Week 4 Flashcards
What is systemic lupus erythematosus?
An autoimmune disease that can affect any tissue or organ in the body, but most often affects the skin, kidneys, and joints
What is the cause of systemic lupus erythematosus?
It is unknown, but it occurs as a result of genetics and the environment
____ is an environmental risk factor for lupus
UV radiation/sunlight is an environmental risk factor for lupus
____ are present in in the body in almost all cases of lupus
Antinuclear antibodies are present in the body in almost all cases of lupus
Antigens and antibodies bind to another in the body in a case of lupus to create an antigen-antibody complex. After binding together, what do they do?
They get into the blood, drift away, and deposit/stick to the vessel wall in all organs and tissues
What are the organs and tissues that antigen-antibody complexes stick to their vessel walls?
- Kidneys
- Skin
- Joint
- Heart
Antigen-antibody complexes that deposit/stick to the vessel walls of organs and tissues lead to what?
The initiation of local inflammatory reactions
What chain of events is caused by the initiation of local inflammatory reactions, as caused by the antigen-antibody complexes that deposit/stick to the vessel walls of organs and tissues?
The initiation of local inflammatory reactions causes damage to the activation of the complement system, which after a huge cascade of enzyme activation, leave cell membrane with channels that let food and molecules pass through with no problems, causing the cell to burst and die
What is a type 3 hypersensitivity reaction?
When there is tissue damage that occurs as a result of immune complexes
What are the other potential triggers that has been associated with lupus?
- Cigarette smoking
- Viruses
- Bacteria
- Use of certain medications, like procainamide, hydralazine, and isoniazid
- Sex hormones, particularly estrogen
True or False
Lupus is more common in women
True, lupus is more common in women due to estrogen being a trigger. Hence why it is more common in women during reproductive years, than it is during non reproductive years
What is a type 2 hypersensitivity reaction?
When antibodies target red and white blood cells, and molecules like phospholipids, which can mark them for phagocytosis and destruction, which leads to additional symptoms of lupus
What is the classic presentation of lupus?
- Fever
- Joint pain
- Rash
In a woman of childbearing age
Why is the diagnosis of lupus difficult?
It can affect a wide variety of people and has a wide variety of symptoms
What are the general symptoms of lupus?
- Fever
- Weight loss
What are the specific symptoms of lupus based on?
It is based on the organ/tissue being affected
When is a diagnosis of lupus given to a person?
Only when 4 or more of the 11 diagnostic criteria is met
What are the diagnostic criteria for lupus?
- Malar rash: a rash on the cheek that spares the nasal, labial folds. Also called a butterfly rash
- Discoid rash: plaque like, chronic rash found in sun exposed areas that can form a sort of patchy redness and scar
- General skin photosensitivity: other rashes from sun exposed areas that typically last a couple of days
- Ulcers in the mucous(inner) membranes of the mouth, and nose
- Serositis which is the inflammation of the outer membrane of a cell and can lead to: pleuritis which is inflammation of the lining around the lungs or chest cavity. Or pericarditis: inflammation of the lining of the heart
- Arthritis of 2 or more joints
- Renal disorders like: abnormal amounts of urine protein, diffuse proliferative glomerulonephritis(inflammation of the glomeruli)
- Neurological disorders like seizures and psychosis
- Hematologic disorders: Anemia if RBCs are affected, thrombocytopenia if platelets are affected, leukopenia if WBCs(immune cells) are affected
- Presence of antinuclear antibodies(very sensitive, but not specific, bcos it is seen in other diseases)
- Other autoantibodies like, anti-smith which targets ribonucleoproteins, anti-dsDNA which targets double stranded DNA and is often seen during periods of active disease, and anti-phospholipid which targets protein that are bound to phospholipids
What other parts of the heart can lupus affect?
- Endocardium: which presents as libman-sacks endocarditis, where vegetations(made up of fibrin and immune cells) form on the mitral valve
- Myocardium
What are the types of other autoantibodies that are specific to lupus?
- Anti-smith which targets ribonucleoproteins
- Anti-dsDNA which targets double stranded DNA and is often seen during periods of active disease
What are the types of anti-phospholipids?
- Anticardiolipin: can cause a false positive for syphilis
- Lupus anticoagulant
- Anti beta2 glycoprotein 1
What is anti-phospholipid syndrome?
Where anti-phospholipid antibodies cause a hyper-coagulable state, meaning that they are more prone to developing clots and complications like DVTs, hepatic vein thrombosis, and a stroke
What do patients with anti-phospholipid syndrome end up needing?
Lifelong anticoagulant therapy
What is lupus characterized by?
Periods of flare ups and remittance
What is the treatment of lupus often aimed at?
Preventing flare ups or limiting their severity
What are some ways that may help prevent lupus flare ups?
Avoid sunlight
What are some ways that may help limit the severity of lupus flare ups?
- The use of corticosteroids to help limit immune responses
- The use of immunosuppressants when flare ups are really severe
What is HIV?
A type of virus that infects human immune cells. Over time, immune cells are lost, which weakens the immune system and allows patients to be infected by other viruses and develop several types of tumors
What is AIDS?
Acquired immuno-deficiency syndrome, which are the viruses and tumors that is acquired after the immune system weakness has been developed
What type of HIV is more commonly associated with AIDS in the US and worldwide?
HIV-1
What type of HIV is more commonly associated with AIDS in the western Africa and southern Asia?
HIV- 2
What type of HIV is the most uncommon?
HIV- 2
What type of cells does HIV target?
CD4+cells on them
What types of cells have CD4+cells on them?
- T helper cells
- Macrophages
- Dendritic cells
What is the role of CD4 on cells?
It helps immune cells communicate, and are particularly important for when they are launching attacks on pathogens
How does HIV cells attach to CD4?
Via a protein called gp120
What does HIV need to attach to before it can get inside a cell?
It has to attach to BOTH the CD4 molecule and the co-receptor
What is the most common co-receptor that HIV uses?
- CXCR4 co-receptor, which is found mainly at T-cells
- CCR5 co-receptor, which is found on T-cells, macrophages, monocytes and dendritic cells
What are the things that can make the spread of HIV difficult?
- Homozygous mutation, which makes co-receptors resistant or immune to attachment
- Heterozygous mutation, which can result in a slower disease progression
What kind of cell is HIV?
A single stranded, positive sense, enveloped RNA retrovirus
What is the mechanism of the action of HIV?
It injects its single stranded RNA into the T-helper cell, and it needs to use the enzyme, reverse transcriptase, to transcribe a complementary double stranded piece of proviral(ready to be integrated into the host’s DNA) DNA. The new strand enters the T-helper cell nucleus, and inserts itself into the cell’s DNA and is ready to be transcribed into new viruses
During replication, DNA cells are prone to making errors. What does this lead to?
It leads to different strains of the virus being created in the body, and they target different cells, which is called viral tropism
What strain of HIV binds to the CCR5 co-receptor?
R5 strain
What type of symptoms do patients typically experience during the acute phase of HIV?
Flu- like symptoms
At which point does a patient enter into the chronic or clinically latent phase of HIV?
At 12 weeks
How long does the chronic or clinically latent phase of HIV last?
2- 10 years
As the HIV virus increases in the body during the chronic phase, what happens to the amount of T-cells?
It decreases
What types of infections become more common and severe in patients with HIV?
Tuberculosis
During the chronic phase of the HIV infection, some patients develop a X4 strain of HIV. What does it do?
The X4 strain of HIV targets the CXCR4 co-receptor, which is essentially only T-cells. The X4 strain of HIV lays low in the lymphoid tissues and steadily destroy T-cells.
What happens when a patient’s T-cells have dropped to 200-500 Tcells/mm?
- Swollen lymph nodes (lymphadenopathy)
- Hairy leukoplakia(white patch on the tongue caused by epstein barr virus, that causes mono-nucleosis)
- Oral candidiasis (yeast infection in the mouth)
What happens when a patient’s T-cells is below 200 Tcells/mm?
- Immunse system is severely compromised
- Disease has progressed from HIV to AIDS
- Persistent fever
- Fatigue
- Weight loss
- Diarrhea
- Significant increase in HIV content of the blood
What are the AIDS defining conditions that occur once a patient’s T-cells is below 200 Tcells/mm?
- Recurrent bacterial pneumonia
- Pneumocystis pneumonia
- Fungal infections like candidiasis of the esophagus
- Tumors and malignancies like kaposi sarcoma(lesions of the skin and other soft tissue), and primary lymphoma of the brain
___ is the most common transmission of HIV in the US
Male to male is the most common transmission of HIV in the US
___ is the most common transmission of HIV in resource limited settings
Male to female is the most common transmission of HIV in resource limited settings