Diseases Test 2 Flashcards
Infusion reactions / cytokine release syndrome
Sx: chills, fever, arthralgia, diarrhea, vomiting, hypotension, respiratory distress.
Reaction to immunotherapy infusion.
HAMA (Human AntiMouse Antibody)
Hypersensitivity reaction plus kidney damage –> serum sickness.
Reaction to mouse based immunotherapy.
Sickle Cell Anemia
Point mutation (substitution of valine for glutamate) in Beta-chain. Results in aggregation and polymerization of blood cells upon deoxygenation.
Clinical findings:
- Blacks (8% are heterozygous)
- Severity of disease is variable
- Chronic hemolysis
- Vaso-occlusive disease
- Increased infection (autosplenectomy due to cyclical infarction and subsequent fibrosis) –> important for encapsulated organisms such as pneumococcus and haemophilus
- foot ulcers
Morphology:
Sickle cells
Post splenectomy blood : nucleated RBCs, targets, howell-jolly bodies, papenheimer bodies (tiny blue iron bodies), increased platelet count.
Rx: Prevent triggers (infx, fever, dehydration, hypoxemia), Vaccinate vs. encapsulated bugs, blood transfusions, bone marrow transfusions (especially children)
Thalassemia
Things you must know:
- Quantitative defect in Hg
- Can’t make enough either Alpha (can’t compensate) or Beta chains (can compensate)
- Variable severity
- Hypochomic, microcytic anemia with increased RBCs and target cells.
Normal hemoglobin: 4 alpha and 2 beta chains. Can have mutations in each gene of varying levels of effectivity. Correlates w/ disease severity from hydrops fetalis to asymptomatic.
Morphology:
- hypochromic, microcytic anemia
- anisocytosis and poikilocytosis varying w/ severity
- Target cells
- Basophilic stippling.
Clinical findings in alpha thalassemia:
- Asians, blacks
- Carrier state and thal trait: asymptomatic
- HbH disease: moderate to severe disease
- Hydrops fetalis
- medullary expansion (chipmunk face)
Clinical findings in Beta thalassemia:
- mediterraneans, blacks, asians
- thal minor: usually asymptomatic
- thal major: variable severity, usually presents in infancy
Glucose-6-Phosphate Dehydrogenase Deficiency
Things you must know:
- Decreased G6PD –> increased peroxides –> cell lysis
- oxidant exposure
- bite cells (removal of Heinz bodies)
- Self-limiting
Triggers: broad (fava) beans, drugs (sulfonamides, nitrofurantoin, aspirin, NSAIDS, quinine, anti-malarials
Sx: jaundiced sclera
Morphology: without exposure, no anemia, after exposure, get acute hemolysis (bite cells, fragments, Heinz bodies)
Higher in malaria endemic areas.
Microangiopathic Hemolytic Anemia
Things you must know:
- Physical trauma to red cells
- Schistocytes
- Find out why
Causes: Artificial heart valve, anything causing DIC, thrombotic thrombocytopenic purpura (TTP), or Hemolytic-uremia syndrome (HUS), marchers/runners anemia.
Disorder of small vessels.
Morphology: Schistocytes (fragmented, microcyted red cells with points on end), keratocyte (horn cell), triangulocyte (diagnostic), helmet cell, fibrin thrombi
Anemia of blood loss
Things you must know:
- Cause: traumatic, acute blood loss
- At first, hemoglobin is normal!
- After 2-3 days, see reticulocytes
- Chronic blood loss is different.
Anemia of chronic disease
Things you must know:
- infections, inflammation, malignancy
- iron metabolism disturbed (increased hepcidin –> abosrbtion is okay, but can’t get from macrophage to red cell)
- normochromic, normocytic
- anemia usually mild.
ddx of IDA vs AOCD: In AOCD, increased ferritin and marrow storage iron. Decreased TIBC (transferrin). Both have decreased serum iron.
Anemia of Renal Disease
Things you must know:
- End-stage renal failure
- Cause - lack of erythropoietin
- May see echinocytes
Clinical features:
End-stage renal disease. Anemia severity depends on kidney function. If severe replace erythropoietin.
Anemia of Liver Disease
Things you must know:
- Anemia is frequent in liver disease
- Multiple causes
- Often complicated cases
- May see acanthocytes, targets
Uncomplicated –> decreased RBC survival and impaired marrow response
Other factors can complicate picture:
- Folate deficiency
- Iron deficiency from frequent hemmorrhages (hemorrhoids)
Morphology: mild anemia, usually normocytic; sometimes macrocytic; poikilocytosis (targets, acanthocytes)
Clinical findings: 3/4 of liver disease pts are anemic. Alcohol abusers may get hemolytic episodes.
Aplastic anemia
Things you must know:
- Pancytopenia
- Empty marros
- Most are idiopathic
Causes: idiopathic, drugs, viruses, pregnancy, fanconi anemia
Clinical findings: pallor, dizziness, fatigue (anemia), recurrent infection (leukopenia), bleeding, bruising (thrombocytopenia)
Morphology: Blood empty; Bone marrow empty
Rx: avoid further exposure, give blood products, G-CSF, prednisone, anti-thymocyte globulin (ATG). Bone marrow transplant is last resort.
3 year survival = 70%
Type I Hypersensitivity
Seen in patients who make too much IgE to an environmental antigen, which is often innocuous like a pollen or food.
More than 10% of the population have allergenic sx
Usually a nuisance, but anaphylaxis can be fatal.
Genetic and environmental component.
Type II Hypersensitivity
Autoimmunity due to antibodies which can react against self.
Can come about from a number of ways:
- ) foreign antigen happens to look like a self molecule, the response can cross-react.
- )Antigen sticks to certain cells in the body. Immune system destroys innocent bystanders.
Ex: Hemolytic disease of newborn, myasthenia gravis, Good pasture’s syndrome
Type III Hypersensitivity
Can occur whenever someone makes antibody against a soluble antigen.
Small immune complexes become trapped in basement membranes or capillaries and activate complement. The usual inflammatory response occurs, with the tissue damaged as an innocent bystander.
No matter where the antigen is the symptoms tend to be the same: arthritis, glomerulonephritis, pleurisy, rash.
Examples of foreign antigens that cause type III are: large dose penicillin, antiserum (aka serum sickness). Also can be reactions to self such as SLE and RA.
I.e. Lupus and RA.
Type IV Hypersensitivity
Cell-mediated hypersensitivity caused by activated CD$ T cells. Can be autoimmune or more commonly innocent bystander injury.
I.e. Tuberculosis and hepatitis most damage is done by T cells, not the bacteria or viruses.
Examples: Contact hypersensitivity, Tuberculin rxn, Granulomatous hypersensitivity (macrophages wall off TB or Crohn’s)
X-linked agammaglobulinemia
Absence of B lymphocytes.
CD40 ligand deficiency
Failure of immunoglobulin class switching\
AKA hyper IgM syndrome.
Activation-Induced Cytidine Deaminase Deficinecy
Failure of immunoglobulin class switching
Common Variable Immunodeficiency
A failure to produce antibodies against particular antigens.
Omenn Syndrome
VDJ recombination failure. Cannot produce BCRs or TCRs.
X linked sever combined immunodeficiency
A failure to produce mature T lymphocytes
Digeorge syndrome
Failure of the thymus to develop correctly
Hemorphagocytic lymphohistiocytosis
Failure of CD8 T cells and NK cells to produce and/or release lytic granules
IPEX
A failure of peripheral tolerance due to defective Treg.