1、NPLEX Combination ReviewImmunology/ToxicologyPaul S.Anderson,NDMedical Board Review ServicesCopyright MBRSLaboratory Testing Methodologies PCR:Polymerase Chain Reaction ELISA(Enzyme Linked Immunosorbant Assay)Measures IgG/M/AUsed in disease detection and Allergen identification.RAST Quantifies IgE a
2、ntibodies.Intradermal testing Positive reaction demonstrates erythema at point of injection.Blood immunoglobins IgG Delayed hypersensitivity reaction to antigen.IgE Immediate hypersensitivity reaction to antigen.Electrodermal allergy test EAV is appropriate example.ID Immunology:General Cultures Tak
3、e time Some things grow,some dont Antibody Testing Good for effect Some better than others DNA(PCR)Testing Detects DNA of the subject of the probe No need for growing a culture No need for Ig interpretation Can get Quantitative(viral load)testsAntibody Testing Serum tests.Serum must be separated fro
4、m clot/SST Gel within 1 hour!Pipette serum into a plastic transport tube Excessive exposure to the gel in the SST will bind antibodies,causing false negative tests.Used for allergy testing,Autoimmune testing,Exposure Ig(Immunoglobulin)Types:IgG:Long term exposure,Delayed reactions(ie.Food allergy).I
5、gG lasts a long time,and is a marker of EXPOSURE,not successful treatment.IgM:Acute phase reactions.Indicates recent infection or re-exposure.IgA:Secretory Ig.Shows mucosal response,and is a good marker of successful treatment.Can be measured in the serum,stool and saliva IgE:Anaphylaxis.(Type-1 Rea
6、ction).Total IgE in serum is a test for general allergic level in the patient Traditionally the marker used for food and Inhalant allergy,although IgG is more helpful with most food reactions.Antibody Testing-2 High IgG,Low IgM or IgA Probable past infection/exposure.Inactive or cured.In food allerg
7、y testing IgG is always considered active,but delayed response allergy.Low IgG,High IgM New infection/Exposure High IgG,High IgM Reactivated infection/Exposure High IgG,Low IgM,High IgA Current immune response(mucosal)that is past the initial IgM response window.(On going problem).Autoimmune Disorde
8、rsAnti-nuclear antibody(ANA)Titer level is important:1:160“positive”Screening test for connective-tissue diseases:RA,SLE,Lupus,MCTD,CREST Syndrome,Scleroderma,and Polymyositis.Use confirmatory ANA sub-testing to confirm specific disease Dx.Often ordered as ANA+Reflex(7 or 9 values)run if ANAA is pos
9、itiveErythrocyte Sedimentation Rate(ESR)Nonspecific measure of inflammation Diagnostic in very few conditions(Giant cell arteritis)Can also indicate cancerous effectC-reactive protein(CRP)Screening for nondescriptive inflammatory and infection disease processes.Also used for discriminating among DDX
10、 and monitoring disease process CRP elevation:RA,Reiters,vasculitis,rheumatic fever,neonatal and post-operative infections,pyelonephritis,MI and embolism.Autoimmune DisordersRheumatoid factor(RF)Used in the diagnosis and evaluation of RA and other CTD;Highest in RA,but also elevated in CVD,MI,renal
11、disease,malignancy,thyroid and liver disease,SLE,scleroderma and polyarteritis nodosa.Parvo B-19 viral assay Consider in RF Negative woman nursing or caring for a young child who presents with RA like symptoms.Human leukocyte antigen(HLA)HLA B-27 most common.Glycoproteins that may be serologically d
12、etermined;usually performed for transplantation matches but also elevated in AS,Reiters Syndrome,MS,chronic active hepatitis,gluten-sensitive enteropathy,SLE,DM and hemochromatosis.Consider Chlamydia testing (Reiters)Autoimmune DisordersAnti-thyroid antibody(Anti Microsomal or TPO Ab)Used in diagnos
13、is and classification of inflammatory and autoimmune thyroid disease.Marker for Hashimotos thyroiditis,atrophic thyroiditis,and Graves Disease.Antithyroglobulin Antibody(Anti TG)Detect and confirm autoimmune thyroiditis,Hashimoto thyroiditis Thyroid-Stimulating Immunoglobulin(Thytrophin Receptor Ab)
14、Detect Graves Dz.Order when Graves Sn/Sx and TPO elevationTHYROID HORMONE SYNTHESISInfectious Disease Testing Anti-Streptolysin-O test(ASO)(200iu/ml)Elevation in titers reflect immunologic response to streptococcus;ASO titers clinically useful if serum is obtained in 2-3 week intervals.Chlamydia ant
15、ibody(IgG,IgM)Presence of IgG Ab indicates chlamydial infection in the past;highly sensitive but has low specificity.Presence of IgM or 4-fold increase from acute convalescence=recent infection.Cytomegalovirus PCR Cytomegalovirus(CMV-IgG,IgM)Presence of IgM or 4-fold increase in IgG=recent infection
16、Infectious Disease Testing Epstein-Barr Virus(EBV)Monospot:Screening test performed with symptomatic Pt.(false negative in adults 10%).Measures IgM heterophil antibodies.Positive window:4-21 days PCR for EBV:Most sensitive test is Quantitative(viral load)PCR Used in Chronic reactivating cases EBV Pa
17、nel:Early phase IgM:anti-VCA Acute illness IgG:anti-VCA Acute illness IgG anti-EA Convalescence Anti-EBNA(Indicates past infection OR Chronic reactivation in recurrent EBV patients).E.coli O157-H7 specific assay Stool Giardia Stool assay in symptomatic patient Helicobacter pylori Multiple methodolog
18、ies:Nitrogen breath test(Sensitive for presence of dz and tx)Serum IgG:(Sensitive for PAST infection but will not decrease with successful tx.)Serum IgM:(Sensitive for current infection but will decrease in 2-4 weeks regardless of infection.)Serum,Salivary or Stool IgA:(Rises with presence of infxn/
19、falls with effective tx.)Stool IgA is preferred test now by IDSAHepatitis(A,B,C,D,E)virus HAV:IgM titers reflect acute infection.IgG titers identified years after acute illness.HBV:HbsAg:detected 14 months post-infection.Patients with this antigen present 6 months exhibit chronic hepatitis.ANTI-HBs
20、Ab:Patients with this Ab are considered protected against the HBV infection HbcAg IgM most useful marker to determine the“window”:(HbsAg disappears and ANTI HbsAg appears;usually demonstrates present infection.)The presence of ANTI HbcAg IgG indicates previous HBV infection and persists indefinitely
21、.HCV Ab Patients with this Ab have four-fold increase for HCC HCV PCR is available as well.HDV-co-exists with hepatitis b infection.Maked Hep-B more deadly.Worst in pregnancy.HEV Not generally tested for:cases out of U.S.Test if foreign travel in the past 60 days Herpes simplex virus(HSV-1;HSV-2)Ant
22、ibodies:IgM Current infection.IgG Infection in the past.IgG/M Type(1or2)specific serology is best DDX PCR is available Virus isolation(Tzank smear)is OLD method to confirm an HHV infection:Can have false positives if other HHV infection is present NOT specific to HHV 1 or 2 Generally*HSV 1 above wai
23、st while HSV 2 affects below waist.But this is not always the case.Human Immunodeficiency Virus(HIV)Standard method for diagnosis:ELISA measured anti-HIV titers.Confirmed by Western Blot Analysis.(MAY TAKE 6 MONTHS TO SERO-CONVERT)Decreased CD4/CD8 ratio Newly diagnosed condition:T-Cell subset(CD3,C
24、D4,CD8).Earliest diagnosis:PCR for HIV Human Papilloma Virus(6,11,16,18,31,33)HPV 16,18,31,33 are common causes for cervical cancer.Available as PCR on Pap sample HPV 6,11 common causes for plantar and genital warts.NOT generally cancerous or pre-cancerous Rubella titer Presence of IgM and/or four-f
25、old increase in IgG=present infection.Syphyllis(VDRL/RPR)Nontreponemal tests used primarily for detection of primary syphilitic infection.Tuberculosis Intradermal skin test:Read 48-72 hours for induration.BCG:Post ID;check serology results.Lyme disease(250 antibody reaction units)Skin,blood,synovial
26、 or CSF.ELISA or Western blot checking for antibody detection.PCR Now availableAntimicrobial and Dermatologic PharmacologyAntifungal,helminthic and protozoal PharmacologyAntifungalsMOAUsesAdverse EffectsOtherNystatinDisrupts fungal cell wallIntestinal,cutaneous,vaginal and mucocutaneous infections c
27、aused by CandidaContact dermatitisPoorly or not absorbed.Good topical agent/GI Agent.MiconazoleDisrupts fungal cell wallTinea pedis,cruris,versicolor,corporis,cutaneous candida infection and vulvovaginal candidiasisPruritus,skin irritation,burning,contact dermatitisClotrimazoleDisrupts fungal cell w
28、all“Nausea,vomiting,vaginal burning or irritation with application,erythema,pruritus,increased liver function testsGriseofulvinFungicidal Tinea pedis,tinea unguiumAlso Tinea corporis,capitis and crurisHeadache,dizziness,GI upset,nausea,vomiting,rash,urticaria,hepatic toxicTeratogenicBoric AcidFungas
29、tatic agentVaginal candidiasisLocal irritationGentian VioletFungicidalOral CandidaMouth rinse,may stain skin or clothingDo not use on ulcerative wounds on the faceAcetic AcidVoSol OticInhibits or destroys bacteria in the earOtic solution for external ear infectionsEar irritation,urticariaANTIFUNGAL
30、DRUGS-2 Amphotericin I.V.Only(unless compounded)Two types Strong/High potential side effect profile(I.V.)Triazole class Fluconazole (Diflucan)Inhibits Fungal p-450,degrading fungal cell wall Ketoconazole (Nizoral)Itraconazole (Sporonox)Voriconazole (V-Fend)Terbinafine(Lamisil)Topical and Oral formsN
31、ystatin Multiple forma available.Topical kill even in the GI tract.GI Infections:500,000 1 Million Units po tidFluconazole Absorbs so more systemic kill and more systemic side effect.Primary site of activity Liver Dosing strategies vary widely based on immunocompetence and type of infection.May be a
32、s low as 150-200mg in a single dose for uncomplicated fungal vulvovaginosis to as much as 200 mg bid for long term(2-4 weeks),or 100mg daily for months.If using it long term I normally treat on a 5 days on/2 days off rotation.Terbinafine Fingernail onychomycosis:250mg qd for 6 weeks Toenail onychomy
33、cosis:250mg qd for 12 weeksANTIPARASITIC DRUGSTopicalMOAUsesAdverse EffectsOtherLindaneKwellPenetrates exoskeleton inducing seizures and death of arthropodsScabies,pediculosisSeizures,irritation,CNS disturbancePermethrinElimite/Nix Causes paralysis by disrupting sodium current in the parasiteScabies
34、,pediculosisPruritus,edema,rash,burning,or stingingAntihelminthicsMOAUsesAdverse EffectsOtherMebendazoleVermoxIrreversibly inhibits nutrient uptake by helminthesPinworms,roundworms,hookwormsAbdominal pain,diarrhea,feverMebendazole Pinworm:100mg po as a single dose.Repeat in 2-3 weeks Roundworm,Whipw
35、orm,Hookworm:100mg po bid X 3 days Repeat in 3 weeksAntiprotozoalMOAUsesAdverse EffectsOtherMetronidazoleInhibits DNA synthesis in microorganism causing cell deathAmoebas,trichomoniasis,giardiaGI distress,seizures,ataxia,cramping,rash,joint pain.*Do not take with ETOH(acts like Antabuse)Potentates d
36、rugs metabolized by P450 system;AntimalarialMOAUsesAdverse EffectsOtherChloroquineUnknown Malaria,extraintestinal amebiasisHeadache,dizziness,pruritus,neuropathy,seizures,retinal changes and ototoxicQuinineUnknownMalariaExtremely toxic,cinchonism,shockANTIPARASITIC DRUGS Amebicide Iodoquinol Metroni
37、dazole(Flagyl)Paromomycin sulfate(Humatin)Anti Pneumocystis Atovaquone(Mepron)Pentamidine isethionate(Pneumopent)ANTIPARASITIC DRUGSMetronidazole Intestinal amebiasis 750mg po bid 5-7 days,then iodoquinol Rx.Trichomoniasis 750mg po tid X 7 days OR 1 gram po bid X 1 day:Repeat this dose Rx in 4-6 wee
38、ks.Bacterial vaginosis 500mg po bid X 7daysAntibiotic PharmacologyAntibiotic classes and Targets Bactericidal antibiotics that target bacterial cell wall;penicillins,cephalosporins or cell membrane;polymixins or interfere with essential bacterial enzymes;quinolones,sulfonamides usually Bacteriostati
39、c ABX are those which target protein synthesis;aminoglycosides,macrolides and tetracyclinesAdapted from:Finberg RW,Moellering RC,Tally FP,et al(November 2004).The importance of bactericidal drugs:future directions in infectious disease.Clin.Infect.Dis.39(9):131420.doi:10.1086/425009.PMID 15494908.AN
40、TIMICROBIAL OVERVIEW(Gent./Tobra.&Streptomycin)(-floxacins)macrolides quinolonesSo,Lets talk about side effects and antibiotic prescriptions:Antibiotics:GI Tract Symbiotic beneficial flora kill Overgrowth of flora-dysbiosis Pseudomembranous Colitis(C.diff)Kidneys Most ABX are polar.Lots of Ki excret
41、ion Often in IV use they can cause Ki failure if administered improperly Liver Liver effect possible,but less common than Ki“Superinfection”Systemic infection with bacteria or fungi that are not effected by the ABX you have given like a systemic dysbiosis.ABX and“Good Flora”Supplements ABX given wit
42、h beneficial flora supplements(acidophilus,bifidus)will kill many of those bugs as well.Some wait to repopulate the gut until after the Rx.If you are concerned that the patient will get too behind(ie too much good flora kill)you may supplement beneficial flora during the ABX course,AND after.If doin
43、g this DO NOT have the patient take the good flora supplement while the ABX pills are in the stomach.Alternate time of dose between flora and ABX.PenicillinMOAUsesAdverse EffectsOtherPenicillin (Pen Vee-K)Break down/Inhibit bacterial cell wall synthesisGram+cocci,anaerobic bacteria,syphilisNausea,vo
44、miting,rash,seizures,anaphylaxis,neurotoxic,nephrotoxicNot effective against -lactamase producing organism or Gram anaerobesAmpicillinInhibits cell wall synthesisSome Gram+and Gram organisms,prophylaxis for dental proceduresNausea,vomiting,diarrhea,seizures,rash,urticaria,anaphylaxisNot effective ag
45、ainst -lactamase producing organismAmoxicillinInhibits cell wall synthesisSome Gram+and Gram organisms,prophylaxis for dental procedures“Amoxicillin and ClavulanateAugmentinInhibits cell wall synthesis and Clavulanate makes it effective against -lactamase producing organismsGram+,Gram-,and -lactamas
46、e producing organism“NOTE:All Rxs are for the longer term (i.e.10 day instead of 7 day).Some INDICATIONS REQUIRE FEWER Tx days see Sanford Guide etc.All are in Adult Doses unless otherwise noted.An“Adult”is a 150 Pound HumanRx:Adult:PEN-VK 500mg tablets#30 Sig:1 po tid Child:Amoxicillin(Or Amox/Clav
47、)80-90 mg/kg of the amoxicillin component in daily divided doses.Rx X 7-10 daysCephalosporinsMOAUsesAdverse EffectsOtherCephalexinKeflex 1st generationBactericidal by inhibiting cell wall synthesisURI,GI infections,cutaneous infections,soft tissue infectionsNausea,diarrhea,maculopapular rash,anaphyl
48、axis,serum sickness,GI distress10-15%of patients have cross allergy between penicillin and cephlosporinsCefaclorCeclor2nd generation“UTI,URI,OM“CefiximeSuprax3rd generation“More resistant to Gram-lactamase producing organism“CefepimeMaxipime4th generation“E.coli,Proteus,K.pneumoniae,Enterobacter,B.f
49、ragilis,Staph/Strep“IV Dose formRx:Cefalexin 500 mg#30 Sig 1 po q-6-h Cefaclor 500mg#30 Sig 1 po q-8-hMacrolidesMOAUsesAdverse EffectsOtherErythromycinInterferes with bacterial DNA synthesisDrugs of choice for M.pneumonia,pertussis,neonatal C.pneumonia Strep throat,URI,Abdominal pain,nausea,diarrhea
50、,vomiting,anaphylaxisContraindicated in Pregnancy;caution with impaired renal functionClarithromycinBiaxin“BronchitisNon-gonococcal urethritis,cervicitis,chanroid“SAMEAzithromycinZithromax“LESS GI effect,Less medication needed to achieve effect.SAMERx:Erythromycin 333mg#30 Sig 1 tid (I use this as i
