Mini 3 - Heme/Lymph/Musk 2 Flashcards
What is the structure of heme?
One Fe2+ in the center, protoporphyrin IX (tetrapyrrole ring).
Where is heme synthesized? Is it mostly excreted or recycled?
Mostly in BM, some in liver (for cyt P450), other minor locations.
Mostly excreted.
What is the rate limiting step of heme synthesis?
Porphyrin synthesis - delta-aminolevulinate synthetase (ALAS1 (liver)/ALAS2 (BM)) combine glycine and succinyl CoA to make ALA.
What controls ALAS1 and ALAS2 expression?
Hemin and low iron decrease ALAS1 and ALAS2 expression respectively.
ALAS2 also regulated by EPO.
What is X-linked sideroblastic anemia?
ALAS2 deficiency. Ringed sideroblasts, nucleated erythroblasts with mitochondrial iron granules.
Describe heme synthesis after ALAS.
In the cytosol, 2 ALAs are condensed to porphobilogen with ALA dehydrogenase.
Then condensation to hydroxymethilbilane by hydroxymethylbilane synthase.
Then macrocycle closure by uroporphyrinogen III synthase.
Then decarboxylation by uroporphyrinogel decarboxylase to make methy groups, and hen oxidation to make vinyl groups - end product coproporphyrinogen III.
Then linkers oxidized from methyl to methine groups to make protoporphyrin IX (intermediate is protoporphyrinogen IX).
Then mitochondrial ferrochelatase adds Fe2+.
What parts of heme synthesis can be inhibited by lead?
Ferrochelatase (can result in creation of ZnPP instead).
ALA dehydrogenase can also be inhibited by lead.
When is a porphyria photosensitive?
If there is a closed ring structure.
What are the erythropoietic porphyrias?
Congenital (Uroporphyrinogen III synthase deficiency - Hydroxymethylbilane (and uroporphyrinogen I and coproporphyrinogen I accumulate))
Protoporphyria (ferrochelatase defect - protoporphyrin IX accumulates)
Skin rashes, blisters in early childhood. Eventually complicated by cirrhosis/liver failure. Photosensitive.
Describe ALA dehydratase deficiency porphyria.
Acute hepatic. ALA accumulates.
Describe acute intermittent porphyria.
Acute hepatic. Deficiency in hydroxymethylbilane synthase - porphobilinogen and deltaaminolevulinic acid (ALA) accumulate. Urine darkens on exposure to air and light. Not photosensitive.
Acute attacks of GI, neuro, and motor symptoms.
Describe Variegate porphyria.
Acute hepatic. Deficiency in protoporphyrinogen oxidase - protoporphyrinogen IX accumulates. Photosensitive.
Acute attacks of GI, neuro, and motor symptoms.
Decribe Hereditary coproporphyria.
Acute hepatic. Deficiency in coproporphyrinogen oxidase - coproporphyrinogen III accumulates. Photosensitive.
Acute attacks of GI, neuro, and motor symptoms.
Describe Congenital Erythropoetic Porphyria.
Erythropoietic. Defieicnty in uroporphyrinogen III synthase - Hydroxymethylbilane (and uroporphyrinogen I and coproporphyrinogen I) accumulate. Photosensitive.
Describe Porphyria cutanea tarda.
Hepatic chronic - the most common porphyria. Onset in 4-5th decade of life, clinical expression influenced by iron load, alcohol use, sunlight exposure, Hep B/C, HIV, estrogen therapy.
Skin eruptions, discoloured urine.
Deficiency in uroporphyrinogen decarboxylase - accumulation of uroporphyrinogen III.
Describe heme degradation.
Inside macrophages Heme oxygenase (uses NADPH) releases the iron and breaks protoprphyrin IX into biliverdin (and CO2). Biliverdin reductase (uses NADPH) reduces the bonds and produces bilirubin.
Then it travels on albumin to the liver, where propionic acids react with UDP-glucuronide and its conjugated to bilirubin diglucuronide. It’s deconjugated in the intestine and converted to urobilinogen. Bacteria mostly converted it to brown sternocobilin (excreted), but some is reabsorbed, oxidized in the kidney, and excreted as yellow urobilin.
What is neonatal jaundice and how do you treat it?
Incomplete expression of bilirubin glucuronyl transferase. Treat with UV light to make soluble bilirubin isomers.
What is Gilbert Disease?
An unconjugated hyperbilirubinemia. Familial, can occur with neonatal jaundice, yellow tinge, slight increase of unconjugated bilirubin.
What is Crigler-Najjar Disease? Describe Type I vs Type II.
An unconjugated hyperbilirubinemia. Little or no UDP glucuronyl transgerase in liver, requires lifelong phototherapy.
Type I is AR, no enzyme
Type II is AD, decreased levels, can treat with phenobarbitone
What is Kernicterus?
Bilirubin-induced brain dysfunction, can occur in newborns.
What is Dubin-Johnson Syndrome?
A conjugated hyperbilirubinemia. Defective bilirubin secretion from hepatocytes into bile (dark brown liver)/
What is Rotor Syndrome?
A conjugated hyperbilirubinemia. Transporter defect in hepatocytes, mild elevation of conjugated bilirubin.
Describe how IMP (purine precursor) is synthesized? How are the relevant enzymes regulated?
Glucose to R5P via PPP to PRPP by PRPP synthetase (activated by Pi, inhibited by IMP/AMP/GMP).
PRPP to IMP by phosphoribosylphosphate amidotransferase (activated by PRPP, inhibited by IMP/AMP/GMP)
What do sulfonamides do?
Inhibit bacterial folate synthesis.
How does IMP turn into AMP?
Adenylosuccinate synthase (uses Asp, GTP) to make adenylosuccinate, and then adenylosuccinase to remove a Fumarate and make AMP.
How does IMP turn into GMP?
IMP dehydrogenase (makes an NADH, neg feedbacked by GMP) to make Xanthosine MP. Then GMP synthase to turn Gln into Glu.
What does mycophenolic acid do?
Block IMP dehydrogenase - is an immunosuppressant.
How are purines converted to uric acid?
Ps removed, riboses removed. Hypoxanthine and guanine further converted to xanthine which is converted to uric acid (both done by xanthine oxidase).
What enzyme turns adenosine to inosine and AMP to IMP? What’s special about it?
Adenosine deaminase.
Lack of it causes SCID.
How is adenine recycled back into AMP?
Via APRT (adenosine phosphoribosyl transferase) at the cost of a PPRP.
How is guanine recycled back int GMP?
Via HGPRT (hypoxanthine guanine phosphoribosyl transferase) at the cost of a PPRP.
What is Lesch-Nyhan syndrome?
X-linked HGPRT loss. Increased PPRP levels and stimulation of de novo purine synthesis - gout and mental aberrations.
What are the dietary risk factors for gout?
Meat, seafood, ethanol.
How is gout treated?
Antiinflammatory agents (colchicine, prednisone, indomethacin).
Allopurinol to lower synthesis (competitive inhibitor of xanthine oxidase, metabolized to oxipurinol which is also an inhibitor).
What is 6-mercaptopurine?
An antimetabolite - a xanthine analog, competes with HGPRT and is used with methotrexate.
What is azaserine?
An antimetabolite - a glutamine analog, blocks glutamine PRPP amidotransferase.
What are methotrexate and aminopterin?
Folic acid analogs - antimetabolites.
Describe de novo pyrimidine synthesis.
Gln and CO2 and 2ATP made into carbamoyl phosphate by CPSII (downregulated by UTP, upregulated by PPRP).
Carbamoyl phosphate made into carbamoyl Asp by Asp transcarbamoylase. Carbamoyl Asp made to dihydroorotate by dihydroorotase.
Dihydroorotate made into Orotate by dihydroorotate dehydrogenase.
Orotate made into OMP (orotidine 5’MP) by orotate phosphoribosyl transferase.
OMP made into UMP by OMP decarboxylase.
What are the symptoms of orotate aciduria?
Orotate in urine, megaloblastic aemia, poor growth.
How is UTP made into CTP?
CTP synthetase (converts Gln into Glu).
How is dUMP made into dTMP?
Via thymidylate synthase (needs THF for process).
How does 5-fluorouracil affect nucleotide synthesis?
Is a thymidylase synthase suicide inhibitor - makes 5F-dUMP.
How are deoxyriboses made from riboses?
Via ribonucleotide reductase.
Uses reduced thioredoxin, which is regenerated by thioredoxin reductase at the cost of an NADPH.
Generally describe Type I hypersensitivities.
Sensitization (IgEs produced and bind to mast cells)
Challenge (Ags bind to IgEs, IgEs cross link and bind to FCepsilonRI receptor on mast cell/eosinophil/basophil, triggers degranulation)
What is atopy?
A genetic predisposition to Th2 response and IgE production.
What types of antigens make allergens?
Proteins or chemicals that modify human proteins.
How do basophils drive Th2 response?
By IL-4 and IL-13 production.
What do you look for in the blood to determine a type I hyperimmune reaction?
Tryptase. Has a long t 1/2.
Describe phase 1 of IgE-caused mast cell enzyme release.
Histamine, heparin (toxic to parasites, increases vascular permeability, SM contraction).
Also tryptase, chymase, cathepsin G, carboxypeptidase (remodels CT matrix).
Describe phase 2 of IgE-caused mast cell enzyme release.
TNFalpha is released (some was preformed in granules). It causes inflammation, cytokine production, activates endothelium.
Also IL-4, IL-13,
IL-3, IL-5, and GM-CSF (eosinophil production and activation), CCL3, LTC4, D4, E (SM contraction, vasc. permeability, mucus secretion), and PAF.
What is RAST allergy test?
Radioallergosorbent test. In vitro.
Insoluble antigen incubated first in test serum and then in radiolabeled anti-human IgE. Then enzyme fluorescence is quantified.
What are the effects of type I hypersensitivity?
Increased GI peristalsis and fluid secretions, decreased airway diameter, increased mucus, increased blood vessel permeability.
What is an anaphylactoid reaction?
Mast cell degranulation that is IgE independent.
How do you treat type I hypersensitivity and anaphylaxis?
Antihistamines, anti-LTs, corticosteroids, cromolyn sodium, Epinephrine (IM E is treatment for anaphylaxis).
Describe type II hypersensitivity.
IgG binds Ag that is on cell, complement/MAC causes cell death.
What kind of hypersensitivitiy reaction can penicillin trigger?
Type I (other haptens ca do this too) and II (can modify cells to display foreign Ag).
Binding of Abs to penicillin-modified RBCs makes them susceptible to complement-mediated lysis or phagocytosis via Fc and complement receptors.
Describe a type III hypersensitivity.
Immune complex mediated. Soluble Ag bound, complex deposited, then there is chemokine-neutrophil activation.
How are immune complexes normally cleared?
RBCs bind via CR1 and take them up.
What is serum sickness?
Systemic inflammation reaction due to immune complexes in many parts of the body. Has limited duration, used to be caused by horse serum IgGs.
What is arthus reaction?
(Type III). Soluble antigen subcutaneously injected into a sensitized person (already had preexisting Abs).
What is SLE?
Abs to nuclear antigens.
What is poststreptococcal glomerulonephritis?
Immune reaction to strep cell wall antigens after an infection - causes kidney disease.
What is polyarteritis nodosa?
Systemic vasculitis caused by immune reaction to Hep B antigens.
What is reactive arthritis?
Immune reaction to bacterial antigens.
Describe type IV hypersensitivity.
Delayed. T cell associated. Th1 for soluble Ags, CD8 for cell-associated ones. Effector cells largely macrophages.
Th1 releases chemokines (recruits macrophages), IFNgamma (activates macrophages and increases release of inflammatory mediators), TNFalpha and LT (adhesion molecules on local BVs), IL-3 and GM-CSF (monocyte production in BM).
Describe poison ivy/oak reaction.
Type IV hypersensitivity to pentadecacathenol. Crosses PM and modifies IC proteins.
1st exposure minor and undetectable, 2nd onward has memory Th1 and CD8 cells. Lesions due to heavy leukocyte infiltration.
Describe the tuberculin skin test.
A type IV hypersensitivity. TB Ags put in intradermally, reaction 24-72 (mean 48) hours later.
What are the requirements for pathologic autoimmunity?
Immune reaction to self Ag/tissue, evidence that the reaction is not secondary to tissue damage, absence of another cause of disease.
Are men or women more prone to autoimmune illness?
Women.
Describe the antibodies in rheumatoid arthritis.
Anti-CCP Abs. Affiliated with DRB1 alleles (HLA). 4 and 12 OR respectively depending on 1 or 2 alleles.
Describe the genetics that predispose someone to ankylosing spondylitis.
B2075 and B2072 B*27 alleles (HLA). 100-200 OR.
What ANAs are in SLE?
Native DNA (40-60% cases), Anti-Sm (30-40%), U1RNP (30-40%)
What ANAs are in drug-induced LE?
Histones (>95% cases).
What ANAs are in Systemic Sclerosis?
Sci-70 Ab (Topoisomerase I) (28-70% cases).
What ANAs are in Limited Scleroderma/CREST?
Anticentromere (90% cases).
What ANAs are in Sjogren syndrome?
SS-A (Ro) (70-95% cases) and SS-B (La) (60-90% cases).
RNPs.
What does a homogenous indirect immunofluorescence ANA pattern mean?
Abs to chromatin and histones.
What does a rim indirect immunofluorescence ANA pattern mean?
Abs to dsDNA.
What does a centromeric indirect immunofluorescence ANA pattern mean?
Abs to centromere.
What does a speckled indirect immunofluorescence ANA pattern mean?
Abs to non-nuclear components like Sm, SS-A, SS-B.
What does a nucleolar indirect immunofluorescence ANA pattern mean?
Abs to RNA.
How can you tell apart chronic discoid lupus (DLE)?
Normal skin shows no Abs, skin manifestations without systemic manifestations.
Describe subacute cutaneous Lupus and Drug induced LE.
Widespread superficial skin rash, mild systemic symptoms consistent with drug induced LE.
Drug induced has anti histone ABs, rash, serositis, arthralgias, fever, is associated with HLA DR4. Drugs that can cause it are hydralazine, procainamide, isoniazid, alphapenicillamine.
Describe Sjogren syndrome.
AKA Mikulicz syndrome. Mostly in women 50-60. Dry eyes (keraconjunctivitis sicca), dry mouth (xerostomia), generally another autoimmune disease. Primary form is sicca syndrome. Lymphocytic infiltration and fibrosis of lacrimal and secondary glands. Confirmed with biopsy of lip (look at minor salivary glands).
What is CREST?
Part of systemic sclerosis/scleroderma. Calcinosis (calcium in skin), Raynaud’s phenomenon (red/white/blue hands in response to cold/stress), Esophageal dysfunction, Sclerodactyly, Telangiectasis (dilation of capillaries causing red marks on skin surface).
Describe diffuse vs limited scleroderma.
Limited is that skin involvement is confined to fingers, forearms, face. Difuse is widespread skin involvement at onset and rapid progression and early visceral involvement.
What is the most common mutation causing scleroderma?
Fibrillin 1.
What is orthotopic vs heteroropic transplantation?
Put into the same location vs put into a different location.
What’s the difference between hyperacute and acute rejection?
Hyperacute is minutes to hours and is mainly a type III sensitivity. Recipient must have been previously sensitized.
Acute is days-months and mainly a type IV hypersensitivity. Interstitial mononuclear infiltrate usually appears a month after transplant. APCs present Ag to T cell.
What’s direct vs indirect allorecognition?
Direct is donor graft DC presents the donor peptide, indirect is the recipient DC.
How is the survival of grafts that lack lymphatic drainage?
Better.
What are the transplant requirements?
HLA matching, ABO matching, cross matching (add donor cells to recipient plasma).
Describe HLA matching.
D must match, +2 must match (B>A/C). Look for least mismatch.
What is an antiinflammatory agent given for transplant?
Prednisolone
What are cytotoxic agents given for transplant?
Azathioprine, mycophenilate mofetil, cyclophosphamide, methotrexate
What are T cell activation inhibitor agents given for transplant?
Cyclosporin A, tacrolimes(?), rapamycin, anti-TCR, anti-CD3
What kind of transplants can cause chimerism?
Hematopoietic stem cell.
What are the screening tests for B cell defects?
B cell count, quantitative Igs, isohemagglutinins (anti-A/Bs).
What are the screening tests for T cell defects?
Total lymphocyte count, lateral chest xray (for infants), delayed hypersensitivity skin test (for >2 y/o).
What are the screening tests for neutrophil defects?
WBC and differential CBC, nitroblue tetrazolium dye test, chemotaxis, chemoluminescence/flow cytometry.
What are the screening tests for complement defects?
Total hemolytic complement test - CH50, C1 INH, C3, C4, C8.
Describe transient hypogammaglobulinemia of infancy.
3-9months is a physiological phase of hypoIgs - maternal IgGs mostly have been catabolized by 6 months.
Describe X-linked/Brutons hypogammaglobulinemia.
Mutation in Bruton TK (long arm of X-chrom), problem is signalling through preB cell receptor (cannot mature).
No/few mature B cells, no IgGs, small LNs, no tonsils. ~20% go onto develop autoimmune diseases, extreme susceptibility to pyogenic bacterial infections at 4-8months.
Treat with IVIgs.
Describe hyperIgM syndrome.
X-linked, CD40/CD40L/AID issue, macrophage function also impaired.
Describe selective IgA Deficiency.
Most common immunodeficiency (~20% also deficient in IgG2 and IgG4).
Recurrent infections, allergy, autoimmune disease.
Don’t give IgAs!!! Can cause serum sickness!
What other cell type is affected in a T cell deficiency?
NK cells.
Describe DiGeorge Syndrome. How do you treat it?
22q11.2 deletion - defect on 3rd and 4th pharyngeal pouch development - no thymus or parathyroid glands.
Few/no T cells - B cells present but of variable function. Postnatal hypocalcemic tetany/seizures, CHF (outflow tract defects), developmental delay, hyperactivity, craniofacial deformities (low ears, wide and slanting down eyes, cleft palate, short philtrum, bifid uvula, fish mouth).
Give Calcium, VitD, PTH.
Describe Wiscott-Aldrich Syndrome. How do you treat it?
X-linked (WASp gene on short arm of X). Sialophorin/CD43/WASp affected (cytoskeleton of lymphoid cells). Affects B cells, T cells, platelets.
Thrombocytopenia, defective T cells, often IgM deficiency (normal IgGs, increased IgA/E). Severe eczema (atopic dermatitis).
Give PLT transfusions, do splenectomy (bleeding), antibiotics, IVIg, avoid frequent baths, use bath oils and moisturizing creams, avoid offending foods. BM transplant is curative.
How do people die from Wiscott-Aldrich Syndrome?
Bleeding (very young), infection (children), lymphoid malignancies (adolescent/adult).
What are the inheritances of SCIDs?
75% X-linked, 25% AR.
How do you treat SCIDs?
Antibiotics, IVIg, prophylaxis for pneumocystis jirovecis (trimethoprim-sulfamethoxazole).
BM transplant curative.
Describe X-linked SCI.
T cells lack gamma chain of IL-2 receptor.
T and NK -
B +
Describe Adenosine Deaminase deficiency. How do you treat it?
Most common AR SCID. Defective enzyme in purine salvage pathway - accumulation of dATP/dAdenosine. T,B,NK -. Abnormal bone development.
Give polyethylene glycol-modified bovine ADA. BM tranplant curative.
What does a defect in C3 cause?
Decreases opsonization. Increased susceptibility to encapsulated bacterial infection.
What does a defect in C5-9 (MAC) cause?
Increased susceptibility to disseminated Neisseria infections.
What does a defect in CD18 cause?
Decreased margination, diapedesis, increased leukocytosis (but no leuks at the infection site/inflammatory response at site).
What is chronic granulomatosis disease?
X-linked NADPH oxidase deficiency.
Persistent lymphadenopathy, recurrent abscesses, frequent pneumonia, low NBT, normal chemotaxis.
What is Chediak-Higashi disease?
Defect in neutrophil - poor organelle trafficking/vesicle fusion. No enzyme release.
Recurrent infections, albinism, ataxia, persistent lymphadenopathy, low NBT, low chemotaxis.
What is the host of plasmodium berghei?
Rats.
What is the host of plasmodium yoelii?
Mice.
What is the host of plasmodium knowlesi?
Monkeys.
What are the hosts of Plasmodium malariae?
Sporogony cycle is female anopheles mosquito. Schizogony cycle is vertebrates.
Describe the life cycle of Plasmodium malariae.
Sporozote enters human and replicates in liver parenchymal cells. Schizont forms and ruptures, releasing merozoites.
Merozoites enter RBCs, schizont forms, cycle repeats, Eventually gametocyte forms and a mosquito ingests that to complete sporogenic cycle.
What are the symptoms of malaria?
Fever, nausea, vomiting, headache, body aches, malaise/weakness.
Malaria is considered uncomplicated if there is no organ involvement.
What are the fever spike paterns of Plasmodium malariae, vivax, and falciparum.
Malariae - quartan
Vivax - tertian
Falciparum - malignant
How can you diagnose malaria?
Blood smear (parasite in RBCs), HRP2 detection, parasite LDH.
What are some protective factors against malaria?
Absence of receptor, G6PD deficiency, Sickle cell trait, Thalassemia.
What is the Plasmodium vivax receptor?
Duffy Ag
What are hypozoites?
Get latent in the liver - P. vivax, P. ovale.
What is recrudescence vs relapse?
Recrudescence is recurrence of symptoms after temporary abatement (days, weeks).
Relapse is return of disease after resolution of primary infection.
What is the vector is babesiosis?
Ixodes ticks.
What are the babesiosis species that we care about?
Babesia microti, Babesia divergens.
What are the symptoms of babesiosis?
Usually none unless hte person is immunocompromised or splenectomised.
How do you diagnose babesiosis?
Blood smear (tetrads/maltese cross).
Clindamycin+quinine, entovaquone+azithromycin.
What are the genomes of viral hemorrhagic fevers?
enveloped, (-)ssRNA
Except Flaviviridae - (+)ssRNA
How do you treat viral hemorrhagic fevers?
Antipyretics, Analgesics (not salycilates), fluid management
Ribavirin and passive immunity (Arenaviridae).
Describe Flaviviridae - vector, illnesses.
Vector Aedes spp. Reservoir is primates (humans are accidental host).
Yellow Fever (biphasic symptoms - 24-48hr pause).
Dengue (normal or severe phase)
Zika (Aedes aegypti - in fetuses can cause microcephaly/Guillain-Barre, in adults microcephaly/rash).
Describe Filoviridae - vector, illnesses.
Reservoir is bats, can also get from direct contact with fluids of infected hosts.
Species Marbury and Ebola (subspecies Zaire, Sudan, Cote d’Ivoire, Reston(not pathogenic in humans))
Describe Bunyaviridae - vector, illnesses.
Insect vectors, direct contact with body fluids. Reservoir is rodents, sheep, cattle.
Hanta Pulmonary Syndrome (late symptoms - coughing, SOB, edema) CFR 38%
Hanta Fever w/ Renal Syndrome (early symptoms - petechial rash, bilateral conjunctivitis, flushing, blurred vision, others; late symptoms - low BP, vasc leakage, kidney failure, shock)
Describe Arenaviridae - vector, illnesses.
Transmission by aerosols/droplets, dust. Reservoir is rodents.
Neurologic (LCMV) - aseptic meningitis, encephalitis, meningoencephalitis (CFR <1%)
HF: fever, headache, dizziness, asthenia, pharyngitis, cough, vomiting, retrosternal andp haryngeal pain, confusion, convulsion/coma, ARDS. CFR 5-30%
What are amastigotes and trypomastigotes?
Parasite forms found in tissues/within cells and free in blood respectively.
Describe African Tryponosomiasis.
Sleeping sickness - Trypanosoma gambiense and Trypanosoma rhodiense. Vector is tsetse fly.
Describe American Tryponosomiasis.
Chagas’ Disease - Tryponosoma cruzi. Reduviid bug via animal.
ENlarged heart and intestine, facial edema (Romana sign).
Where are amastigotes found in Leishmania sp.s?
Macrophages.
What is the vector for Leishmania sp.s?
Phlebotomus sandfly.
What kind of Leishmaniasis is gotten from L. tropica?
Dermal cutaneous or diffuse cutaneous form.
What kind of Leishmaniasis is gotten from L. brasiliensis?
Musculocutaneous form.
What kind of Leishmaniasis is gotten from L. donovanii?
Most severe visceral form.
Irregular fever, weight loss, anemia, hepatosplenomegaly. Pancytopenia (high putput HF) - myocarditis, pericarditis. Fever, cachexia, hypergammaglobulinemia, hypoalbuminemia.
Amastigotes in deep tissue - liver, spleen, BM.
Treat with pentosan, glucantine, allopurinol, miltefosin.
Describe Entamoeba histolytica.
Fecal-oral transmission cycle parasite. AIDS patients susceptible. Chlorine resistant.
Intestinal dissease, extraintestinal spread, liver abscesses, rupture, then pericardial disease.
Describe Toxoplasma gondii.
Cat is definitive host, many vertebrates are intermediate.
Fecal-oral transmission (of oocyte), ingestion of undercooked meat, transfusion, transplant, transplacental transmission.
Infection usually subclinical (flu-like symptoms), can be latent and reactivate - encephalitis, chorioretinitis, myocarditis, pericarditis, CHF.
What parasites cause heart issues?
Trichinella spiralis, Echinococcus granulosus (hydatid cysts), Taenia salium (cystercosis).
What parasites cause cardiac pathology via severe anemia?
Necator americanus, Acylostoma duodenale, Diphyllobothrium latum.
What parasites cause lymphatic filariasis/elefantiasis?
Wucheria bancrofti, Brugia malayi, Brugia timori.
Wolbrachia bacteria play a role in the hypereosinophilia (they’re gram(-))
How do you diagnose and treat elefantiasis?
Adult worms found in lymphatics.
Diagnose: chyluria, hypereosinophilia, ingreased IgEs, increased IgG4, increased antifilarial Abs, ELISA, card test, microfilariae blood smear.
Treat with Antihelminths (DEC, Albendazole+DEC, Albendazole+ivermectin), Antibacterials (Tetracycline, Rifampin, Doxycycline).
What does Onchocerca volvulvus cause? What’s the vector, how is it diagnosed and treated?
River blindness. Vector is simulium sandfly (mature larvae are injected subq, microfilariae released and go to skin and eye - onchodermatitis and keratitis).
Diagnose with microfilariae in skin nip, slit lamp microscopy.
Treat with DEC, Ivermectin, Suramin/Antrypol.
What’s the structure of retroviridae?
Diploid (+)ssRNA, enveloped icosahedral capsid.
Are retroviridae lytic?
No.
What is HIV p24?
Capsid protein.
What is HIV gp41?
HIV TM protein - does fusion.
What is HIV gp120?
HIV surface protein.
What are the genes in all retroviridae?
Gag, Pol (has IN and RT), Env.
What are the two forms of HIV?
M-tropic/CCR5 (mostly responsible for transmission, goes into macrophages)
T-tropic/CXCR4 (mostly responsible for progression to AIDS).
How does HIV get to T cells?
DCs internalize it (DC-SIGN protein has affinity for gp120) then it meets CD4 T cells in LNs.
What is an ‘inverted ratio’ as it pertains to HIV?
CD8:CD4 2:1.
How do you diagnose HIV?
Screening ELISA (p24), confirm with western blot (must have 2 or more of p24, gp41, gp120, gp160).
What are the phases of untreated HIV infection?
Acute: CD8 high, CD4 drop, lots of RNA copies, HIV-Abs start building.
Asymptomatic: HIV-Abs stay constant, RNA drops low then stays constant, CD8 stays constant, CD4 drops.
AIDS: CD4<400, RNA increases.
Which lines of HTLV are cell transforming?
HTLV1 and HLTV2.
How is HTLV1 transmitted and what disease does it cause?
Transmitted by breastfeeding, blood transfusion/needle sharing, sex.
HTLV1-associated myopathy/topical spastic paraparesis. Associated with alveolitis, polymyositis, dermamyositis, arthritis, ovestra, dermatitis.
Has been linked to Adult T-cell Lymphoma (ATL).
How is HTLV diagnosed? How is it treated?
Diagnosed with ELISA screening for HTLV1-Abs (particle agglutination also used), and WB or RTPCR to confirm.
ATL found to have ‘flower cells’.
Treat with combination chemo, ART/IGNalpha/chemo, hematopoietic cell transplant.
What is the difference between hyperemia and congestion?
Hyperemia is an increase of blood in arteries, congestion is increase of blood in veins.