasma cells – Increased macrophages – Haemophagocytic syndrome Differences between HIV and MDS in the BMA MDS • • • • In HIV In Ring sideroblasts are Ring not a prominent feature not Myeloblasts are not Myeloblasts increased increased Micromegas are not Micromegas common common Auer rods are not seen In MDS In • Giant Giant metamyelocytes (common in AIDS) are quite uncommon in MDS. in Bone marrow trephine biopsy Bone • Initially shows hypercellularity with neutrophil and Initially hypercellularity megakaryocytic hyperplasia. megakaryocytic • Megakaryocytes are clustered and dysplastic Megakaryocytes clustered dysplastic • There is increased number of bare megakaryocyte There bare nuclei. nuclei. Bone marrow trephine biopsy in Bone AIDS showing dysplastic megakaryocytes (H & E) • The megakaryocytes are hypolobulated clustered. clustered. and Bone marrow trephine biopsy Bone • Reticulin is often increased. • Late in the course of the disease the trephine biopsy Late will show hypocellular BM with gelatinous hypocellular degeneration degeneration • Patches of necrosis Patches necrosis • Patients with specific infections may show BM Patients granulomas. granulomas. • Lymphomatous infiltration A random focal lymphoid random infiltrate (H & E) • A random focal lymphoid infiltrate [arrow] in a patient with AIDS. with Specific infections in AIDS Specific • Opportunistic infections are very common in Opportunistic AIDS, among these are: AIDS, • Mycobacterial and other bacterial infections – – – Mycobacterium tuberculosis Atypical mycobacterial infection Mycobacterium avium intracellulare • The bone marrow in patients with mycobacterial The infection may show well-formed, or less formed granulomas. granulomas. • Caseation may occur in tuberculous granulomas. • Sometimes there is marked proliferation of foamy Sometimes macrophages macrophages • Culture for mycobacteria is obligatory whenever a BM examination is performed to investigate fever of unknown origin in an HIV + patient. unknown Trephine biopsy in atypical Trephine mycobacterial infection Trephine biopsy stained with a Giemsa stain, showing faintly showing staining organisms within staining the foamy macrophages. macrophages Trephine biopsy in atypical Trephine mycobacterial infection (H & E) • Poorly formed granuloma Poorly composed of epithelioid composed macrophages, many of which have have vacuolated cytoplasm. vacuolated This infection is only likely to be detected on bone marrow examination of severely immunosuppressed individuals. individuals. Other opportunistic infections Other • Viral infections – CMV infection is common in AIDS • BM features are non specific, with atypical lymphocytes BM atypical and haemophagocytosis haemophagocytosis – Parvovirus B19 • This might lead to chronic red cell aplasia This chronic • There is disproportionate anaemia with reticulocyte count There close to zero close • BMA & TB show red cell aplasia and giant BMA proerythroblast. proerythroblast. • Confirmed by detection of viral DNA in the serum. Confirmed viral Other opportunistic infections Other • Fungal infections • Sometimes detected in BMA either within the Sometimes BMA macrophages or free macrophages • But more readily detected in the trephine But biopsy specimen. biopsy • A cryptococcal antigen test on the PB is a cryptococcal very good screening test for cryptococcosis, and PB cultures are often positive in HIV + pt PB with fungal infections; these tests may make marrow exam unnecessary. unnecessary Bone marrow aspirate in AIDS Bone showing Cryptococcus neoformans • Bone marrow aspirate in AIDS showing a budding form of Cryptococcus neoformans. Bone marrow aspirate in AIDS Bone showing Histoplasma capsulatum - Bone marrow aspirate in a patient with AIDS with histoplasmosis with showing histoplasma within a macrophage. within - Histoplasma are small yeast forms. yeast Other opportunistic infections Other • Parasitic infections – Leishmaniasis is usually readily detected in BMA & TB BMA – Toxoplasmosis – American trypanosomiasis – Rarely Pneumocystis carinii has been Rarely Pneumocystis detected in the BM of pt with AIDS. detected Leishmania donovani in a Leishmania monocyte • Blood film in a patient Blood with AIDS with showing Leishmania donovani in a monocyte. • Leishmania in circulating monocytes or neutrophils is rarely seen except in patients with AIDS. Lymphoproliferative disorders in AIDS in • The incidence of NHL is increased 60200 fold in pt with AIDS. • The incidence of HD may be increased The to 8-fold to NHL in AIDS patients NHL • The great majority are of B-lineage. The B-lineage • The strongest association is with The – Burkitt lymphoma – Burkitt like lymphoma – Large cell lymphoma of B-lineage • Persistant generalized lymphadenopathy often lymphadenopathy precedes the development of lymphoma and is indicative of increased risk of development of lymphoma. of HD in AIDS patients HD • It usually presents in patients in advanced It stage. stage • Often with B symptoms. Often • Bone marrow infiltration • The TB may be the initial or the only The diagnostic material. diagnostic • Histopathology often shows poor prognostic Histopathology types ( MC, or LD). MC, conclusions conclusions • HIV infection is associated with a great variety of HIV haematological abnormalities. haematological • HIV pt may have abnormalities due to drug therapy or HIV opportunistic infections. opportunistic • Diagnostic confusions specially with MDS can occur. • BMA & TB have a role in the diagnosis of BMA opportunistic infections and of lymphoma. opportunistic conclusions conclusions • Certain features are common although not Certain pathognomonic of HIV infection, but sufficient to suggest this diagnosis; – – – – – numerous bare megakaryocyte nuclei polymorphic lymphoid aggregates polymorphic gelatinous degeneration gelatinous detached nuclear fragments in granulocytes detached giant metamyelocytes in the absence of megaloblastosis. megaloblastosis. ...
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This note was uploaded on 12/24/2011 for the course STEP 1 taught by Professor Dr.aslam during the Fall '11 term at Montgomery College.

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