Disorders of RBCs DSA Flashcards
iron def anemia- essentials of dx
- serum ferritin < 12 or < 30 if also anemic
- caused by bleeding unless proved otherwise
- responds to iron therapy
iron def anemia- signs and sx’s
- anemia
- smooth tongue, brittle nails, spooning of nails, cheilosis
- esophageal webs (plummer-vinson syndrome)
- pica
iron def anemia- lab
- anemia with MCV (initially)
- anemia with low MCV
- ferritin < 12- indicates depletion of iron stores
other causes of microcytic anemia
- chronic dz
- thalassemia
- lead poisoning
- X-linked sideroblastic anemia
Anemia of chronic dz- essentials of dx
- mild/moderate normocytic or microcytic anemia
- normal or inc ferritin and normal or reduced transferrin
- underlying chronic dz
Anemia of chronic dz- types
- anemia of infl- hepcidin inc- iron-restricted erythropoiesis
- anemia of organ failure- erythropoietin is reduced
- anemia of the elderly- resistance to RBC prod in response to erythropoietin, dec in erythropoietin prod (dec nephron mass), chronic infl cytokines cause deg in erythropoietin
Anemia of chronic dz- tx
- tx the cause
- if severe anemia (Hg < 10)- RBC transfusions or parenteral recombinant erythropoietin
Thalassemias- essentials of dx
- microcytosis
- FH
- lifelong personal hx of microcytic anemia
- normal or elevated RBC count
- abnormal RBC morphology with microcytes, hypochromia, acanthocytes, target cells
- B-thalassemia- elevated levels of hemoglobin A2 or F
Thalassemias- described as
- trait- lab features w/o clinical impact
- intermedia- occasional RDC transfusion requirement or other clinical impact
- major- life-threatening, transfusion-dep
Alpha-Thalassemia syndromes
- due to gene deletions
- asia, china
- silent carrier- 3 alpha genes
- Thalassemia minor (trait)- 2 alpha genes
- Hemoglobin H dz- 1 alpha gene
- Hydrops fetalis- 0 alpha genes
B-Thalassemia syndromes
- due to point mutations
- mediterranean pts
- T minor- Bo, B+ (elevated HbA2)
- T intermedia- B+ (mild)
- T major- Bo
- T major- B+
B-Thalassemia major- sx
- at 6-9 months- anemia requiring transfusions
- stunted growth, bony deformities
- transfusional iron overload- HF, cardiac arrhythmias, cirrhosis
Vit B12 def- essentials of dx
- macrocytic anemia
- megaloblastic blood smear (macro-ovalocytes and hypersegmented neutrophils)
- low serum vit B12 level
Vit B12 def- sx
- anemia
- glossitis
- peripheral n’s- paresthesias first, then balance or proprioception impairment
folic acid def- essentials of dx
- macrocytic anemia
- megaloblastic blood smear (macro-ovalocytes and hypersegmented neutrophils)
- reduced folic acid levels in RBCs or serum
- normal serum VitB12 level
lab features that suggest hemolysis
- haptoglobin decreased (normally binds/clears hemoglobin)
- inc of indirect bilirubin
Paroxysmal Nocturnal Hemoglobinuria- essentials of dx
- episodic hemoglobinuria
- thrombosis is common
- suspect in confusing cases of hemolytic anemia or pancytopenia
- flow cytometry demonstrates deficiencies of CD55 and CD59
- lysis of RBCs by complement
Paroxysmal Nocturnal Hemoglobinuria- sx, signs
- reddish-brown urine
- prone to thrombosis- mesenteric, hepatic v’s, CNS veins, skin vessels
Paroxysmal Nocturnal Hemoglobinuria- lab
- serum LD elevated
- flow cytometry- CD55 and 59
- FLAER assay- sensitive
Paroxysmal Nocturnal Hemoglobinuria- tx
- most pts have mild dz that doesnt require intervention
- if severe- allogeneic HSC transplantation
- Eculizumab (ab against complement protein C5)
Glucose-6-P Dehydrogenase Deficiency- essentials of dx
- X-linked recessive disorder (common in American black men)
- episodic hemolysis in response to oxidant drugs or infection
- Heinz bodies, bite cells and blister cells on PBS
- reduced levels of G6PD b/w hemolytic episodes
Glucose-6-P Dehydrogenase Deficiency- tx
-avoid oxidant drugs!!
Sickle Cell Anemia- essentials of dx
- recurrent pain episodes
- FH and lifelong hx of hemolytic anemia
- irreversibly sickled cells on PBS
- Hemoglobin S is the major hemoglobin seen on electrophoresis
Sickle Cell Anemia- signs, sx
- chronic hemolytic anemia- jaundice, pigment gallstones, splenomegaly
- vaso-occlusion crises- bones, chest
Sickle Cell Anemia- lab dx
-hemoglobin electrophoresis- Hemoglobin S 85-98% of hemoglobin
Sickle Cell Anemia- tx
- hydroxyurea- reduces freq of pain crises
- supportive care- mainstay!- folic acid supplementation
- vaso-occlusive crises- exchange transfusions
Autoimmune Hemolytic Anemia- essentials of dx
- acquired hemolytic anemia caused by IgG autoab
- spherocytes and reticulocytosis on PBS
- positive antiglobulin (coombs) test
Autoimmune Hemolytic Anemia- caused by?
- idiopathic (50%)
- in assoc with SLE, CLL, or lymphoma
Autoimmune Hemolytic Anemia- tx
- prednisone
- if ineffective- splenectomy
- rituximab
Cold Agglutinin Disease- essentials of dx
- inc reticulocytes on PBS
- antiglobulin (coombs) test positive only for complement
- positive cold agglutinin titer
Cold Agglutinin Disease- caused by?
-IgM autoab against an antigen on RBCs at lower temps- fixes complement- causes extravascular hemolysis
Cold Agglutinin Disease- tx
-Rituximab
Aplastic Anemia- essentials of dx
- pancytopenia
- no abnormal hematopoietic cells seen in blood or BM
- hypocellular BM
Aplastic Anemia- caused by?
- autoimmune- idiopathic (most common), SLE
- congenital- defects in telomere length maintenance
- chemotherapy
- toxins
- drugs
- pregnancy
- PNH
Aplastic Anemia- tx
- mild- erythropoietic or myeloid GFs, RBC and plt transfusions
- severe (neutrophil count <500, plts < 20,000, reticulocytes <1%, BM cellularity < 20%)- allogeneic BM transplantation (HLA-matched sibling)
- adults > 40 without donor- immunosuppression with ATG (equine antithymocyte globulin) plus cyclosporine
Acute intermittent porphyria- essentials of dx
- unexplained abd crisis, generally in young women
- acute peripheral or CNS dysfxn; recurrent psychiatric illnesses
- hyponatremia
- porphobilinogen in the urine during an attack
Acute intermittent porphyria- types
- presents in adulthood as AIP- inherited AD- mutation in HMBS
- partial def of hydroxymethylbilane synthase activity- inc excretion of aminolevulinic acid and porphobilinogen in urine
- characteristic abd pain- due to abnormalities in autonomic innervatoin in hte gut
Acute intermittent porphyria- signs, sx
- intermittent abd pain- neurologic!
- peripheral neuropathy- can be mild or profound
- CNS manifestations- seziures, altered consciousness, psychosi
Acute intermittent porphyria- lab
- hyponatremia
- inc amt of porphobilinogen in urine during an acute attck
- mutations in HMBS causing AIP- in 90% of pts
Acute intermittent porphyria- prevention
Acute intermittent porphyria- prevention
Acute intermittent porphyria- tx
- high-carb diet
- acute attacks- tx with analgesics, IV glucose in saline and hematin
Porphyria cutanea tarda- essentials of dx
- noninfl blisters on sun-exposed sites, esp the dorsal surfaces of the hands
- hypertrichosis, skin fragility
- assoc liver dz
- elevated urine porphyrins
Porphyria cutanea tarda- what is it?
- most common type of porphyria!
- assoc with ingestion of certain meds (estrogens) and liver dz from alcoholism, hemochromatosis or hep C
Porphyria cutanea tarda- sx, signs
- painless blistering and fragility of skin on hands
- facial hypertrichosis and hyperpigmentation is common
Porphyria cutanea tarda- lab
-urinary uroporphyrins- elevated 2x-5x bove coproporphyrins
Porphyria cutanea tarda- prevention
-barrier sun protection
Porphyria cutanea tarda- tx
- stop triggering medications
- reduce alcohol consumption
- most pts improve with treatment
- phlebotomy without oral iron supplementation; can be with low-dose antimalarial medication
