Pathology Flashcards
T/F: In severe illness such as a heart attack, pneumonia, etc, we should work the patient up for diabetes.
FALSE!!!!
Stress of illness often raises glucose to high levels. DO NOT work up for diabetes!
Bilirubin is a _____ function test.
liver
______ is derived from aging and circulating RBC’s, less so from ineffective erythropoiesis and the turnover of other heme‐rich cells (including hepatocytes)
Bilirubin
Increased indirect bilirubin may indicate what? (5)
- MC: hemolysis
- Common in newborns due to immature livers, hemolysis from ABO Ab
- Sickle cell and spherocytosis pts (have mild lifetime jaundice)
- Gilbert’s syndrome (fasting increases it more)
- Rifampin
- Trauma pts: reabsorpt. of hematoma; Medical pts: reabsorpt. of a hemorrhage w/in a lung infarct
These “liver function tests” reflect liver disease or obstruction / cholestasis rather than liver function. Interpret with caution and insight! What are they? (4)
- AST
- ALT
- Alkaline phosphate
- LDH
LDH (LD) is found in all tissues and increased values suggest nonspecific disease (ex: tumor marker for some germ cell cancers)
-HIGHEST LDH’s are in what? (2)
- infectious mononucleosis
- megablastic anemias (intramedullay hemolysis)
What can affect the serum potassium? and therefore it is critical to draw the specimen properly and be aware of this when interpreting the results.
Any hemolysis!
When is the anion gap decreased?
- multiple myeloma (cationic paraprotein)
- hyponatremia, hypoalbunemia
- bromide ingestion (anion)
What is synthesized in the liver by macrophages and fat cells in response to inflammation? What is it useful in determining?
High sensitivity C-reactive Protein
heart disease/cardiovascular risk
Leukocytes (WBC) polymorphonuclear cells (granulocytes) include what types of cells? (3)
- neutrophils (segmented nucleus)
- basophils (dark blue granules)
- eosinophils (bilobed nuclei)
What do blasts (even just 1) indicate if seen in the peripheral blood?
Disease!!! (immature cells of undifferentiated lineage)
In adults, what is the reasonable range value for healthy WBC/mcL?
4500-11,000 WBC/mcL
17,000 for a three‐year old and 13,000 for a teen are reasonable upper limits
What are the two types of agranulocytes (mononuclear cells) considered WBC?
- lymphocytes
- monocytes (macrophages outside the bloodstream)
TQ: A value of 8000 neutrophils/mcL is called…..
neutrophilia
an absolute neutrophil count above the top of the reference range
TQ: A value of 2500 neutrophils/mcL is called…..
Neutropenia
serious infection is likely only with counts below 1000/mcL and grave danger only with counts below 500/mcL
Neutrophilic bands are immature neutrophils. The presence of more than a few immature neutrophils in the peripheral blood is called what?
a left shift
Increased eosinophils (greater than ___/mcL) may be due to what?
600mcL
- meds
- parasitic infx
- Asthma
- Hodgkin’s dz
- Churg-Strauss!!!
- Addison’s
- higher in afternoon due to circadian rhythym of cortisol
T/F: Pt’s with allergic or atopic disorders such as hay fever or other mild allergies don’t have elevated eosinophils
TRUE
What is the reasonable reference range of lymphocytes for adults?
800-4800/mcL
higher in children and teens
Activated lymphocytes such as atypical lymphocytes are found in what?
Depletion of CD4 cells is found in what?
infectious mononucleosis
HIV
Are WBC lymphocytes increased or decreased in whooping cough?
increased
What is the reference range for monocytes?
up to 900 mcL, 1200 for kids
What is the volume of RBC to volume of whole blood called?
Hematocrit
What are the reference ranges for hematocrit of an adult man and woman?
39-50% for men
35-46% for women
In what conditions would RBC count be decreased? (4)
- anemia
- microcytic normochromic
- normochromic normocytic
- macrocytic anemia.
In what conditions would RBC count be increased? (3)
- polycythemia vera
- secondary polycythemia
- vigorous exercise.
At what mean cell volume do most hemolytic anemias fall?
80-100 (normal range…normocytic)
What is the mean cell volume for macrocytic diseases such as megaloblastic anemia?
Normocytic?
Microcytic (iron deficiency and thalassemias)?
> 100 macrocytic
80‐100 normal range, normocytic
< 80 microcytic
______ anemias lack hemoglobin. The red cell tends to be pale and small because the RBC precursor cannot make enough hemoglobin
Hypochromic
What are some examples of hypochromic anemias? (3)
- Iron deficiency
- Thalassemia
- Severely defective porphyrin synthesis
What is increased in hereditary spherocytosis? (membrane fragments are lost so the hemoglbin is more dense and stains purply)
MCHC (Mean corpuscular hemoglobin concentration…a measure of the concentration of hemoglobin in a given volume of packed red blood cells)
RDW (red blood cell distrib) reference range is 11.5 to 14.5%. If the value is above this, what is suggested?
Anisocytosis (variation in size)
note: may indicate the degree of poikilocytosis (variation in shape)
________ count is an indication of the responsiveness of the bone marrow to decreased RBCs.
Reticulocyte
Reticulocytes are immature RBC’s or some times called shift cells. They are larger than normal (7 μm) RBC’s
What are the small fragments of megakaryocytes that are released into the blood called? What do they aid in?
Platelets: they aid in clotting since they contain activators of coagulation
What is thrombocytosis? What is it due to? (7)
increased platelet count due to reactive conditions such as:
- infections
- iron def
- splenectomy
- hypothermia
- myeloproliferative disorders
- leukemia
- polycythemia vera
When is platelet count decreased? (6)
- Incr/decreased destruction
- pooling in spleen
- immunologic mechanisms
- drugs like heparin
- dilutional coagulopathies
- infection
- May raise the RDW
- Problem with cytoskeleton or hemoglobinization
- Extreme variation in shape and size
- May occur after a transfusion in a pt with microcytic anemia
Poikilocytosis
- Measure of variation in RBC size
- Just a marker that something’s wrong
- May occur after a transfusion in a pt with microcytic anemia
Anisocytosis
- Bizarrely-shaped red cells
- Spectrin mutation
- Autosomal recessive variant on hereditary spherocytosis
Hereditary pyropoikilocytosis
- These cells lack the central pallor, are small, round, and slightly darker in color
- Cytoskeleton may be defective or portions of the membrane may have been removed»_space; weak, less deformable membrane
Spherocytes
“Hereditary Spherocytosis”
RBC acanthocytes are a famous marker for what?
abetalipoproteinemia
- Coarse granulation resulting from aggregation of RNA
- A non-specific finding in anemia
- Classic example = lead poisoning
- Seen in Beta-thalassemias
RBC basophilic stippling
Lead inhibits the activity of what 2 enzymes involved in heme synthesis?
How are ringed sideroblasts formed?
Delta aminolevulinic acid and ferrochelatase.
Inhibiting ferrochelatase»_space; ringed sideroblasts
(iron remains within the mitochondria of the red cell precursors rather than joining the globin chains to make Hb molecules)
What are Howell-Jolly bodies?
If you see these, the pt may not have what organ?
What kind of anemia do you see Howell-Jolly bodies?
- Howell-Jolly bodies are fragments of nuclear material (DNA) in RBCs.
- Pt may not have a spleen, which typically removes them quickly.
- Hereditary spherocytosis (normocytic anemia with predominantly extravascular hemolysis)
In a blood smear, how could tell which cell is “polychromatophilic?”
It will be appear more purple because it hasn’t lost all of its purple-staining RNA.
- A spherocytosis variant
- Normal in camels, llamas, alpacas
Ovalocytes (elliptocytes)
Target cells. Think…
Hemoglobinopathy
Teardrop cells…
Something replacing the marrow.
Intracellular ring forms make the diagnosis of what?
Malaria
- Intra- AND extracellular rings helps to differentiate this protozoan from malaria.
- Use ticks as reservoir
Babesia
- Elongated and pale cells
- Seen in true iron deficiency anemia
Pencil cells
Iron-laden mitochondria seen in what?
The mitochondria are termed what?
Sideroblastic anemia
iron-laden mitochondria = Pappenheimer bodies
Paroxysmal cold hemoglobinuria causes what to happen between RBCs?
Agglutination
Rouleaux formation (coin-stacking of RBCs) is suggestive of what?
Plasma cell dyscrasia / myeloma / paraproteinemia
96% of a normal adult’s Hb is:
3% of a normal adult’s Hb is:
1% of a normal adult’s Hb is:
(96%) HbA = 2A + 2B
(3%) HbA2 = 2A + 2D
(1%) HbF = 2A + 2G
What are the 4 alpha chain shortages seen in alpha-thal?
1 gene deleted: asymptomatic
2 genes deleted: cis = worse, risk of severe thal in offspring, Asians … trans = Africans
3 genes deleted: 4B = HbH
4 genes deleted: 4G = Hb Bart’s
What is the sequence of RBC precursors? (5)
- Pronormoblast
- Basophilic normoblast (prorubricyte)
- Polychromatophilic normoblast (rubricyte)
- Orthochromatophilic normoblast (metarubricyte)
- Reticulocyte (“young reds”) – nucleus is exported before this step
How would you discriminate a pronormoblast from other RBC precursor cells in a blood smear?
Pronormoblast:
- Large, circular cell housing a large, circular nucleus
- Thin rim of cytoplasm around the nucleus
Describe how anemia presents clinically.
Anemia presents with signs and symptoms of hypoxia:
- Weakness, fatigue, malaise, dyspnea
- Pale conjunctiva and skin
- Headache and lightheadedness
- Angina, esp with preexisting CAD
What 3 things do you watch for when diagnosing hemolytic anemias?
- Reticulocytosis
- Incr indirect bilirubin
- Incr LDH
- Inherited defect of RBC cytoskeleton-membrane tethering proteins
- Membrane blebs are formed and lost over time – loss of membrane renders cells round (“spherocytes”) instead of disc-shaped … spherocytes are less able to maneuver through splenic sinusoids and are consumed by splenic macrophages»_space; anemia
Hereditary spherocytosis
- Spherocytes with loss of central pallor
- Incr RDW and incr MCHC (dark color)
- Splenomegaly, jaundice, and incr risk for bilirubin gallstones (extravascular hemolysis)
- Incr risk for aplastic crisis with parvovirus B19 infection of erythroid precursors
Hereditary spherocytosis
Hereditary spherocytosis is diagnosed with what test?
Osmotic fragility test – reveals increased spherocyte fragility in hypotonic solution
What are reticulocytes?
Young RBCs released from the bone marrow
-Identified on blood smear as larger cells with bluish cytoplasm (due to residual RNA)
What are Heinz bodies?
A deficiency in what enzyme will cause Heinz bodies to precipitate?
Denatured Hb that is often attached to the membrane
G6PD deficiency
How are Heinz bodies removed from RBCs?
What kind of cells result from their removal?
Heinz bodies are removed from RBCs by splenic macrophages, resulting in “bite cells.”
- X-linked recessive disorder resulting in reduced half-life of G6PD; renders cells susceptible to oxidative stress
- Oxidative stress (e.g., fava beans) precipitates Hb as Heinz bodies
- Presents with hemoglobinuria and back pain hours after exposure to oxidative stress
G6PD deficiency
- AR mutation in ß chain of Hb
- Normal glutamic acid (hydrophilic) is replaced with valine (hydrophobic)
- Gene carried by 10% of individuals of African descent (likely due to protective role against falciparum malaria)
- Arises when 2 abnormal ß genes are present»_space; >90% HbS in RBCs
Sickle cell disease
What happens to HbS when it gets deoxygenated?
What kind of cells does this result in?
- HbS polymerizes when deoxygenated
- HbS polymers aggregate into needle-like structures»_space; sickle cells
Which Hb prevents sickling?
HbF
-therefore children do not show symptoms for the first few months of life
What 3 things precipitate sickling?
Hypoxemia
Dehydration
Acidosis
- Leg ulcers
- Strokes
- Retinal infarcts
- Priapism
- Painful bone infarcts
- Thrombosis
- Pain management
Sickle cell disease
You see autosplenectomy in what disease?
Sickle cell disease
Acute chest syndrome (vaso-occlusion in pulmonary vasculature) is the MC cause of death in adult pts of what disease?
Sickle cell disease
Massive erythroid hyperplasia ensues from sickle cell dz, leading to what 3 things?
- Expansion of hematopoiesis into skull (‘crewcut’ appearance) and facial bones (‘chipmunk facies’)
- Extramedullary hematopoiesis with hepatomegaly
- Risk of aplastic crisis with parvovirus B19 infection of erythroid precursors
Explain sickle cell trait.
What does this result in?
One mutated and one normal ß chain; results in <50% HbS in RBCs, therefore these pts are generally asymptomatic
In sickle cell trait pts, sickling is caused by what 2 things?
- Hypoxia (high altitude)
- Damaged renal medulla (electrolyte loss)
- AR mutation in ß chain of Hb
- Normal glutamic acid is replaced by lysine at 6th AA position of ß chain
- Less common than sickle cell dz
- Presents with mild anemia due to extravascular hemolysis
- Characteristic HbC crystals (rod-shaped) are seen in RBCs on blood smear
- Mostly target cells in the blood
Hemoglobin C disease
- Result of the substitution of lysine for glutamic acid at the 26th amino acid of the ß globin chain (common in Asia)
- Presents with mild microcytosis and target cells are seen
Hemoglobin E
4 ß chains are seen in what dz?
HbH disease (alpha-thal when 3 genes are deleted)
- Lots of little tiny red cells (MCV = 65 fL)
- Mild anemia
- Pancake cells
- Maybe a few RBCs with basophilic stippling
Beta-thalassemia minor
- Normocytic, normochromic anemia with predominant intravascular hemolysis
- Acquired life-threatening dz characterized by complement-induced intravascular hemolytic anemia
- Occurs episodically, often at night during sleep when pH is lowest (activates complement)
- Main cause of death is thrombosis of the hepatic, portal, or cerebral veins
- Iron deficiency anemia may result from losing Hb into the urine
Paroxysmal nocturnal hemoglobinuria (PNH)
___ infection causes sickness and death largely (but not entirely) by damaging the immune system, leading to opportunistic Infections and unusual tumors / odd cell proliferations
HIV infection
____ produces consolidation of the lungs. The alveoli fill with micro-organisms with a limited or absent inflammatory response.
PCP
Look like crushed ping-pong
Produces no sputum !!!
PCP in combination with ______ in MSMs = first identification of AIDS. Linked to low CD4 counts (below 200)
Kaposi’s
A high-resolution CT scan of “PCP” shows what?
Ground-glass opacities because the alveoli are either packed or empty.
How do you dx PCP? Hint: what test?
Blood test! 1-3-beta-d-glucan component of pneumocystis wall
May have to induce sputum to send to lab (biopsy, aspirate, etc)
_________ may be complication of HIV infx. Rates are growing due to homeless population and transmission from HIV pts.
Tuberculosis
- A consumptive coagulopathy due to abnormal coagulation
- Poikilocytosis, schistocytes, decr platelets, microcytes
Disseminated intravascular coagulation (DIC)
- Cancer association: Hodgkin, non-Hodgkin, thymomas
- Systemic autoimmune dz – SLE, scleroderma, rheumatoid arthritis
- Viral infections in children
- Ulcerative colitis
- Benign ovarian tumors, such as dermoid cysts
Hemolytic anemias
AHA warm
- Cold agglutinins are due to IgM antibodies
- May be assoc with a lymphoproliferative disorder
- Can be 1) Idiopathic; 2) Secondary to infection, mycoplasma, mono, others; 3) Paroxysmal cold hemoglobinuria IgG against P blood groups
Hemolytic anemias
AHA cold
What is the test that detects whether Ig and/or complement is coating the surface of the pt’s RBCs?
What is a (+) test?
Direct antiglobulin test (“Direct Coombs” or DAT)
(+) test = agglutination of RBCs
What is the test that detects auto-antibodies or unexpected alloantibodies in pt’s plasma or serum?
What is a (+) test?
Indirect antiglobulin test (“Indirect Coombs”
(+) test = agglutination
- An acquired disorder of nuclear maturation
- High MCV, hypersegmented neutrophils, slight jaundice, high LDH
- Deficiency of B12, folate, or both, which is essential for DNA synthesis
- Pernicious anemia, inadequate intrinsic factor
- PS: variable degrees of cytopenias, often pancytopenia
- Hallmark feature = macrocytosis and oval macrocytes ***
- RBC fragments, schistocytes and inclusions, such as Howell-Jolly bodies, basophilic stippling and Cabot rings
Megaloblastic anemia
Bone marrow findings in megaloblastic anemia:
- Trilineage megaloblastic changes
- Nuclear-cytoplasmic dyssynchrony
- Erythroid hyperplasia
- Granulocytic hyperplasia
- A type of megaloblastic anemia in which the underlying cause is a defective intrinsic factor, which required for the absorption of vitamin B12
- Atrophic gastric parietal cells (supposed to make IF)
- Rare in children
Pernicious anemia
- Low serum iron
- High TIBC
- Low % saturation
- Low serum ferritin
- Absent bone marrow iron ***
- Microcytic, hypochromic and pencil cells
- Pts like to chew ice cubes
- Heavy periods, GI bleeding (hookworm), bad diet (junk food, vegans), malabsorption (famously sprue), achlorhydria
Iron deficiency anemia
27yo woman admitted with a hx of Crohn’s dz.
Labs: WBC 11.16, RBC 4.03, Hb 8.0, Hct 28.7, MCV 71.0, MCH 20.6, MCHC 28.6, RDW 17.2
Iron deficiency anemia
What is the test that detects whether Ig and/or complement is coating the surface of the pt’s RBCs?
What is a (+) test?
Direct antiglobulin test (“Direct Coombs”)
(+) test = agglutination of RBCs
- Normocytic, normochromic morphology early
- Microcytic, hypochromic morphology ***
- Hypo-regenerating, normocytic/normochromic morphology later on
- High ferritin
- Low TIBC *
- Low serum iron
- Low % saturation
- Interleukins acting on liver to produce hepcidin, which prevents marrow macrophages from releasing their iron to developing RBCs
- Causes today: osteomyelitis, TB, RA, leprosy, CF, bedsores
Anemia of chronic inflammation (disease)
- Selective decrease in bone marrow RBCs, without other associated cytopenias
- PS: chronic normocytic to slightly macrocytic anemia
- BM: normal cellular without erythroids
- Incr EPO levels
- Congenital causes, Diamond-Blackfan anemia
Pure red cell aplasia
- Occasionally produces infection of the cervical lymph nodes in healthy people, especially children.
- Can present as single-site lymphadenitis.
Mycobacterium avium organisms (like TB or other non-TB)
- A common childhood viral infection (“fifth disease,” “erythema infectiosum, “slapped face”)
- During illness, virus suppresses erythropoiesis
- Cause of aplastic crisis seen in ppl with chronic hemolysis (spherocytosis, sickle cell disease)
Parvo B19
How do we diagnose CMV?
- Rise in complement-fixing antibodies (4-fold titer over 2-4 weeks)
- Finding IgM 30% or more of IgG.
- Like the more common and more familiar Epstein-Barr infectious mononucleosis, CMV travels by kissing.
- A family of genetic illnesses with a severe lack of erythroid precursors in the marrow from birth
- Short stature, various craniofacial, thumb, and skeletal abnormalities
- Incr HbF, EPO levels, RBC adenosine deaminase levels
- RBC aplasia, decr reticulocyte count
- Macrocytic anemia (MCV = 110-140)
Diamond-Blackfan anemia
- In contrast to Diamond-Blackfan, these ppl have plenty of RBC precursors, but they do not develop properly
- Illness is characterized by megaloblastic changes in the BM along with ineffective erythropoiesis (dyserythropoiesis) due to lack of maturation as a result of mitotic defects
- Macrocytic anemia
- Anisopoikilocytosis, basophilic stippling, low reticulocyte count, and Cabot rings
- CDA II may mimic PNH due to incr hemolysis
Congenital dyserythropoietic anemia (CDA)
- Toxoplasmosis is infection with the protozoan Toxoplasma gondii, which completes its life cycle in ___.
- Avoid eating what?
cats (change the litter box!)
avoid eating undercooked meat!
- An acquired disorder of nuclear maturation
- Deficiency of B12, folate, or both, which is essential for DNA synthesis
- Pernicious anemia, inadequate intrinsic factor
- PS: variable degrees of cytopenias, often pancytopenia
- Hallmark feature = macrocytosis and oval macrocytes ***
- RBC fragments, schistocytes and inclusions, such as Howell-Jolly bodies, basophilic stippling and Cabot rings
Megaloblastic anemia
Causes of Mechanical Hemolysis (3)
- Old-fashioned heart valves
- Impact athletes (long-distance runners)
- Karate chopping and bongo drumming
- Pt who has Hb level above reference range and they’re not dehydrated
- May be secondary to chronic hypoxia, high-affinity Hb’s, or anabolic steroid use by bodybuilders
Polycythemia
CMV in the colon was a common problem in which pts?
AIDS pts
T/F: Involvement of the brain in CMV infections is rare, but is devastating.
TRUE
If cryptococcosis is suspected, perform what first?
Neuroimaging
also look at CSF
__________ ________ was well-known, in the old days, as a sign that HIV infection was progressing to the late stage (“AIDS”).
-Usually, the CD4 count will be below 100.
Esophageal candidiasis
Cryptosporidiosis is infection by C. hominis or C. parvum.
-Protozoans live in what area of the body? What does this contribute to in AIDS pts?
- Brush border of the small intestine
- Diarrhea in AIDS pts
- Toxoplasmosis is infection with the protozoan Toxoplasma gondii, which completes its life cycle in ___.
- Avoid eating what?
cats (change the litter box!)
avoid eating undercooked meat
How does toxoplasmosis present? How can we dx it?
-Primary infection is usually asymptomatic, or may mimic infectious mononucleosis
- Find anti-toxoplasmosis IgM without IgG in the serum
- Tachyzoites are found on fine-needle aspiration of the enlarged lymph nodes.
How does toxoplasmosis appear in the brain?
Ring-enhancing lesions (often in the basal ganglia)
Toxoplasmosis remains latent in the body after infection, and HIV patients who have antibodies as well as CD4 counts below ____ are prone to develop
100
Toxo is famous for involving the retina. What does it look like?
white fluff, less hemorrhage than CMV retinitis
- Decr serum iron
- Incr TIBC
- Decr % saturation
- Hypochromia and pencil cells
- Pts like to chew ice cubes
- Heavy periods, GI bleeding (hookworm), bad diet (junk food, vegans), malabsorption (famously sprue), achlorhydria
Iron deficiency anemia
27yo woman admitted with a hx of Crohn’s dz.
Labs: WBC 11.16, RBC 4.03, Hb 8.0, Hct 28.7, MCV 71.0, MCH 20.6, MCHC 28.6, RDW 17.2
Iron deficiency anemia
A single, narrow-based bud, and a capsule describes what?
Hint: Second most common cause of death in AIDS in Africa
Cryptococcus (C. neoformans)
Cryptococcus is related to which animal? Grows on which prep?
Pigeons!
India ink!
If cryptococcosis is suspected, perform what first?
Neuroimaging
also look at CSF
- An unusual bacterial infection due to immune compromise
- Solid masses of bugs
- Looks like bumps on skin
Bacillary angiomatosis
- Normocytic, normochromic morphology early
- Microcytic, hypochromic morphology
- Hypo-regenerating, normocytic/normochromic morphology later on
- Interleukins acting on liver to produce hepcidin, which prevents marrow macrophages from releasing their iron to developing RBCs
- Causes today: osteomyelitis, TB, RA, leprosy, CF, others
Anemia of chronic inflammation (disease)
- Selective decrease in bone marrow RBCs, without other associated cytopenias
- PS: chronic normocytic to slightly macrocytic anemia
- BM: normal cellular without erythroids
- Incr EPO levels
- Congenital causes, Diamond-Blackfan anemia
Pure red cell aplasia
Progressive multifocal leukoencephalopathy (PML) involves which virus? What does it damage?
- JC papovavirus
- Damages the brain
- CD4 count usually <200.
Cryptosporidiosis is infection by C. hominis or C. parvum. Protozoans live in what area of the body?
Brush border of the small intestine
diarrhea in AIDS
Today, the lab can test for cryptosporidium. Easiest is examining the _____ – cryptosporidia are acid-fast and can be easily seen on microscopy
stool
Does histoplasma capsulatum have a capsule?
NO!
Birds, bat droppings, starling roosts…think
histoplasmosis fungus
(2 micron yeasts) *
(It’s estimated that only about 1 in 2000 people who meet histoplasmosis in the wild will get seriously sick, but the risk is greater if there’s a big dose (camping in starling territory, cavers getting into bat guano)
Aspergillosis commonly follows which infection?
pneumocystis pneumonia
Fruiting body, 45 degree branching
Aspergillus
Spirochetosis of the colon seen in which infection?
Aspergillus
T/F: Zoster can occur at any CD4 count
True
- Erythroviruses (______ __): usually produce a mild flu-like illness that may be followed with a rash and/or joint pain (“fifth disease” / “erythema infectiosum”).
- Causes episodes of red cell production failure in folks with hemolytic anemias, or severe anemia before birth (“hydrops”)
parvo B19
- An unusual bacterial infection due to immune compromise
- Solid masses of bugs
- Looks like bumps on skin
Bacillary angiomatosis
Bartonella species
What are 6 acquired causes of pure red cell aplasia?
- Aplastic crisis
- Parvovirus B19
- Malnutrition
- Drugs (chloramphenicol is infamous)
- Thymoma or rarely other neoplasms
- Idiopathic
- A common childhood viral infection (“fifth disease,” “erythema infectiosum, “slapped face”)
- During illness, virus suppresses erythropoiesis
- Cause of aplastic crisis seen in ppl with chronic hemolysis (spherocytosis, sickle cell disease)
Parvo B19
- Due to defective DNA repair mechanism. Marrow stem cells are lost.
- Multiple congenital anomalies
- Trilineage, bone marrow failure, usually at an early age ***
- Substantial increased risk for other malignancies
Fanconi anemia
- A family of genetic illnesses with a severe lack of erythroid precursors in the marrow from birth
- Short stature, various craniofacial, thumb, and skeletal abnormalities
- Incr HbF, EPO levels, RBC adenosine deaminase levels
- RBC aplasia, decr reticulocyte count
- Macrocytic anemia (MCV = 110-140)
Diamond-Blackfan anemia
_______ is dry or flaky scalp/skin. Likely to flare up as CD4 counts drop below 400, and become severe below 200.
Seborrhea
