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
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
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
