1) HIV is a retrovirus that causes AIDS by infecting CD4+ T cells and macrophages. It has an outer envelope with glycoproteins gp120 and gp41, and an inner capsid core containing its RNA genome and enzymes. 2) HIV enters cells via gp120 binding to CD4 and CCR5 receptors, then replicates by transcribing its RNA into DNA. New virions bud from the cell membrane. 3) Primary HIV infection causes flu-like symptoms. Later, without treatment, opportunistic infections and cancers develop due to immune deficiency, defining AIDS.

1. Topic- Pathophysiology Of AIDs
BY
49- Shambhavi Nade
50- Abhishek Kembave
51- Parth Zirange
Under the Guidance of
Asst.Profesor Miss Anuradha Deshmukh

2. Human immunodeficiency virus
HIV is a lentivirus (a subgroup
of retrovirus) that causes HIV
infection and over time
acquired immunodeficiency
syndrome (AIDS)

3. Structure
• It is roughly spherical
• diameter of about 120 nm
• composed of two copies of positive-sense single-stranded RNA
• RNA codes for the virus's nine genes enclosed by a conical capsid composed of
2,000 copies of the viral protein p24
• RNA is tightly bound to nucleocapsid proteins- p7
• enzymes needed for the development of the virion such as reverse transcriptase,
proteases, ribonuclease and integrase are also present.
• A matrix composed of the viral protein p17 surrounds the capsid ensuring the
integrity of the virion particle
• A lipid viral envelope is present that composed of proteins like gp41 and gp120

4. Structure

5. Classification
• the International Committee on the Taxonomy of
Viruses (ICTV) as two separate families —
Papillomaviridae and Polyomaviridae.
• HPV is divided into High risk HPV and Low risk HPV. Low-
risk types cause warts and high-risk types can cause
lesions or cancer.

6. Pathogenesis
• HIV can infect immune cells such as CD4+ T cells,
macrophages, and microglial cells.
• HIV-1 entry to macrophages and CD4+ T cells is
mediated through interaction of the virion envelope
glycoproteins (gp120) with the CD4 molecule on the
target cells' membrane
• also with chemokine co-receptors – CCR5

7. Multiplication

8. Multiplication steps
Entry:
• The virion enters cells by the adsorption of gp on its surface to receptors (CD4,
CCR5) on the target cell
• followed by fusion of the viral envelope with the target cell membrane
• the release of the HIV capsid into the cell
Replication and transcription:
• reverse transcriptase liberates the positive-sense single-stranded RNA genome
from the attached viral proteins and copies it into a complementary DNA
(cDNA) molecule
Assembly and Release:
• The final step of the viral cycle, assembly of new HIV-1 virions, begins at the
plasma membrane of the host cell.

9. Multiplication steps
• The classical process of infection of a cell
by a virion can be called "cell-free
spread“
• In cell-free spread , virus particles bud
from an infected T cell, enter the blood
or extracellular fluid and then infect
another T cell following a chance
encounter.
• HIV can also disseminate by cell-to-cell
spread,

10. Symptoms
Primary HIV infection
• often is mistaken for influenza or a bad cold - reported by roughly half of those who
contract HIV
• generally occurs between 2 and 6 weeks after infection
• Symptoms may include fever, headache, sore throat, fatigue, body aches, weight loss,
and swollen lymph nodes. Neurological symptoms of peripheral neuropathy
• Other symptoms are a rash, mouth or genital ulcers, diarrhea, nausea and vomiting, and
thrush. Gastrointestinal symptoms, such as vomiting or diarrhea may occur
• The CD4+ T cell count can drop very low during the early weeks
• The initial illness can last several days or even weeks.
• The greatest spread of HIV occurs throughout the body early in the disease.

11. Symptoms
Latency period
• After initial infection comes the latency period, or incubation period
• period lasts a median of about 10 years.
• The most common symptom is lymphadenopathy, or swollen lymph
nodes.
• The lymph nodes of arms, neck, groin area

12. Symptoms
Acquired immunodeficiency syndrome (AIDS)
• defined in terms of either a CD4+ T cell count below 200 cells per µL or the
occurrence of specific diseases in association with an HIV infection.
• develop AIDS within ten years.
• most common initial conditions are pneumocystis pneumonia, cachexia in
the form of HIV wasting syndrome, and esophageal candidiasis and
recurrent respiratory tract infections
• increased risk of developing various viral-induced cancers, including
Kaposi's sarcoma, Burkitt's lymphoma, primary central nervous system
lymphoma, and cervical cancer.

13. Symptoms
Pulmonary
• Pneumocystis pneumonia (PCP) caused by Pneumocystis jirovecii a yeast like
fungus
• Tuberculosis (TB)
Gastrointestinal
• Esophagitis is an inflammation of the lining of the lower end of the esophagus
• Unexplained chronic diarrhea (Salmonella, Shigella, Listeria or Campylobacter)
Neurological
• Toxoplasmosis is a disease caused by the single-celled parasite called
Toxoplasma gondii
• demyelinating disease, in which the gradual destruction of the myelin sheath
covering the axons of nerve cells impairs the transmission of nerve impulses
(by JC virus)
• Dementia
Tumors
• Kaposi's sarcoma (KS) is the most common tumor in HIV-infected patients
• Lymphoma, cervical cancer, hepatocellular carcinoma

14. Transmission
• Only certain body fluids—blood, semen, pre-seminal fluid, rectal fluids,
vaginal fluids, and breast milk
• from a person who has HIV can transmit HIV.
• These fluids must come in contact with a mucous membrane or
damaged tissue
• or be directly injected into the bloodstream (from a needle or syringe)
for transmission to occur.
• Mucous membranes are found inside the rectum, vagina, penis, and
mouth.

15. Transmission
• Sex without a condom:
having unprotected sex with someone who has HIV, particularly unprotected vaginal sex and anal
sex.
• Sharing injecting equipment:
sharing needles, syringes or other equipment used to prepare and inject drugs with someone who
has HIV.
• Passed from mother-to-baby during pregnancy, childbirth and breastfeeding
a mother infected with HIV can pass the virus to her baby via her blood during pregnancy and
birth, and through her breast milk when breastfeeding.
• Contaminated blood transfusions and organ/tissue transplants
receiving blood transfusions, blood products, or organ/tissue transplants that are contaminated
with HIV. This risk is extremely small because most countries test blood products for HIV first.

16. Diagnosis:
Common diagnosis methods are ELISA testing, but has to be confirmed by
PCR
or NAT or Western blot
• ELISA testing
• Western blotting
• nucleic acid testing (NAT)
• Polymerase chain reaction

17. Treatment
• Once treatment is begun it is recommended that it is continued without
breaks
• treatment with antiretrovirals reduces the risk of developing additional
opportunistic infections
• Dietary intake of micronutrients
• higher intake of vitamin A, zinc, and iron can produce adverse effects in HIV
positive adults, and is not recommended unless there is documented
deficiency

18. Refernece-