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.
Heriditary Angiodema (HAE)
Caused by a C1 Inh Deficiency
Recurrent episodes of localized edmea in skin, GI tract, or larynx.
C1 inhibitor
- inhibits C1 esterase
- also inhibits MASP, Kallikrein, plasmin, factor XIa and Factor XIIa
- uncontrolled complement activation leads to consumption of C4 and C2.
Prevalence: 2-10 per 100,000
Rx: Steroids to increase C1 INH synthesis, purified C1 INH, kallikrein inhibitors and B2 receptor inhibitors.
Deficiency in DAF (CD55) and CD59
Increased susceptibility of erythrocytes to MAC-medicated lysis.
Complement mediated hemolysis in paroxysmal nocturnal hemoglobinuria (PNH)
Rx: w/ antibody to C5 (eculizumab) reduces hemolysis.
Whole Blood
Contents: RBC, WBC, platelets, plasma
Use: massive hemorrhage
Red Cells
Contents: RBC, a few WBC, a few platelets, a little plasma
Use: low hemoglobin
Leukocyte-Reduced Red Cells
Contents: RBC, no WBC, rare platelets, a little plasma.
Uses: decrease alloimmunization, decrease allergic reactions
Frozen Red Cells
Contents: RBC and a few WBCs
Use: Storage or rare blood types
Granulocytes
Contents: neutrophils
Use: sepsis in neutropenic patients
Platelets
Contents: platelets
Use: bleeding due to thrombocytopenia
Fresh Frozen Plasma
Contents: Plasma (including all coagulation factors)
Use: bleeding due to multiple factor deficiencies (DIC)
Cryoprecipate
Contents: fibrinogen, von willebrand factor, VIII, and XIII
Use: low fibrinogen, vW disease, hemophilia A, XIII deficiency
VIII
Use: Hemophilia A
IX
Use: Hemophilia B
Albumin
Use: hypovolemia with hypoproteinemia
IvIG
Use: disease prophylaxis, autoimmune disease, immune deficiency states.
Forward Type
Patient red cells and add anti-A antibodies and monitor for agglutination (positive test).
Done w/ both anti-A and anti-B antibodies
Reverse Type
Patient serum and reagent red cells.
Monitor for agglutination
Reverse typing is done using both type A and type B reagent cells.
Crossmatch
Patient serum plus donor RBC.
Monitor for agglutination.
Acute Hemolytic Transfusion Reactions
Happen when patient has ABO antibodies against the donor red cells.
Most common reason: clerical error!
Symptoms: fever, chest pain, hypotension.
Hemoglobin in serum, urine.
Labs: decreased haptoglobin, increased bilirubin, DAT positive.
Type and cross-match shows ABO mismatch.
Delayed Hemolytic Transfusion Reactions
Hemolysis occurs days after tranfusion.
Caused by antibodies to non-ABO antigens.
Hemolysis usually extravascular.
Presentation: falling Hgb after transfusion.
Usually not severe.
DAT +. Antibody screen identifies the antibody.
Febrile Transfusion Reactions
Caused by recipient antibodies against donor WBC.
Cytokines → fever, headache, nausea, chest pain.
Diagnosis: rule out everything else
Treatment: Tylenol. Leukocyte-reduced components.
Allergic Transfusion Reactions
Probably a host reaction to donor plasma proteins
Symptom: hives
Treatment: antihistamines
Rarely, reaction is severe (anaphylaxis)
Circulatory overload
Happens when too much blood is given too quickly
Symptoms: hypertension, congestive heart failure
Stop transfusion, give diuretics
Iron Overload
Too much iron can damage heart, liver
Patients with chronic anemias are at biggest risk
Give iron-chelating agents
Graft vs. Host Disease
Donor lymphocytes attack host.
Immunocompromised patients, or patients with blood-relative donors.
Fever, rash, hepatitis, marrow failure.
Usually fatal.
Prevent by irradiating products.
Mature Neutrophilia
A lot of segmented neutrophils
Seen in 3 states:
- ) Infection
- ) Inflammation
- ) Physiological stress and hormones
Toxic changes seen only in infection. (toxic granulation, dohle bodies, cytoplasmic vacuolization.
Immature Neutrophilia
Caused by infx, inflammation, severe anemia (look for accompanying immature RBCs, or something (i.e. cancer) filling up the marrow.
Three forms:
Left shift (fewer mature nphils)
Leukomoid reaction (outdated term)
Leukoerythroblastotic reaction - lots or RBCs and WBCs. Worrisome if patient isn’t anemic.
Lymphocytosis
Normal lymphocyte count varies a lot with age w/ infants and youth having much higher amounts.
Normal immunophenotype in blood:
- T cells 80%
- B cells 15%
- NK cells 5%
These percentages are important to determine if lymphocytosis is due to overproduction (infx) vs. malignancy (i.e. multiple myeloma)
Types:
Mature - infectious lymphocytosis, bordetella pertussis, and transient stress
Reactive- Infectious mononucleosis, pediatric viral infections, viral hepatitis, and immune disorders. (see Downey cells = fried egg w/ radial striations)
Chronic Myeloid Leukemia
Characterized by:
- Super-high WBC
- Lots of immature cells
- Basophilia (KEY, Only thing you think of w/ basophilia)
- Leukocyte alkaline phosphatase (enzyme in normal leukocytes) decreased
Best dx is w/ cytogenetics. Look for philadelphia chromosome translocation of 9:22
Chronic Lymphocytic Leukemia
Characteristics:
- Mature lymphocytes
- Monomorphic
- Only old people (>40)
Immunophenotyping is gold standard. CLL will have way too many B cells.
DDx vs: Reactive lymphocytosis (atypical lymphocytes and
Eosinophilia
Due to:
- Drug rxn
- Asthma
- Skin diseases
- Parasites (often on boards, but often not true in real life)
Monocytosis
Due to:
- Infection
- Autoimmune disease
- Malignancy (paraneoplastic form solid tumor)
Hemolytic Disease of Newborn (erythroblastosis fatalis)
Hemolysis in a newborn or fetus caused by blood-group incompatibility between mother and child.
Mech of disease:
- )Baby inherits blood group Ag (from dad) that are foreign to mom
- ) Baby’s blood gets into mom’s circulation (i.e. placental abruption)
- ) Mom makes Ab to baby’s blood group Ag (IgM then IgG)
- )Mom’s ab attack baby’s RBC (often a later pregnancy)
Consequences:
- extramedullary hematopoiesis
- heart and liver failure
- hydrops fetalis
- jaundice
- kernicterus (brain damage due to high levels of bilirubin)
Dx and prevention:
- Dx w/ DAT (baby) and IAT (mom)
- Give Rhogam (anti-D Ab) at 28 weeks and within 72 hours of delivery
- Must quantify amount of fetomaternal hemorrhage to dose Rhogam; use Kleihauer-Betke test or flow cytrometry
ABO Incompatability
Occurs in 25% of pregnancies, but only severe in 1 in 200 cases (1:1000 incidence)
Most anti-A and anti-B Antibodies are IgM (can’t cross)
Neonatal RBCs express A and B poorly
There’s no effective protection vs. ABO-mediated HDN
Treatment:
Mild cases: phototherapy
Severe cases: total exchange transfusion, mom can undergo plasmapheresis, high-dose IvIG
Ascites
Large amount of fluid accumulation in abdominal cavity. Can cause shortness of breath and abdominal pain.
Main causes: Liver failure/cirrhosis/cancer (hypoproteinemia), malnutrition (hypoproteinemia), CHF, or tumor.
Rx: furosemide, paracentesis (and catheter placement)
-Be careful w/ paracentesis due to large volume of fluid leaving causing intervascular fluid to follow resuliting in hypovolemic shock.
Congential methamoglobinemia
Patients appear cynotic, but have few clinical problems
Excess methemoglobin due to a def. in cytochrome b5 reductase
Acquired Methemoglobinemia
Caused by ingestion nof certain oxidants such as nitrites, quinones, aniline, and sulfonamides.
Can be related to benzocaine, lidocaine, dapsone use.
Rx: adminstration of reducing agents such as ascorbic acid or methylene blue.
Glucose 6 phosphate dehydrogenase (G6PD) deficiency
Enzyme that catalyzed first step of the pentose phosphate pathway.
As G6PD activity decreases, oxidative damage accumulates, leading to lysis of the RBC.
Most common enzyme deficiency in humans (over 400 million people worldwide)
X-linked disease
Severity depends on mutation (varies widely)
Resistant to malaria
Hemolytic anemia following oxidative stressor such as: anti-malarials, sulfonamides, nitrofurantoin, and fava beans.
Peripheral smear: heinz bodies, bite cells, blister cells
Sx: dark urine, pale skin, weakness, jaundice, hepato/splenomegaly, tachycardia, and fever.
Hereditary Spherocytosis
Inherited hemolyic anemia that is most common in Northern Europeans.
Ankyrin deficiency is most common. Spectrin, or both are also deficient in some cases.
Membrane and underlying structural proteins are disjoined and cells become spherocytes.
Clinical features:
- Anemia, Jaundice, Splenomegaly
- May present at any age, severe in neonates
- Can be precipitated by illnesses that cause splenic hypertrophy and by long term intense physical activity.
Dx w/ spherocytes and reticulocytes. Eleveated indirect bilirubin. Negative DAT. Incubated osmotic fragility test.
Can have crisis events after triggers (i.e. parvovirus, mono)
Rx: splenctomy, folate supplementation
