182. Immunocompromised Pt Flashcards
Innatve vs acquired immunity basic differences?
innate - occur regardless o fhow often infection and get activated immediately
acquired - take some time after repeat exposure and 3-5d to mount
Nonmicrobe sp immunity: Physical barrier examples
skin
mucosa
cilia
biofilm
gastric acid
antimicrobial peptides
pro on skin and mm
Nonmicrobe sp immunity: Physical barrier what impairs these?
smoking
pulmonary disease
mechanical ventilation
tracheostomy
abnormal peristalsis
Initial inflammatory response and innate immunity: goal of this and microbes to do it?
promote phagocytosis and microbial killing while activating the immune system
inflammatory response to release CK - cause migration and adhesion of PMN and monocyte to bacterial invasion
Nonmicrobe sp immunity: Reticuloendothelial system
composed of tissue macrophages and blood borne counterparts, monocytes - removes particulate matter from lmph and blood
particlarly LN, spleen, liver, marrow, lung
Nonmicrobe sp immunity: Reticuloendothelial system - particular good for which bacteria?
encapsulated
pneumococci, meningococci, H influ
Adaptive/Microbe specific Immunity: Humoral: Antibody - which cells are these and what can they do?
B cell, also help to present to T cell
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: which is first to appear in system in response to new Ag?
IgM
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: IgM vs IgG
IgM: first, less affinity but provides some recognition to b cell prolif prior to making IgG
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: IgA - where do you typically find this one?
GI
nasal and oral secretions
tears
other mucous fluids
bacterial, viral and protozoan
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: IgE.- where is this?
mast cell surface, basophils
hypersen responses
particular helminth
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: IgG - how much accounts for total Ig mass?
75%
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: IgG - can it cross the placenta?
yes
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: IgG - how long does fetus have mums IgG?
first 6mo
Adaptive/Microbe specific Immunity: Humoral: immunoglobulins: IgG - G2 subtype has sp affinity for polysacc of bacterial cell capsules of which 2 bacteria in paritcular?
strep pneumoni
H influ
Adaptive/Microbe specific Immunity: Humoral: Complement: what is this?
cascade of interaction of 30 PRO to produce inflamm, leukoctyosis, recruite leukocytes to sites of infection
neutralize viruses
enhances binding of opsonin
lyses bacteria cell walls and membranes
Adaptive/Microbe specific Immunity: Humoral: Complement: which Ig activate this? (2)
IgM
IgG
classical pathway
Adaptive/Microbe specific Immunity: Humoral: Complement: what activates the alternative pathway?
repeating chemical structure molecules like bact cell wall and capsulse
Adaptive/Microbe specific Immunity: Humoral: Complement: what is the merging point of classic and alt paths?
C3
Adaptive/Microbe specific Immunity: Humoral: Complement: terminal leg of this includes C5-c9 forming the membrane attack complex - what does this do?
cell wall and membranes insertion, leads to death
In pt with mild complement deficiencies, is risk of disease with Niesseria meningitidis and gonorrhea worse or better?
milder
Adaptive/Microbe specific Immunity: In cell mediated immunity - what cells does this include?
T ymphocytes
NK
mononuclear phagocytes
Adaptive/Microbe specific Immunity: cell mediated immunity - where are most T cells?
marrow, thymus, spleen, LN
spleen and LN are where see antigens
CD4 vs CD8 roll of T cells?
cd4 help other cells including enh b cell antibody production, production of CK
cd8 kill virally infected target cells themselves
Defects in cell mediated immunity (T cells) are at risk for which disseminated infections by bacteria?
TB
Listeria
Salmonella
Defects in cell mediated immunity (T cells) are at risk for which disseminated infections by viruses?
cmv
herpses
varicella
Defects in cell mediated immunity (T cells) are at risk for which disseminated infections by fungi?
candida
cypto
aspergillus
pneumocystis
Defects in cell mediated immunity (T cells) are at risk for which disseminated infections by protozoa?
toxoplasma
2 major granulocytic phagocytes?
neutrophils
macrophages
Eosinophils are particular helpful for which bugs?
helminths
Half of neutrophils in BM circulate where? and other half ?
plasma
lungs, liver, spleen, endothelium
What bugs are particularly well opsonized by neutrophils?
s pneumo
gas
h influ
staph aureus
Which bacteria does crp opsonize?
one of initial inflamm response PRO
opsonizes s pneumo
Splenectomy or functional asplenia concerning bacrteria
s pneumonia
h influ
n meningitid
canpcytophaga canimorsus
bordetella
Key antibiotics for immunocompromised pt
aminoglycosides
ext sepctrum pen - piptazo
cephalo: cefepime
carbapenem: imi, mero
other: vanco
amphotericin B
acyclovir
Acyclovir dose for a mucocutaneous herpes zoster in an immunocomp pt:
5mg/kg IV q8h or 400mg PO daily
Acyclovir dose for a mild vs seve herpes zoster in an immunocomp pt:
mild: 800mg PO five times daily or 10mg/kg IV q8h
Acyclovir dose for a primary varicella in an immunocomp pt:
10mg/kg IV q8h
What are unique considerations for febrile neutropenia evaluation and management in children?
-IV cath common site - swab all sources
-peripheral culture if possible
-urine culture and urinalysis given ++ common
-cxr only if sx
-initiate monotherapy as soon as culture done - piptazo, penem
-transfer of ped ca pt to hospital with experienced management when available
Solid organ ca pt - often febrile neutropenia?
no
If suspected listeria, how to tx?
ampicillin
If worried about salmonella, tx with which abx?
third gen cephalosporin or FQ
Pt with solid tumors, lymphoma and leukemia are at risk of pneumonia from what sp?
tx with?
legionella
resp FQ or azithromycin
Nocardiosis - what is this?
severe bact infection with weakly acid fast gram +, filamentous rod, branching
MC manifestation nocardiosis?
nodular infiltrates pneumonia
no fever
Tx nocardia?
sulonamides with other agents
What immunocomp pt are at risk for cryptococcus infection?
lymphomas
CLL and CML
HIV
solid organ transplant
db
renal insuff
cirrhosis
MC manifestation of cryptococcus?
meningitis
Meningitis secondary to cryptococcus dx?
crypto angtigen in serum and csf, fungal culture, tissue biopsy
often high opening pressure and can cause obstr hydrocephalus
Which pt are at risk from pneumocystis jirovecii pneumonia?
AIDS
leukemia
lymphoma
solid tumors taking high dose CS
What abx is prophylactic for PJP?
septra
What parasitic infection is the only helminthis organism producing severe infection in pt with deficient cell mediated immunity?
strongyloides
strongyloides - sx
cns, skin
can have wheeze cough dyspnea, hemoptysis, hemorrhagic rash
top 3 viruses causing serious infecton in cancer pt?
varicella zoster
herepes simplex
cmv
What tx can pt with decreasedm cellulular mediated immunity get for influenza?
oseltamivir
Hypogammaglobulinemia is common in which 2 ca?
CLL
MM
What opportunistic infections can mimic cancer spread?
nocardia, toxo in brain
Budd chiari mimic: asperigllus, mucor, rhizopus –> causing thrombus
Renal vein thrombosis: gram neg bacilli
candida - ureter like post obstr uropathy
Pulmonary nodules - histo pneumocystitis, legionella, aspergilus, nocardia
What are diabetes pt incr risk of infection?
defect in imm function, excess substrate for bacteria and fungal growth, vascular insuff - microangiopathy and AS, sensory neuropathy to wound neglect
neutrophils and monocyte impaired
cellular immunity has decr prolif response
Why does etoh use/cirrhosis incr risk of infection?
suppression immune system
altered blood flow
depression mental status
delay in seeking medical care
malnutrition
cig smike
chronic lung disease
complement deficiency secondary to loss of C3 (made by liver)
IgM bactericidal decrease
granulocytopenia and dminished leukocyte mobilization
Spont bacteremia and sepsis infections in pt with cirrhosis: caused by which bugs?
ecoli
K pneumoniae
salmonella
streptococci
vibrio vulnifivus
aeromonas
SBP infections in pt with cirrhosis: caused by which bugs?
ecoli
k pneumoniae
s pneumo
enterococci
etoh pt: PMN count 250 cells/mm3 - tx with?
ceftriaxone or cipro until cultures return
Additionally, patients receiving treatment for SBP have been shown to have increased survival and decreased inci- dence of hepatorenal syndrome when administered albumin 1.5 g/kg at ?d and 1 g/kg on day ? of treatment.
on presentation
d3
Why do pt with renal failure get more infections?
often concomittent diabetes
sites of infection at breaks in skin from vascular access, peritoneal dialysis
uremic pruritis
reduced renal clearance
CKD - general immune hyporesponsiveness: neutrophils slow, CMI imapired, leukopenia common. Humoral imm: lower IgG response, inadequate response to vaccines
Renal failure pt - often assume ? + and tx as such
MRSA
What bugs predominate in perionteal dialysis pt perionitis?
s aures, s epidermidis
strep
gram - bacilli
candida
What bug specifically does asplenia put you at risk for?
s pneumo
Bugs from asplenia (list 6)
s pneumo
H influ
n meningitidis
gram - bacilli: ecoli, pseudomonas
babesia
ehrlichiosis - tick borne
bordetella
Diseases causing functional hyposplenism
sickle cell
ulcerative colitis
celiac
sarcoidosis
amyloidosis
RA
SLE
What finding on blood smear indicates hyposplenism?
howell jolly bodies
For pt with asplenia, may not find a source. What abx should you give?
ceftriaxone at meningitic dosing
vanco if R prevalent to penicillin
What immunizations does an asplenia person need?
pneumococcus
h influ type B
N meningitidis
influenza
Asplenia: rule for children receiving prophylaxis with oral ? or ? up to age of _ and for at least ?-? years after splenectomy
pen or amox
age 5
1-2y
How to steroids effect the immune system?
alter distribution and function of neutrophils, monocytes, lymphocytes
difficulty to mobilize them and neutrophil adherence
inhibit phagocytosis and IC killing (CMI impaired)
complement cannot activate
hyperglycemia also contributes
MC sources of infection when on high dose steroids?
s aureus
streptococci
gram neg bacilli
At what dose of predn does adrenal suppression increase?
> 7.5mg/day
Use of CS increases risk of complications from what abdominal disease?
diverticular
List 5 immunosuppressive drugs other CS?
cyclosporine
tacrolimus
mycophenolate
azathioprine
methotrexate
cyclophosphamide
tumor necrossi factor inhibitors are at incr susecptibility of what kind of infections?
disseminated
- tb, non tb mycoplasma, histo, coccidiodomyocisis
What is mucositis?
Mucositis is a frequent prelude to viridans streptococcal bacte- remia, which can produce sudden onset of acute respiratory distress syndrome, a toxic shock–like syndrome, rash, and pneumonia. Impor- tantly, mucositis predisposes the patient to gram-positive infections, and vancomycin is appropriate in addition to a broad-spectrum gram- negative agent.
