Term
| how does MM cause coagulopathy? |
|
Definition
| Fab portion of M protein binds to fibrinogen and inhibits its polymerization and clot formation. light chains can bind to factor X and cause factor X deficiency and bleeding. M protein can bind to platelets and interfere with their functions |
|
|
Term
| what is the triad of molecules shown to regulate osteoclast activity? |
|
Definition
| NF-kB (RANK), RANK-Ligand, osteoprotegrin |
|
|
Term
| describe how rank and rank-l work? what does opg do? |
|
Definition
| RANK is a receptor for RANK-L located on preosteoblasts and mature osteoclasts. Rank-ligand binding to RANK mediates the differentiation, function and survival of osteoclasts. OPG is a natural soluble decoy receptor of RANKL, it modulates the effect of RANKL and is able to prevent excessive bone resorption in the normal state. |
|
|
Term
| what causes bone disease in MM? |
|
Definition
| increased function of osteoclasts via INCREASED RANKL |
|
|
Term
| hypercalcemia in MM is caused by? clinical manifestations? |
|
Definition
| caused by increased bone resorption. --> muscle weakness from abn nerve conduction, nausea, vomiting, poyura, polydypsia, dehydration, induced renal dysfunction |
|
|
Term
| what are the causes of death in MM (usually)? |
|
Definition
|
|
Term
| what is staging in MM based on? and what are the stages? |
|
Definition
| staging based on amt of beta2 microglobulin found in the serum. stage I (<3.5, 62 mp survival); stage 2 (between 3.5 and 5, survival 44 mos); stage 3 (>5, survival 29 mos) |
|
|
Term
| current gold standard for primary therapy in MM? |
|
Definition
| thalidomide, revlimid or bortezomib combined with dexamethasone with bisphosphonates. (high dose chemo with stem cell transplant indicated for appropriate patients) |
|
|
Term
| CD surface markers for myeloblasts? |
|
Definition
|
|
Term
| CD surface markers for monoblasts? |
|
Definition
|
|
Term
| what are auer rods made up of? and what are they pathognomonic for? |
|
Definition
| made up for lysosomes and granules fused in a row. pathognomonic for myeloid lineage cell |
|
|
Term
| which AML puts patient at risk for DIC? |
|
Definition
| acute promyelocytic leukemia t(15;17). degranulation of promyelocytes. |
|
|
Term
| AML with MDS related changes, what cytogenic abnormalities are common? |
|
Definition
|
|
Term
| what 2 drugs put us at risk for therapy-related AML? |
|
Definition
| 1. alkylating agents (5-10 yrs after tx) pts usually have preceding MDS from previous therapy 2. topoisomerase II inhibitors (1-3 yrs after tx) involves disruption of MLL gene, poor prognosis |
|
|
Term
| which AMLs put us at risk for stroke? |
|
Definition
| MLL (pure monocytic lineage), AML M5 (acute monoblastic leukemia) |
|
|
Term
| which AML are unresponsive to therapy? |
|
Definition
| AML following MDS or therapy related |
|
|
Term
| what are the global treatments for AML? |
|
Definition
| cytarabine and daunorubicin with allopurinol/hydration to protect kidneys from uric acid precipitation (can use cytarabine alone) |
|
|
Term
| what is normal serum ferritin levels? |
|
Definition
|
|
Term
| what iron parameters are diagnostic for iron deficiency? |
|
Definition
| <10ng/mL ferritin. <10% transferrin saturation. increased total transferrin level (total iron binding capacity) |
|
|
Term
| how to distinguish IDA from ACD? |
|
Definition
| IDA has elevated transferrin and ACD has decreased transferrin |
|
|
Term
|
Definition
|
|
Term
|
Definition
| excessive absorption of food iron (6-8 mg/day vs 1-2) --> heart, liver, pancreas, kidney, joint disease |
|
|
Term
| what is the most common cause of hemochromatosis? |
|
Definition
| autosomal recessive homozygous mutation C282Y in HFE gene --> decreased expression of hepcidin --> increased export of iron from duodenal epithelium (penetrance of mutation less than 30% in males and less than 10% in females). heterozygotes also at risk, carrier state common and provides advantage d/t increased absorption of fod iron preventing nutritional deficiency. |
|
|
Term
| what lab results are consistent with hemochromatosis? |
|
Definition
| serum transferrin >45%, serum ferritin > 1000 ng/mL (indicates tx by phlebotomy until ferritin <50) |
|
|
Term
| what 3 things increase our absorption of iron? |
|
Definition
| recent blood loss, genetic disorders (hemochromatosis), thalassemias |
|
|
Term
| increased serum ferritin indicates? |
|
Definition
| chronic inflammatory disease or secondary to hemochromatosis |
|
|
Term
| whats the difference between hemochromatosis and hemosiderosis? |
|
Definition
| hemochromatosis is a genetic disorder. hemosiderosis is d/t frequent transfusions, increased dietary iron absorption in chronic hemolytic states) |
|
|
Term
| what would we find on a physical exam of a patient with iron deficiency anemia? |
|
Definition
| conjunctival pallor, nail bed changes (koilonychia), positive stool guiac, esophageal web, cheilosis |
|
|
Term
| what are the causes of ACD? |
|
Definition
| cancer, chronic infection, collagen-vascular disorders |
|
|
Term
| in iron deficient states, what happens to the level of ferritin? |
|
Definition
| decreased. body stores of iron low --> cytosolic aconitase conformational change --> binds to iron response element located at the 5' end of the ferritin mRNA --> inhibits translation of the ferritin mRNA |
|
|
Term
| when body is iron deficient, what happens to transferrin levels? |
|
Definition
| increases. there's an iron response element on the 3' end of transferrin mRNA (cf 5' end of ferritin mRNA) --> iron low? --> aconitase binds to the IRE and stabilizes the mRNA (cf aconitase INHIBITS ferritin mRNA) |
|
|
Term
| how do we distinguish between IDA and thalassemias which both have decreased MCH and MCV? |
|
Definition
| in thalassemias, all cells affected equally --> normal RDW (vs. IDA has increased RDW); iron absorption may be increased (>50 ng/mL); RED BLOOD CELL CT NORMAL (normal RBC ct r/o IDA) |
|
|
Term
| how do we diagnose B-thalassemia? |
|
Definition
| hemoglobin electrophoresis demonstrating elevation of HbA2 |
|
|
Term
| how do we diagnose a-Thalassemia? |
|
Definition
| southern blot of alpha globin gene domain (detects deletions of one or both of the 2 alpha globin genes located on one or both chromosome 16s) |
|
|
Term
| why does the transferrin level not increase in ACD? |
|
Definition
| no increase in erythroid compartment mass (they produce it), and no change in the activity of the iron-binding protein |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| alpha2Agamma2, alpha2Ggamma2 |
|
|
Term
| how do we get abnormal hemoglobin in hemoglobin S? |
|
Definition
| GAG --> GTG mutation in codon 6 of the beta globin gene (valine in place of glutamic acid) --> alpha2beta2S |
|
|
Term
| what is the blood make-up of people with sickle cell anemia? |
|
Definition
| 85-95% HbS and 3-20% HbF (F cells - protective. higher proportion of F cell means more interference with sickling, but protective effect can never be complete bc only a minor proportion of circulating erythrocytes have the HbF), normal complement of HbA2 but can make no HbA |
|
|
Term
| sickle cell anemia: evaluate blood parameters: hematocrit, retic, serum indirect bilirubin, LDH |
|
Definition
| hematocrit 18-28%; retic increased 5-10%; indirect bilirubin increased, LDH elevated |
|
|
Term
| what is a serious complication of anemia? |
|
Definition
| acute chest syndrome - subjects develop severe shortness of breath, oxygen desaturation, lung infiltrates, chest pain and fever. (confused with pneumonia, pulm infarc, etc.) may be fatal |
|
|
Term
| why do we have to monitor fluid administration to sickle cell anemia patients? |
|
Definition
| their kidneys cannot concentrate urine and conserve water appropriately (hyposthenuria) --> tendency to dehydrate or become volume overloaded easily |
|
|
Term
| which drug has been shown to decrease the frequency of painful crises and other complications? |
|
Definition
|
|
Term
| what therapy do we use for sickle cell anemic children who experience stroke? |
|
Definition
| chronic exchange transfusion (lower proportion of HbS in circulation below 30%) |
|
|
Term
| what genetic abnormality leads to the formation of HbC? |
|
Definition
| GAG --> AAG mutation in the 6th codon of B globin gene, causing lysine in place of valine |
|
|
Term
| describe hemoglobin C disease (homozygous HbC) |
|
Definition
| mild, chronic hemolytic anemia, hematocrit ~30%.frequent target cells and spherocytes. HbC has tendency to form crystals within RBC subjecting the cells to phagocytosis by macrophages in the spleen. exhibit splenomegaly. have 98% HbC and NO HbA. generally well |
|
|
Term
| describe hemoglobin C trait. |
|
Definition
| subjects not ill, have half HbA and half HbC. not anemic. peripheral blood still has significant amount of target cells and spherocytes. |
|
|
Term
| describe the clinical manifestations of hemoglobin SC disease. |
|
Definition
| closely resembles sickle cell anemia - painful crises, thrombotic and vasculooclusive events, renal disease, retinal disease, acute chest syndrome. have hct slightly higher than sickle cell anemia, peripheral blood shows sickle cells, target cells and spherocytes. presence of SPLENOMEGALY r/o sickle cell anemia. |
|
|
Term
| what genetic change causes HbE? |
|
Definition
| substitution of lysine for glutamic acid at position 26 of beta globin gene. |
|
|
Term
| what genetic change causes HbE? |
|
Definition
| substitution of lysine for glutamic acid at position 26 of beta globin gene --> establishes an abnormal potential mRNA splice site --> proportion of mutant mRNA molecules undergo incorrect splicing (therefore not 50% HbA and 50% HbE, 75% HbA and 25% HbE) |
|
|
Term
| do people with unstable hemoglobins (d/t mutations that destabilize either binding of heme to globin or destabilizing the entire molecule) exhibit symptoms? |
|
Definition
| yes, but not all the time, only when triggered by exposure to a variety of drugs with redox properties (anti-malarials, sulfa drugs) or when they develop high fevers. then --> acute hemolytic episodes with sudden development of severe anemia, jaundice, dark urine. (otherwise exhibit mild, chronic hemolysis with little or no anemia) |
|
|
Term
| what happens to the oxy-hemoglobin dissociation curve, the hematocrit, and the EPO secretion of people with Hb with increased affinity for oxygen? |
|
Definition
| dissociation curve = left shifted with a decreased p50. tissue hypoxia --> increased EPO secretion --> markedly elevated Hct (hemoglobins inherited co-dominantly, therefore families have congenital erythrocytosis) |
|
|
Term
| what are the abnormal clinical findings of beta thalassemia trait? |
|
Definition
| normal healthy life. microcytosis, hypochromia, slightly enlarged spleen d/t chronic red cell sequestration, ELEVATED HbA2 (characteristic) |
|
|
Term
| what are the major clinical features of beta-thalassemia major? (pathophys) |
|
Definition
| unpaired excess alpha globin chains unstable and precipitate in cytoplasm --> precipitates bind to inside of RBC membrane --> damage and mark for destruction by macs --> destruction in marrow (intramedullary hemolysis) and periphery (hemolysis) --> severe life-long anemia requiring regular transfusion therapy |
|
|
Term
| what happens to untransfued children with beta-thalassemia major? |
|
Definition
developmental abnormalities. massive overgrowth of erythropoietic tissue in bone marrow --> thinning of bone cortices --> skeletal abnormalities, distorted facial structure, pathological fractures.
extramedullary hematopoiesis --> massive splenomegaly, hepatomegaly, tumor-like masses of erythroid tissue in thorax, spinal canal, --> spinal cord compression |
|
|
Term
| if a patient has one sickle beta globin gene and one gene for beta thalassemia and the gene is beta +, what is the ratio of HbS to HbA? |
|
Definition
| always will make more HbS than HbA (vs. sickle cell anemia where there is always more HbA vs HbS) |
|
|
Term
| if patient has sickle cell gene AND beta thalassemia gene, beta 0, what is the HbS to HbA ratio? |
|
Definition
| makes ONLY HbS and no HbA. |
|
|
Term
| what clinical features are present in sickle cell - beta - thalassemia ? |
|
Definition
| splenomegaly, elevated HbA2, microcytosis |
|
|
Term
| what is the hydrops fetalis oxy-hemoglobian dissociation curve look like? |
|
Definition
| left shifted and hyperbolic rather than sigmoidal in shape. |
|
|
Term
| what are the clinical features of alpha thalassemia trait? |
|
Definition
| (2-3 alpha globin chains, and 1-2 deleted) --> hypochromia, microcytosis, elevated RBC counts, no anemia |
|
|
Term
| clinical features of HbH disease? |
|
Definition
| (subjects have only ONE alpha globin gene, and 3 deleted) --> hemolytic anemia of varying severity, more severe hypochromia and microcytosis than alpha thalassemia trait, splenomegaly, HbH (5-10%) |
|
|
Term
| clinical features of hydrops fetalis? |
|
Definition
| can make no alpha globin and hence NO HbF or HbA --> only have gamma4 tetramers (Hb Bart's) --> severe anemia, tissue hypoxia, CHF in utero, edematous, still born or die shortly after death |
|
|
Term
| what are some things that might cause MDS? |
|
Definition
| benzene (alkylating agents), topoisomerase inhibitors, radiation, DNA damage, decreased DNA repair, loss of chromosomal integrity, after hematological malignancies |
|
|
Term
| what's considered good cytogentics in MDS? |
|
Definition
|
|
Term
| what's poor cytogenetics in MDS? |
|
Definition
|
|
Term
| what's usually the first treatment choice for MDS? |
|
Definition
| growth factors (EPO, g-csf) |
|
|
Term
| when is g-csf used as tx in mds? |
|
Definition
| when the patient has an infection (to boost neutrophil counts) does not improve survival, does not help with prophylaxis, can be used in combination with EPO. |
|
|
Term
| when do we usually want to start iron chelation therapy? |
|
Definition
| after 20-30 units given, to decrease iron overload. |
|
|
Term
| what are 2 examples of hypomethylating agents used to treat mds? |
|
Definition
| azacitidine and decitabine (delays time to leukemic transformation, improves overall survival, high response rate) |
|
|
Term
|
Definition
| drug used in 5q- MDS or low-risk MDS without 5q-. can cause cytogenic remission (chr abn disappears). is an immune modulatory, anti-angiogenic drug that acts on the BM stroma. high response rate. transfusion independence. no neuropathy |
|
|
Term
| what is the only curative therapy for MDS? |
|
Definition
| allogenic stem cell transplantation. high treatment related morbidity and mortality. need donor HLA matched, best used in the young. |
|
|
Term
|
Definition
| (subgroup of MDS) prolonged course, not very aggressive, <25% transformation to MDS, anemia is prominent. MONONUCLEAR MICROMEGAKARYOCYTES = pathognomonic. transfusion dependent --> iron overload. responsive to lenalidomide! |
|
|
Term
| what do we use to treat hypoplastic MDS? |
|
Definition
| anti-thymocyte globulin and cyclosporine. high dose steroids/prednisone |
|
|
Term
|
Definition
| overlap syndrome (MDS and MPD) uncommon. shows trilineage dysplasia, monocytosis, anemia, hepatomegaly, splenomegaly, granulomonocytic hyperplasia, PDGFR-beta translocations (good response to imanitib) tx with chemotherapy |
|
|
Term
| what is fanconi's anemia? |
|
Definition
| inherited aplastic anemia (autosomal recessive) short stature, cafe au lait spots, anomalies of thumb/radius, renal anomalies, progressive pancytopenia, increased risk of malignancy |
|
|
Term
| most common causes of secondary aplastic anemia? |
|
Definition
| EB, hepatitis, radiation, chemo, benzene, drug rxn, pregnancy, immune |
|
|
Term
| what is the treatment for aplastic anemia? |
|
Definition
| <45 --> BMT. >45 --> immunosuppression therapy (antithymocyte globulin, antilymphocyte globulin, cyclosporin, cyclophosphamide, methylprednisone) |
|
|
Term
|
Definition
|
|
Term
| typical natural history of CML? (timeline) |
|
Definition
| chronic phase 25 months, accelerated phase 12 months, blast crisis 1 month (blast crisis generally refractory to therapy) |
|
|
Term
| what is the etiology of CML? |
|
Definition
| association with ionizing radiation and radiation therapy |
|
|
Term
| how long does it take BM to fill up with Ph+ chromosomes fom the time the first Ph+ chromosome is obvious to clinical disesae? |
|
Definition
|
|
Term
| malignant transformation in CML occurs in which cell? |
|
Definition
| pluripotential stem cell bc Ph+ found in all cell lineages |
|
|
Term
| CML - hematologic remission means |
|
Definition
| normal blood count and normal bone marrow |
|
|
Term
| cytogenic remission means |
|
Definition
|
|
Term
| CML molecular remission means? |
|
Definition
|
|
Term
| what therapies are used to treat CML? |
|
Definition
| allogenic stem cell transplantation (major curative modality, used in young w/no other comorbidities and HLA match), alpha-interferon (alternative to those who cant have transplant, can induce cytogenic responses, can induce hematologic remissions, cytogenic responses) hydroxyurea, gleevac |
|
|
Term
|
Definition
| occupies the ATP binding site in bcr-abl oncoprotein, prevents transfer of phosphate groups to tyrosine kinase residues on substrate molecules involved in signal transduction |
|
|
Term
| what is the malignant cell of origin in PV? |
|
Definition
|
|
Term
| describe PV progenitors' response to cytokines |
|
Definition
| hypersensitive to cytokines (EPO, TPO, GM-CSF, SCF) |
|
|
Term
| what is the etiology of PV? |
|
Definition
| aberrant intracellular signaling (single, acquired somatic point mutation in tyrosine kinasse JAK2) V617F mutation. all the receptors for growth factors that PV progenitors are hypersensitive to signal thru JAK2 |
|
|
Term
| symptoms of PV all relate back to these 3 problems |
|
Definition
| hyperviscosity, elevated histamine release (d/t increase in basophils), microvascular events. (sx: headache, pruritis, weakness, dyspnea, dizzziness, visual changes, weight loss, epigastric pain, sweating, painful paresthesias of hands and feet) |
|
|
Term
| how do we differentiate between relative polycythemia and absolute polycythemia? |
|
Definition
| relative would have normal red cell mass and decreased plasma volume; absolute polycythemia would have increased red cell mass and normal plas a volume |
|
|
Term
| how do we differentiate between secondary polycythemia and polycythemia vera? |
|
Definition
| secondary would have increased (or normal) EPO; PV would have decreased (or normal) EPO |
|
|
Term
| what is the etiology of essential thrombocythemia? |
|
Definition
| mutation of JAK2 (V617F) in 50% patients. mutations in c-MPL (receptor for TPO) in small percentage of pts |
|
|
Term
| what is responsible for the thrombophilia in ET? |
|
Definition
| NOT increased platelet count alone. some suggestion that elevated WBC ct may contribute. |
|
|
Term
| what causes uncontrolled thrombocytosis and clinical bleeding in ET patients/ |
|
Definition
| removal of high molecular weight VWF multimers from circulation by the excessive number of platelets |
|
|
Term
| what is the treatment for ET? |
|
Definition
| hydroxyurea, also management of reversible CV risk factors (smoking, obesity, etc) and all patients, regardless of risk should receive low dose aspirin unless contraindicated |
|
|
Term
| what causes fibrosis of the bone marrow in primary myelofibrosis? |
|
Definition
| increased collagen and/or reticulin deposition. normal bone marrow fibroblasts are stimulated to produce collagen/reticulin by growth factors that are released by megakaryocytes (PDGF, TGF-beta, FGF, etc.) |
|
|
Term
| tx for primary myelofibrosis? |
|
Definition
| mainly supportive (blood transfusions and EPO for anemia; hydroxyurea and radiation for splenomegaly; splenectomy in select pts; allogenic stem cell transplantation) |
|
|
Term
| which HLA types are important in graft failure? |
|
Definition
|
|
Term
| GVHD is a greater risk in which class of disparities? |
|
Definition
| class II (HLA DR, DQ, DP) |
|
|
Term
| which type of stem cell carries the lowest risk for GVHD? |
|
Definition
|
|
Term
| acute GVHD involves what clinical manifestations? |
|
Definition
| skin, GI tract and liver (up to 100 days after raft) |
|
|
Term
| chronic GVHD involves what clinical manifestations? |
|
Definition
| chronic inflammation, appears like an autoimmune disorder |
|
|
Term
| whats the difference b/w GVHD and GVL? |
|
Definition
| GVHD T cells respond to broadly expressed host antigens; GVL T cells respond to hematopoietically restricted host antigens |
|
|
Term
| how long does it take infected hepatocytes to rupture after initial infection with sporozoite? |
|
Definition
| 8-15 days (releases merozoites) |
|
|
Term
| how do merozoites gain entry into RBC? |
|
Definition
| specific receptors on RBC (Duffy blood group glycoprotein for P. vivax and glycophorin A & C and band 3 protein for falciparum) --> parasite-induced phagocytosis |
|
|
Term
| which form of RBC does p. vivax infect? |
|
Definition
|
|
Term
| which RBC form does p. ovale infect? |
|
Definition
|
|
Term
| which RBC form does p. malariae infect? |
|
Definition
|
|
Term
| which RBC form does falciparum infect? |
|
Definition
|
|
Term
| what happens after merozoites get into RBC? |
|
Definition
| they de-differentiate into trophozoites --> divide (called shizonts - dividing form) --> generation of merozoites that infect other RBC (some trophozoites develop into gametocytes) |
|
|
Term
| what is the life span of an adult anopheline mosquito? |
|
Definition
|
|
Term
| how long does it take falciparum to develop in a mosquito? |
|
Definition
|
|
Term
| what is a prepatent period and how long does it last? |
|
Definition
| period between infection and detection of parasites (5-14 days) |
|
|
Term
| what is an incubation period and how long does it last in malaria? |
|
Definition
| period between infection and appearance of clinical sx; 1 week to 1 month |
|
|
Term
| what symptoms characterize the paroxysm phase of malaria? |
|
Definition
| shaking chills --> high fever --> intense sweating/exhaustion --> feel better until next paroxysm |
|
|
Term
| which spp. have 48 hour paroxysms? 72? continuous? |
|
Definition
| p.vivax, p.falciparum, p.ovale have 48 hour. p.malariae has 72 hr.; synchrony of merozoite release is less marked in falciparum, so fever may be more or less continuous |
|
|
Term
| recrudescence may occur in all four spp but for how long after initial infection? |
|
Definition
| in p.falciparum 1-3 years after primary infection; in p.malariae 25-30 years after primary infection; can occur in ovale and vivax but cannot be distinguished from a relapse |
|
|
Term
| what's causing the fever in malaria paroxysms? |
|
Definition
| massive amount of antigen being released at once (each progeny released is antigenically different) and release of endogenous pyrogens (TNFa and IL1, IL6) |
|
|
Term
| what causes anemia in malarial infections? |
|
Definition
| hemolysis of the infected RBC, abnormally rapid splenic removal of non-parasitized rbc and dyserythropoiesis |
|
|
Term
| what causes cerebral malaria? |
|
Definition
| attachment of both infected and uninfected rbc to vascular endothelium (cytoadherence) --> impaired microcirulation --> tissue hypoxia (hypoperfusion of brain) and hypoglycemia --> in kids may present as seizures or coma and in adults altered mental status |
|
|
Term
| what mediates cytoadherence in malaria? (adherence of RBC to endothelial vessels causing CNS effects) |
|
Definition
| each spp. has characteristic morphological changes in the infected erythrocyte membrane. (falciparum produces proteins that form knob-like protrusions) i.e. pfEMP1 binds to CD36 and ICAM-1 and thrombospondin on the vascular endothelium. also when infected RBC rupture, they release TNFa, IL1, IL6, INFg that cause fever and also do something to the endothelial wall to make them better at binding infected rbc (upregulate cd36, icam1?) |
|
|
Term
| what causes glomerulonephritis in malaria? |
|
Definition
| immune complex deposition from p.malariae infection |
|
|
Term
| what causes pulmonary edema in malaria infections? |
|
Definition
| leaky capillaries (mediated by elevated TNFa levels?) |
|
|
Term
| what causes watery diarrhea in malaria? |
|
Definition
| cytoadherence of parasitized rbc in microvasculature of both the small and large intestines |
|
|
Term
| what happens if there's a p.vivax infection and a p.vivax merozoite comes into contact with a duffy-negative rbc? |
|
Definition
| merozoite attachment can still occur, but junction formation does not proceed |
|
|
Term
| how does band3 help falciparum gain entry into rbc? |
|
Definition
| attachment of merozoites to band3 induces rearrangment of intramembrane particles and formation of a junction between merozoite and rbc membranes --> junction expands and internalizes and encloses completely |
|
|
Term
| why does sickle cell heterozygosity confer resistance to malaria? |
|
Definition
| intracellular K+ decreases in HbS/A erythrocytes under low O2 tension and that causes parasite death. sickling may also render rbc more vulnerable to phagocytosis |
|
|
Term
| is immunity against malaria permanent? |
|
Definition
| no. requires continued exposure. susceptibility returns if a person removed from endemic area returns. |
|
|
Term
| what is the gold standard of diagnosis for malaria? |
|
Definition
| microscopy (thin or thick smears --> soak in distilled h20 --> rbc lyse --> parasites remain sticking together) see more parasites in thick smear, species differentiation easier in thin smear. |
|
|
Term
| if a person is glycophorin A, B or C deficient, which form of malaria are they resistant to? |
|
Definition
|
|
Term
| if a person lacks band 3 protein, what are they resistant to? |
|
Definition
|
|
