DR.UNAIZA QAMARPROFESSOR DR.SAMINA NAEEM

TOPICS TO BE COVERED1. STRUCTURE AND FUNCTION OF HIV2. HIV & HEMATOLOGY-PATHOLOGY3. HIV & HEMATOLOGY-MORPHOLOGY

HIV STRUCTURE

HIV 1 & 2HIV-1 is a member of the primate Lentivirinae subfamily of

retroviruses RNA viruses Infection long periods of clinical latency followed by a

gradual onset of disease-related symptoms.

Transmission of Human Immunodeficiency Virus

Sexual TransmissionParenteral Drug UseInfected Blood ProductsMother-to-Child Transmission

Pathogenesis1) IMMUNODEFICIENCY 2) ABERRANT IMMUNE REGULATION

IMMUNE DEFICIENCY-Depletion of CD4+ T Cells1.the direct cytopathic effect of HIV. • 2 .The host immunologic response against HIV-infected

lymphocytes • 3.Formation of syncytial multinucleated giant cells• syncytia an aggressive clinical course.

ABERRANT IMMUNE REGULATION

Defects in B Cell ImmunitySpontaneous proliferation pronounced increase in

autoimmune phenomena and an increased risk of B cell lymphomas.

HIV---A VICIOUS CYCLE

Defects in Immune Accessory Cells and Natural Killer CellsMonocytes, macrophages, and follicular dendritic a chronic

reservoir of HIV expression a progressive depletion

Stages of HIV infectionCDCI CLASSIFICATION

CDC 1:Recently observerd illness(IM like symptoms)+seroconversion CDC 2:Well CDC 3:Well,With generalized lymphadeonpathy CDC 4: AIDS DEFINING ILLNESSA. Significant constitutional disease(weight loss,fever,diarrohea)B. NeurologicalC. InfectionsD. NeoplasmsE. Possible AIDS defining IllnessHIV +ve +CD4 <200/ul AIDS even without AIDS defining Illness

PATHOLOGY

HAEMATOLOGICAL

ASPECTS OF

HIV

The haematological features of HIV infection

Infection by the HIV and the consequent fully developed AIDS can have profound haematological effects inthe primary infection periodthe phase of clinical latency, andpatients with advanced disease

HIV---JUST AN INFECTION OF CD4???

NO!!!It starts with CD4 but would end up in affecting virtually all blood

cell lines and causing all sorts of diseases of BloodAnemiaMalignanciesAuto immune phenomenaImmuno deficient phenomena

RBCS AND HIV

HIV

Decreased red cell production

↓ CD34+ cellsBM INFILTRATION

INFECTIONNEOPLASMSDIRECT SUPPRESSION OF ERYTHROID ACTIVITY

Anemia of chronic disease

Blunted erythropoietin production

Iron deficiency anemia

Ineffective production

Folic acid deficiencyVitamin B12 deficiency

Increased red cell destruction

Coombs-positive hemolytic anemiaHemophagocytic syndrome

Thrombotic thrombocytopenic purpura

Medications

Consequences of Anemia in HIV Infection

Decreased Survival

HIV AND WBCS

Neutropenia

• MULTIPLE ETIOLOGIES 1.DECREASED PRODUCTION:• Decreased G-CSF• Infiltration• Medications 2.INCREASED DESTRUCTION:• presence of neutrophil-bound IgHypersplenism3.DEFECTIVE NEUTROPHILS

Patients tolerate neutropenia well at even ANC <500

HIV AND PLATELETS

Thrombocytopenia occurs much earlier than other manifestations of AIDS

Correlated to low CD4 count

THROMBOCYTOPENIA

HIV AND ITPDENOVO ITP HIV ASSOCIATED ITP

platelet-specific antibodies, 1.anti-glycoprotein (Gp) IIb 2.and/or GpIIIa

increased platelet destruction in the spleen.

cross-reactive antibody between

HIV Gp160/120 and platelet GpIIb-

IIIa (molecular mimicry )

Minimal activity against normal

platelets

Infection of Megakaryocytes by HIV

megakaryocytes bear a CD4 receptordirect infection of the megakaryocyte by HIVReduced

function.

HIV AND COAGULATION

HIVHYPERCOAGULABLE STATE

• increased TNF, IL-1, and IL-6increased levels of factor VIII and decreased levels of protein S, C

• down-regulate fibrionolysis• higher titers of anticardiolipin

HIV ANDHEMATOLOGICAL MALIGNANCIES

Human Immunodeficiency Virus-Associated Malignancies

> 40 % of all HIV-infected patients 3 Cancers if found in HIV + AIDS DEFINING ILLNESS(1) Kaposi’s Sarcoma (2) Diffuse large B cell lymphoma, (3) cervical carcinoma

Abnormal DNA Rearrangements

• c-myc Dysregulation

I. Burkitt’s Lymphoma• bcl-6 Dysregulation and Other Genetic Abnormalities• diffuse large-cell lymphomas• p53 mutations or deletions• ras have been described in some cases of AIDS-related Burkitt lymphoma.• Immunoblastic and large-cell lymphomas appear to be driven primarily by EBV.

FREQUENCY IN CONTRAST TO NON-HIV SUBJECTS:ALMOST 90% HIV+ PATIENTS HAVE HIGH GRADE

LYMPHOMAS (DLBCL,BL)

WHO CLASSIFICATION OF AIDS RELATED LYMPHOMAS

3 GROUPS (1) Those Occurring Specifically In HIV-infected Patients, (2) Those Also Occurring In Other Immunodeficiency States, And

(3) Those That Also Arise In Immunocompetent Patients.

Categories of HIV-Associated Lymphomas: World Health Organization Classification

• LYMPHOMAS ALSO OCCURRING IN IMMUNOCOMPETENT PATIENTS1. Burkitt lymphoma2. Diffuse large B cell lymphoma3. Peripheral T cell lymphoma (rare)4. Classic Hodgkin lymphoma• LYMPHOMAS OCCURRING MORE SPECIFICALLY IN PATIENTS WHO

ARE HIV POSITIVEa) Primary effusion lymphomab) Plasmablastic lymphoma of the oral cavityc) CNS Lymphoma

Burkitt Lymphoma In HIV

Atypical Burkitt’s lymphoma

plasmacytoid appearance termed Burkitt lymphoma with

plasmacytoid differentiation in the WHO classification,

an entity unique to patients with HIV

an oval nucleus, small but distinct nucleoli, and a modest amount of deep blue cytoplasm with prominent vacuoles.

Diffuse Large B Cell Lymphoma-AIDS Related(AIDS DEFINING)centroblastic immunoblastic1. BCL 6+2. NODAL

1. more typical of HIV infection. 2. CD 138+ Extranodal

These phenotypic differences suggest that the two variants have differing histogenesis, with the centroblastic subtype arising from germinal centers and the immunoblastic variant arising from postgerminal center lymphocytes.

DOUBLE HIT LYMPHOMAS

c-myc + bcl-2 rearrangements ("double-hit" lymphoma)

medium-sized cellwith several prominent nucleoli.

This lymphoma followed an aggressive course and was rapidly fatal.

LYMPHOMAS CHARACTERISTIC OF HIV:• PRIMARY EFFUSION

LYMPHOMA • HHV-8.

• large neoplastic cells• B lymphoid in origin• PEL is a CD30-ve ALCL

PLASMABLASTIC LYMPHOMA OF THE ORAL CAVITY,

• rapidly growing large lymphoid cells with marked plasma cell differentiation.

• They are positive for EBV • HHV-8 • poorly understood entity

Primary CNS Lymphoma

• An HIV patient presenting with seizures, headache, and/or focal neurologic dysfunction noted in most patients. Or in some cases just subtle changes in behavior.

• almost all such lymphomas are of diffuse large-cell or immunoblastic subtypes

• uniformly associated with EBV• Treated with HAART

T Cell Lymphoma

• a 15-fold increased risk • peripheral T cell lymphomas, 45%• anaplastic large cell lymphomas 27%

Hodgkin Lymphoma in the Setting of HIV Infection

an 8- 10-fold increased risk of developing HL than expected in the general population

• one of the most common cancers in HIV-infected patients. • non–AIDS-defining• ALMOST ALL CASES ARE EBV ASSOCIATED• Mixed cellularity and Lymphocyte Depleted are common

Clinical Features

HIV SUBJECTS NON-HIV SUBJECTS

• B symptoms and marrow infiltration in 80 to 90 %,

• 61 to 90 %extranodal sites. • Virtually any anatomic site may be

involved.• Lumbar puncture should routinely

be performed

30-40%

40%

LP not needed

HEMATOLOGIST AND HIV

Diagnostic confusionHematologists should be aware.HIV infection can simulate the:

MDSMPD, Megaloblastic anemia andT-cell lymphoma

PERIPHERAL BLOOD

General haematological features of AIDS

Peripheral bloodasymptomatic period

↓ CD4 + ↑ CD8 lymphocytes

By the time of diagnosis there is Lymphopenia Often pancytopenia Anaemia usually normochromic, normocytic

sometimes macrocytic.

Peripheral blood changesRed cell changes increased background staining

Anisocytosis, poikilocytosis, rouleaux formationOccasionally the blood film shows features of

MAHA

Peripheral blood changes

Neutrophils may show dysplastic features: toxic granulation Dohle bodiescytoplasmic vacuolation left shiftpresence of detached nuclear fragmentshypogranularity and occasional Pelger forms

Neutrophil with a detached nuclear fragment in AIDS

a detached nuclear fragment can be seen in AIDS patients

Peripheral blood changes

Thrombocytopenia , normal size platelets.Except when there is immune destruction,

large size platelets may be seen.

BONE MARROW ASPIRATE

Why to Do?CulturesStaging/diagnosisElucidating cytopenias

Bone marrow aspirate

Hypercellullar Hypocellular

Trilineage dysplasia is common.Difficult to aspirateTrails of decreased cellularity

Bone marrow aspirate

ERYTHROPOEISIS:Florid Megaloblastosis(unrelated to B12 FA

levels).Occasional ring sideroblastsNuclear lobulation and fragmentationBi- and multi-nuclearityCytoplasmic bridgingCytoplasmic vacuolationBasophilic stipplingHowell-Jolly bodies

Bone marrow aspirate

MYELOPOIESIS:Dysplastic changesGiant metamyelocytes are common even in the

absence of megaloblastic erythropoiesis.Pelger huet neutrophils

Giant metamyelocyte

A hypogranular giant metamyelocyte in the peripheral

blood of a patient with AIDS.

Bone marrow aspirate

MEGAKARYOPOEISIS:Early Stagesincreased decreased in the later stages.They show dysplastic features

Bizzare nuclear shapes Hyperchromatic nuclei Nuclear hypolobulation

Bone marrow aspirate

Reactive changes include:Increased lymphocytesIncreased plasma cells_reactiveIncreased macrophagesHaemophagocytic syndrome

Differences between HIV and MDS in the BMA

In HIVRing sideroblasts are not a

prominent featureMyeloblasts are not increasedMicromegas are not commonAuer rods are not seen

In MDSGiant metamyelocytes

(common in AIDS) are quite uncommon in MDS.

DYSPLASIA IN HIV IS NOT A PRELEUKEMIC STAGE

Dysplastic and Reactive bone marrow

BONE MARROW TREPHINE BIOPSY

Bone marrow trephine biopsy

Initially HPERCELLULARMyeloid and megakaryocytic hyperplasia.Megakaryocytes are clustered and dysplasticIncreased number of bare megakaryocyte nuclei.

Bone marrow trephine biopsy in AIDS showing dysplastic megakaryocytes (H & E)

The megakaryocytes are hypolobulated and clustered.

Bone marrow trephine biopsy

Reticulin is often increased.Later hypocellular gelatinous degeneration necrosisMay show BM granulomas.Lymphomatous infiltration

A random focal lymphoid infiltrate (H & E)

A random focal lymphoid infiltrate

Something seen in as many as 1/3rd of the TB in AIDS

Reactive benign nodules

OPPORTUNISTIC INFECTIONS AND BONE MARROW

Specific infections in AIDSOpportunistic infections very common in

AIDS, Mycobacterial and other bacterial

infectionsMycobacterium tuberculosisAtypical mycobacterial infectionMycobacterium avium intracellulare

well-formed, or less formed granulomas.Caseation may occur in tuberculous granulomas.foamy macrophagesCulture for mycobacteria is obligatory PUO

Trephine biopsy in atypical

mycobacterial infection

Trephine biopsy stained with a Giemsa stain, showing faintly

staining organisms within the foamy macrophages.

Trephine biopsy in atypical mycobacterial infection (H & E)

Poorly formed granuloma composed of epithelioid

macrophages, many of which have

vacuolated cytoplasm.

Other opportunistic infectionsViral infections

CMV BM features are non specific

Parvovirus B19

Other opportunistic infectionsFungal infectionsSometimes detected in BMA(macrophages

or free)readily detected in trephine biopsy

Bone marrow aspirate in AIDS showing Cryptococcus neoformans

BMA showing a budding form of Cryptococcus neoformans.

Bone marrow aspirate in AIDS showing Histoplasma capsulatum

- histoplasma within a

macrophage. - small yeast forms.

Other opportunistic infectionsParasitic infections

Leishmaniasis is usually readily detected in BMA & TB

ToxoplasmosisAmerican trypanosomiasis

Leishmania donovani in a monocyte

Leishmania donovani in a monocyte.

Leishmania in circulating monocytes or neutrophils IS RARELY seen except in patients with AIDS.

conclusion

CONCLUSIONS:Certain features are common although not

pathognomonic of HIV infection, but sufficient to suggest this diagnosis; numerous bare megakaryocyte nuclei polymorphic lymphoid aggregates gelatinous degeneration detached nuclear fragments in granulocytes giant metamyelocytes in the absence of

megaloblastosis.