Pathology - Immunology Flashcards
Flashcards (472 cards)
1
Q
What are the three main components of innate immunity?
A
Physical barriers, cells, soluble mediators
2
Q
Which immune system responds rapidly (minutes to hours)?
A
Innate immune system
3
Q
Which immune system produces memory cells?
A
Adaptive immune system
4
Q
What are the primary organs of immune cell production?
A
Bone marrow and thymus
5
Q
What are the secondary lymphoid organs?
A
Spleen, lymph nodes, MALT
6
Q
Which cells are the first responders in inflammation?
A
Neutrophils
7
Q
What is the most abundant innate immune cell?
A
Neutrophils
8
Q
Which cells are important against parasites and allergies?
A
Eosinophils
9
Q
What do basophils and mast cells release?
A
Histamine and inflammatory mediators
10
Q
What are the primary functions of macrophages?
A
Phagocytosis and antigen presentation
11
Q
Which are the most important antigen presenting cells?
A
Dendritic cells
12
Q
How do NK cells recognize normal cells?
A
MHC I expression
13
Q
What happens when NK cells lack MHC I signals?
A
They kill the cell
14
Q
Which cytokine is the main pro-inflammatory mediator from macrophages?
A
TNF-α
15
Q
What does IL-1 from macrophages cause?
A
Fever and inflammation
16
Q
Which cytokine recruits neutrophils?
A
IL-8
17
Q
What activates NK cells and promotes Th1?
A
IL-12
18
Q
Which interferons are important against viruses?
A
IFN-α and IFN-β
19
Q
What is the main anti-inflammatory cytokine?
A
TGF-β
20
Q
How many complement pathways exist?
A
Three pathways
21
Q
What activates the classical complement pathway?
A
IgG/IgM immune complexes
22
Q
What directly activates the alternative pathway?
A
Bacterial cell wall components
23
Q
What does C3b act as?
A
Opsonin for phagocytosis
24
Q
What does C5a cause?
A
Chemotaxis and inflammation
25
What forms the membrane attack complex?
C5b-C9
26
What are the six steps of phagocytosis?
Recruitment, recognition, endocytosis, phagolysosome, killing, death
27
What recognizes pathogen-associated molecular patterns?
Toll-like receptors (TLRs)
28
What are the main opsonins?
IgG, C3b, CRP
29
Which enzyme complex produces reactive oxygen species?
NADPH oxidase
30
What converts hydrogen peroxide to hypochlorous acid?
Myeloperoxidase
31
What are the two main adaptive immunity types?
Humoral and cell-mediated
32
Which cells are involved in humoral immunity?
B cells and antibodies
33
Which cells mediate cell-mediated immunity?
CD4+ and CD8+ T cells
34
What do CD8+ T cells recognize?
MHC Class I molecules
35
What do CD4+ T cells recognize?
MHC Class II molecules
36
Which HLA molecules are MHC Class I?
HLA-A, HLA-B, HLA-C
37
Which HLA molecules are MHC Class II?
HLA-DP, HLA-DQ, HLA-DR
38
Where do T cells mature?
Thymus
39
What is positive selection in the thymus?
Selection for HLA affinity
40
What is negative selection in the thymus?
Elimination of self-reactive cells
41
What do Th1 cells help with?
Cell-mediated immunity
42
What cytokines do Th1 cells produce?
IL-2, IFN-γ, TNF-α
43
What do Th2 cells help with?
Humoral immune response
44
What cytokines do Th2 cells produce?
IL-4, IL-5, IL-6
45
What do Th17 cells help recruit?
Neutrophils
46
What do Treg cells suppress?
Autoimmunity
47
What markers do Treg cells express?
CD25+ and FOXP3+
48
How do CD8+ T cells kill target cells?
Perforin and granzymes
49
What triggers apoptosis in target cells?
Fas ligand expression
50
What are the two types of T cell memory?
Central and effector memory
51
Where are central memory T cells found?
Lymph nodes and spleen
52
Where are effector memory T cells found?
Liver, lungs, gut
53
What do central memory cells express?
CCR7+ and CD62L high
54
What do effector memory cells lack?
CCR7 and CD62L
55
Where do B cells mature?
Bone marrow
56
What is central tolerance for B cells?
Elimination of self-reactive cells
57
What triggers initial IgM production?
B cell receptor binding
58
What is required for class switching?
CD4+ Th2 cell help
59
What signals are needed for B cell activation?
TCR/CD4-MHCII and CD40L-CD40
60
What happens in germinal centers?
Proliferation and class switching
61
What increases antibody diversity?
Somatic hypermutation
62
What improves antibody binding?
Affinity maturation
63
How many heavy and light chains in immunoglobulins?
Two heavy, two light
64
What determines immunoglobulin isotype?
Heavy chain type
65
Where does antigen bind on antibodies?
Fab region
66
What mediates effector functions?
Fc region
67
Which antibody appears first in immune response?
IgM
68
Which antibody is most abundant in serum?
IgG
69
Which antibody crosses the placenta?
IgG
70
Which antibody is in breast milk?
IgA
71
Which antibody is associated with allergies?
IgE
72
What is IgM's structure?
Pentamer
73
What is IgA's structure in secretions?
Dimer
74
Which antibody has greatest avidity?
IgM (10 binding sites)
75
Which antibody has greatest affinity?
IgG
76
What protects against intraluminal pathogens?
Secretory IgA
77
Where is IgE normally located?
Mast cell surfaces
78
What cytokine stimulates all T cells?
IL-2
79
What supports bone marrow stem cells?
IL-3
80
What induces Th2 differentiation?
IL-4
81
What stimulates eosinophils?
IL-5
82
What is the main anti-inflammatory cytokine from Th2?
IL-10
83
What causes fever from IL-1?
Hypothalamic stimulation
84
What defines immune memory?
Enhanced secondary response
85
What test detects TB exposure?
Mantoux test
86
What type of hypersensitivity is Mantoux?
Type IV
87
What indicates positive Mantoux test?
≥10mm induration
88
What is SCID?
Severe combined immunodeficiency
89
What cells are absent in X-linked SCID?
T cells and NK cells
90
What is DiGeorge syndrome caused by?
22q11.2 microdeletion
91
What structures fail to develop in DiGeorge?
Thymus and parathyroids
92
What is Bruton's agammaglobulinemia?
Absent B cells
93
What gene is mutated in Bruton's?
BTK (Bruton tyrosine kinase)
94
What is CVID?
Common variable immunodeficiency
95
What is the most common primary immunodeficiency?
Selective IgA deficiency
96
What causes chronic granulomatous disease?
NADPH oxidase deficiency
97
What infections occur in CGD?
Catalase-positive organisms
98
What test is negative in CGD?
Nitroblue tetrazolium (NBT)
99
What causes leukocyte adhesion deficiency?
CD18 deficiency (Beta-2 integrin subunit)
100
What is absent in LAD?
Pus formation
101
What defines autoinflammatory diseases?
Innate immune system dysfunction
102
What defines autoimmune diseases?
Adaptive immune system dysfunction
103
What is familial Mediterranean fever caused by?
MEFV gene mutation
104
What does pyrin normally regulate?
IL-1 production
105
What is first-line treatment for FMF?
Colchicine
106
What is APS-1 caused by?
AIRE gene mutation
107
What does AIRE regulate?
Central T cell tolerance
108
What is IPEX caused by?
FOXP3 mutation
109
What cells are defective in IPEX?
Regulatory T cells
110
What is ALPS caused by?
Fas pathway mutations
111
What accumulates in ALPS?
Lymphocytes
112
What pattern indicates SLE on ANA?
Homogeneous or peripheral
113
What antibody is most specific for SLE?
Anti-dsDNA
114
What antibody is associated with Sjögren's?
Anti-Ro and Anti-La
115
What antibody indicates limited scleroderma?
Anti-centromere
116
What antibody indicates diffuse scleroderma?
Anti-Scl70
117
What is c-ANCA directed against?
Proteinase 3
118
What disease is associated with c-ANCA?
Granulomatosis with polyangiitis
119
What is p-ANCA directed against?
Myeloperoxidase
120
Which diseases show p-ANCA?
EGPA and microscopic polyangiitis
121
What HLA is associated with ankylosing spondylitis?
HLA-B27
122
What HLA is associated with celiac disease?
HLA-DQ2/DQ8
123
What HLA is associated with rheumatoid arthritis?
HLA-DR1/DR4
124
What HLA is associated with SLE?
HLA-DR2/DR3
125
What defines Type I hypersensitivity?
IgE-mediated immediate reaction
126
What cells degranulate in Type I?
Mast cells and basophils
127
What mediator causes Type I symptoms?
Histamine
128
What is the most severe Type I reaction?
Anaphylaxis
129
What is first-line treatment for anaphylaxis?
IM adrenaline
130
What defines Type II hypersensitivity?
Antibody against cell antigens
131
What test confirms autoimmune hemolysis?
Direct Coombs test
132
What defines Type III hypersensitivity?
Immune complex deposition
133
What complement levels are seen in Type III?
Low C3 and C4
134
What defines Type IV hypersensitivity?
T cell-mediated delayed reaction
135
What is an example of Type IV?
Contact dermatitis
136
What antibody is tested for celiac disease?
Anti-transglutaminase (IgA)
137
What must be checked before celiac testing?
IgA deficiency
138
What biopsy finding confirms celiac?
Villous atrophy
139
What creates active immunity?
Own antibody production
140
What creates passive immunity?
Pre-formed antibody administration
141
How long does passive immunity last?
~3 weeks
142
What are live attenuated vaccines?
Modified live pathogens
143
What are inactivated vaccines?
Killed pathogens or components
144
What are conjugate vaccines?
Polysaccharide plus protein carrier
145
Who cannot receive live vaccines?
Immunocompromised and pregnant
146
What vaccines are in MMR?
Measles, mumps, rubella
147
Who receives BCG vaccine?
High-risk individuals
148
What does BCG protect against?
Tuberculosis
149
How long does BCG protection last?
10-15 years
150
What are depot adjuvants?
Slow antigen release
151
What are stimulatory adjuvants?
Mimic PAMPs
152
What is the most common depot adjuvant?
Alum
153
What is HAART?
Highly active antiretroviral therapy
154
What is standard HAART combination?
2 NRTIs + PI/NNRTI
155
What drug class ends in "-navir"?
Protease inhibitors
156
What drug class has "vir" in middle?
NNRTIs
157
What drug class ends in "-tegr"?
Integrase inhibitors
158
What is first-line immunosuppression post-transplant?
Triple therapy
159
What drugs comprise triple therapy?
Steroid, CNI, antiproliferative
160
What is hyperacute rejection?
Minutes to hours
161
What causes hyperacute rejection?
Preformed antibodies
162
What is acute cellular rejection?
<6 months, CD4+ mediated
163
What is chronic rejection characterized by?
Fibrosis and vasculopathy
164
What is GVHD?
Graft-versus-host disease
165
What organs does GVHD affect?
Skin, gut, liver
166
What prevents GVHD?
HLA matching
167
What treats GVHD?
Corticosteroids
168
What increases post-transplant infection risk?
Immunosuppressive therapy
169
What malignancies increase post-transplant?
Viral-associated and skin cancers
170
What is HIV tropism determined by?
Co-receptor usage (CCR5/CXCR4)
171
What cells does HIV primarily infect?
CD4+ T cells
172
What enzyme converts HIV RNA to DNA?
Reverse transcriptase
173
What CD4 count defines AIDS?
<200 cells/μL
174
What infection occurs at CD4 <150?
Pneumocystis jirovecii
175
What infection occurs at CD4 <50?
MAC (mycobacterium avium complex)
176
What are long-term nonprogressors?
Stable CD4 >10 years
177
What test confirms HIV infection?
Western blot
178
When do HIV antibodies appear?
~10 weeks post-infection
179
What monitoring is done for HIV treatment?
Viral load and CD4
180
What is the goal of HIV treatment?
Undetectable viral load
181
What do corticosteroids inhibit?
Phospholipase A2
182
What do calcineurin inhibitors block?
IL-2 expression
183
What are the main calcineurin inhibitors?
Cyclosporin and tacrolimus
184
What is mycophenolate's mechanism?
Inhibits IMPDH
185
What does azathioprine block?
Purine synthesis
186
What enzyme deficiency affects azathioprine?
TPMT
187
What does rituximab target?
CD20 on B cells
188
What do TNF-α inhibitors treat?
Rheumatoid arthritis, IBD
189
What serious infection risk with TNF-α inhibitors?
Tuberculosis reactivation
190
What virus causes PML?
JC virus
191
What cells does JC virus infect?
Oligodendrocytes
192
What is desensitization therapy?
Gradual allergen exposure
193
What allergies can be desensitized?
Bee venom, grass pollen
194
What cannot be desensitized?
Food and latex
195
What is an isograft?
Transplant from twin
196
What is an allograft?
Same species transplant
197
What is a xenograft?
Different species transplant
198
What is the most commonly transplanted organ?
Kidney
199
What is maximum HLA mismatches?
6
200
What is sibling HLA matching probability?
25% perfect match
201
What causes burn infection susceptibility?
Damaged physical barriers
202
What organisms colonize after antibiotics?
Candida and C. difficile
203
What is Kostmann syndrome?
Severe congenital neutropenia
204
What treats Kostmann syndrome?
G-CSF
205
What is cyclical neutropenia?
Neutropenia every 4-6 weeks
206
What is LAD triad?
Late cord separation, absent pus, dysfunction neutrophilia
207
What organisms cause infections in CGD?
PLACESS organisms
208
What does PLACESS stand for?
Pseudomonas, Listeria, Aspergillus, Candida, E.coli, Staph, Serratia
209
What treats CGD?
Interferon-gamma
210
What causes classical complement deficiency?
C1, C2, C4 deficiency
211
What infections occur with complement deficiency?
Encapsulated bacteria
212
What bacteria commonly cause complement deficiency infections?
Neisseria, Streptococcus, Haemophilus
213
What test assesses classical pathway?
CH50
214
What test assesses alternative pathway?
AP50
215
What is C3 deficiency associated with?
SLE risk
216
What causes terminal complement deficiency?
C5-C9 deficiency
217
What is MBL deficiency?
Mannose-binding lectin deficiency
218
When does MBL deficiency cause problems?
With other comorbidities
219
What is secondary C3 deficiency caused by?
Nephritic factor
220
What accompanies secondary C3 deficiency?
MPGN and lipodystrophy
221
What cells are low in DiGeorge?
T cells
222
What is low in DiGeorge besides T cells?
Calcium (hypoparathyroidism)
223
What is CATCH-22?
DiGeorge syndrome mnemonic
224
What does BLS Type II affect?
MHC Class II expression
225
What is BLS Type II associated with?
Sclerosing cholangitis
226
What cells are absent in Bruton's?
B cells
227
What immunoglobulins are absent in Bruton's?
All classes
228
When do Bruton's infections start?
After 3 months
229
What is contraindicated in Bruton's?
Live vaccines
230
What treats Bruton's agammaglobulinemia?
IVIG every 3 weeks
231
What defines CVID?
Low IgG, normal IgM
232
When is CVID diagnosed?
After puberty
233
What percentage of IgA deficiency is asymptomatic?
Two-thirds
234
What reaction can occur with IgA deficiency?
Transfusion anaphylaxis
235
What is X-linked SCID caused by?
Common gamma chain defect
236
What percentage of SCID is X-linked?
45%
237
What cells are normal in X-linked SCID?
B cells
238
What is ADA deficiency?
Adenosine deaminase deficiency
239
How does ADA SCID differ from X-linked?
Low B cells too
240
What treats ADA deficiency?
PEG-ADA replacement
241
What is hyper-IgM syndrome caused by?
CD40 ligand deficiency
242
What infections occur in hyper-IgM?
Opportunistic infections
243
What is Wiskott-Aldrich caused by?
WASP gene mutation
244
What is WATER mnemonic for?
Wiskott-Aldrich syndrome
245
What blood finding is seen in Wiskott-Aldrich?
Small platelets
246
What is FMF inheritance?
Autosomal recessive
247
What gene is mutated in FMF?
MEFV
248
What protein does MEFV encode?
Pyrin
249
How long do FMF episodes last?
48-96 hours
250
What long-term complication occurs in FMF?
AA amyloidosis
251
What is Crohn's associated gene?
NOD2 (CARD15)
252
What percentage of Crohn's has NOD2 mutations?
30%
253
What triggers autoinflammatory disease in Crohn's?
Intestinal microbiota
254
What is central tolerance failure?
APS-1
255
What is peripheral tolerance failure?
IPEX
256
What is lymphocyte apoptosis failure?
ALPS
257
What causes molecular mimicry?
Cross-reactive antibodies
258
What is an example of molecular mimicry?
Post-strep rheumatic fever
259
What causes hidden antigen exposure?
Tissue damage
260
What is Dressler's syndrome?
Post-MI pericarditis
261
What modifies self-antigens?
Drugs or infections
262
What causes cold AIHA?
Mycoplasma infection
263
What is ANA testing used for?
Autoimmune disease screening
264
What cells are used for ANA testing?
HEp-2 cells
265
What does ANA titre represent?
Dilution until undetectable
266
What pattern suggests SLE?
Homogeneous or peripheral
267
What pattern suggests scleroderma?
Nucleolar or centromere
268
What pattern is nonspecific?
Speckled
269
What does speckled pattern contain?
ENAs (extractable nuclear antigens)
270
What antibody is specific for SLE?
Anti-Smith
271
What antibody correlates with SLE activity?
Anti-dsDNA
272
What antibodies cause neonatal heart block?
Anti-Ro
273
What is CREST syndrome?
Limited systemic sclerosis
274
What does CREST stand for?
Calcinosis, Raynaud's, Esophageal, Sclerodactyly, Telangiectasia
275
What is GPA formerly called?
Wegener's granulomatosis
276
What does GPA affect?
Upper respiratory, lungs, kidneys
URT, LRT, Kidneys
277
What causes saddle-nose deformity?
GPA
278
What is EGPA formerly called?
Churg-Strauss syndrome
279
What accompanies EGPA?
Asthma and eosinophilia
280
What is MPA?
Microscopic polyangiitis
281
What anemia suggests RA?
Anemia of chronic disease
282
What joint deformities occur in RA?
Swan neck, boutonniere
283
What spares the DIP joints?
Rheumatoid arthritis
284
What is SOAP BRAIN MD?
SLE criteria mnemonic
285
What complement pattern indicates active SLE?
Low C4, normal C3
286
What complement pattern indicates severe SLE?
Low C4, low C3
287
What test measures tear production?
Schirmer's test
288
What rash is pathognomonic for dermatomyositis?
Heliotrope rash
289
What are Gottron's papules?
Dermatomyositis skin lesions
290
What malignancy is associated with dermatomyositis?
Ovarian cancer
291
What biopsy pattern shows dermatomyositis?
Perimysial inflammation
292
What biopsy pattern shows polymyositis?
Endomysial inflammation
293
What antibody is common to both myositides?
Anti-Jo1
294
What organ is at risk in limited scleroderma?
Lungs (pulmonary hypertension)
295
What is scleroderma renal crisis?
Acute hypertensive nephropathy
296
What causes Type I diabetes?
Autoimmune beta cell destruction
297
What antibodies are found in Type I diabetes?
Anti-GAD, anti-islet cell
298
What characterizes MS?
CNS demyelination
299
What CSF finding suggests MS?
Oligoclonal IgG bands
300
What treats MS relapses?
Corticosteroids
301
What prevents MS relapses?
Interferon-β
302
What causes contact dermatitis?
Environmental chemicals
303
What type of hypersensitivity is contact dermatitis?
Type IV
304
What test diagnoses contact dermatitis?
Patch test
305
What cells mediate Crohn's inflammation?
Th1 cells
306
What characterizes Crohn's lesions?
Skip lesions
307
What treats Crohn's disease?
Anti-TNF agents
308
What duodenal changes occur in celiac?
Villous atrophy
309
What lymphocytes increase in celiac?
Intraepithelial lymphocytes
310
What skin condition accompanies celiac?
Dermatitis herpetiformis
311
What antibody disappears with gluten-free diet?
Anti-endomysial (EMA)
312
What is the most sensitive celiac antibody?
Anti-transglutaminase
313
What creates active immunity?
Vaccination or natural infection
314
What examples provide passive immunity?
HNIG, HBIG, HRIG
315
What age gets annual influenza vaccine?
50 years onwards
316
What age gets pneumococcal vaccine?
65 years
317
What age gets shingles vaccine?
70 years
318
What vaccines are given in pregnancy?
Influenza and DTaP/IPV
319
What does BCG stand for?
Bacilli Calmette-Guerin
320
What is BCG made from?
Attenuated bovine TB
321
How effective is BCG against primary TB?
19-27%
322
How effective is BCG against progression?
71%
323
What does MMR-VBOY represent?
Live attenuated vaccines
324
What advantage do live vaccines have?
Lifelong immunity possible
325
What disadvantage do live vaccines have?
Reversion to virulence
326
What is VAPP?
Vaccine-associated paralytic polio
327
What do inactivated vaccines require?
Repeated boosters
328
What are conjugate vaccines effective against?
Encapsulated bacteria
329
What does NHS Trust mnemonic represent?
Conjugate vaccines
330
What are mRNA vaccines?
Genetic material vaccines
331
What is the advantage of mRNA vaccines?
Non-infectious, non-integrating
332
What are depot adjuvants' mechanism?
Slow antigen release
333
What are stimulatory adjuvants' mechanism?
Mimic pathogen patterns
334
What is the most common depot adjuvant?
Alum
335
What is the common stimulatory adjuvant?
CpG
336
What is HSCT used for?
Life-threatening immunodeficiency
337
What conditions require HSCT?
SCID, LAD
338
What is autologous HSCT?
Own cells
339
What is allogeneic HSCT?
Donor cells
340
What complications follow HSCT?
GVHD
341
What is IVIg made from?
>1000 donor plasma
342
How often is IVIg given?
Every 3-4 weeks
343
What is IVIg half-life?
18 days
344
What treats renal cell carcinoma?
IL-2
345
What treats hepatitis B and C?
Interferon-alpha
346
What treats CGD?
Interferon-gamma
347
What treats MS?
Interferon-beta
348
What is ipilimumab's target?
CTLA4
349
What is pembrolizumab's target?
PD-1
350
What blocks T cell co-stimulation?
CTLA4
351
What causes T cell exhaustion/death?
PD-1 signaling
352
What are the three T cell signals?
Activation, survival, differentiation
353
What provides T cell activation signal?
MHC-TCR interaction
354
What provides T cell survival signal?
B7-CD28 interaction
355
What provides differentiation signal?
Cytokines
356
What are common steroid side effects?
Diabetes, osteoporosis, infection
357
What causes hemorrhagic cystitis?
Cyclophosphamide
358
What must be checked before azathioprine?
TPMT activity
359
What interacts dangerously with azathioprine?
Allopurinol
360
What causes pulmonary fibrosis?
Methotrexate
361
What is given with methotrexate?
Folic acid
362
What causes gingival hypertrophy?
Cyclosporin
363
What is less nephrotoxic than cyclosporin?
Tacrolimus
364
What inhibits mTOR?
Sirolimus/rapamycin
365
What inhibits JAK1/3?
Tofacitinib
366
What blocks CD25?
Basiliximab
367
What reduces T cell co-stimulation?
Abatacept
368
What depletes B cells?
Rituximab
369
What blocks gut lymphocyte migration?
Vedolizumab
370
What blocks CNS lymphocyte migration?
Natalizumab
371
What is the risk with natalizumab?
BK virus > PML
372
What blocks IL-6 receptor?
Tocilizumab
373
What do TNF-α inhibitors end in?
-mab (except etanercept)
374
What mnemonic represents TNF-α inhibitors?
CAGE
375
What blocks IL-12/23?
Ustekinumab
376
What blocks IL-17?
Secukinumab
377
What blocks RANK ligand?
Denosumab
378
What causes avascular necrosis of jaw?
Denosumab
379
What removes pathogenic antibodies?
Plasmapheresis
380
When is plasmapheresis used?
Severe Type II hypersensitivity
381
What blocks Fc receptors?
IVIG
382
What is desensitization good for?
Bee venom, grass pollen
383
How long does desensitization treatment last?
3-5 years
384
What is the only disease-modifying allergy treatment?
Desensitization
385
Where are transplanted kidneys placed?
Iliac fossa
386
Are recipient kidneys removed in transplant?
No
387
What determines transplant rejection risk?
HLA mismatch
388
Which HLA is most important?
DR > B > A
389
What causes hyperacute rejection?
ABO or HLA antibodies
390
How is hyperacute rejection prevented?
Crossmatching
391
What mediates acute cellular rejection?
CD4+ T cells
392
What treats acute cellular rejection?
Steroids or OKT3
393
What mediates antibody-mediated rejection?
Anti-HLA antibodies
394
What treats antibody-mediated rejection?
Plasmapheresis and anti-CD20
395
What characterizes chronic rejection?
Fibrosis and ischemia
396
What increases chronic rejection risk?
Multiple acute episodes
397
What three assays test crossreactivity?
Cytotoxicity, FACS, Luminex
398
What is triple immunosuppression?
Steroid + CNI + antiproliferative
399
What induces transplant tolerance?
Anti-CD52 or anti-CD25
400
What infections increase post-transplant?
CMV, BK virus, PCP
401
What cancers increase 100-fold post-transplant?
Viral-associated cancers
402
What increases 20-fold post-transplant?
Skin cancer
403
What increases CVD risk post-transplant?
Immunosuppressive drugs
404
What is HIV structure?
RNA retrovirus
405
What surrounds HIV RNA?
Capsid and envelope
406
What proteins mediate HIV attachment?
gp120 and gp41
407
What receptor does HIV bind first?
CD4
408
What co-receptors does HIV use?
CCR5 and CXCR4
409
What converts HIV RNA to DNA?
Reverse transcriptase
410
What integrates HIV DNA into host?
Integrase
411
What packages viral proteins?
Gag protein
412
What are the three HIV disease stages?
Acute, asymptomatic, AIDS
413
What percentage have acute HIV symptoms?
70%
414
What is median time to AIDS?
8-10 years
415
What percentage are rapid progressors?
10%
416
What percentage are long-term nonprogressors?
<5%
417
What CD4 count indicates MAC risk?
<50
418
What CD4 count indicates Pneumocytis jirovecii risk?
<150
419
What CD4 count indicates pulmonary TB risk?
300-350
420
What CD4 count indicates Kaposi's risk?
<400
421
What confirms HIV infection?
Western blot
422
What is the HIV window period?
~10 weeks
423
When is HIV RNA testing used?
Negative serology, high suspicion
424
How is HIV diagnosed in infants?
HIV DNA/RNA testing
425
What indicates AIDS by CD4 count?
<200 cells/μL
426
What measures HIV treatment response?
Viral load
427
What is the goal of HIV treatment?
Undetectable viral load
428
What happens when HIV treatment stops?
Detectable in 2-3 weeks
429
What is standard HIV treatment?
2 NRTIs + third agent
430
What HIV drug is used in pregnancy?
Zidovudine
431
How much does perinatal HIV treatment reduce transmission?
From 26% to 8%
432
What do NRTIs inhibit?
Reverse transcriptase
433
What do NNRTIs inhibit?
Reverse transcriptase (non-competitively)
434
What do protease inhibitors block?
Viral protein processing
435
What do integrase inhibitors block?
HIV DNA integration
436
What do fusion inhibitors block?
Viral entry
437
What side effect is specific to NRTIs?
Mitochondrial toxicity
438
What side effect is specific to NNRTIs?
Rash and hepatitis
439
What side effects occur with protease inhibitors?
Lipodystrophy and diabetes
440
What monitoring is needed on HAART?
Viral load and toxicities
441
What defines treatment failure?
Detectable viral load
442
What causes HIV drug resistance?
Poor adherence
443
How is HIV resistance tested?
Genotypic and phenotypic
444
What limits HAART effectiveness?
Latent HIV reservoirs
445
What doesn't HAART restore?
HIV-specific T cell responses
446
What chronic problems persist on HAART?
Immune inflammation
447
What diseases result from chronic inflammation?
CVD, liver, bone disease
448
What cells does HIV primarily target?
CD4+ T helper cells
449
What happens to HIV-infected CD4 cells?
Killed by CD8+ cells
450
How does HIV evade immunity?
Quasispecies production
451
What enzyme causes HIV genetic diversity?
Error-prone reverse transcriptase
452
What determines HIV disease progression?
Initial viral burden
453
What characterizes HIV infection?
CD4 depletion and immune activation
454
What architecture is disrupted in HIV?
Lymph node architecture
455
What immune response is lost in HIV?
Antigen-specific humoral response
456
What immune cells become exhausted in HIV?
CD4 and CD8 T cells
457
What is required for effective HIV immunity?
Neutralizing antibodies plus CTL
458
What HIV transmission has highest risk?
First 6 months infection
459
What are the main HIV transmission routes?
Sexual, blood, vertical
460
What percentage of HIV is sexually transmitted?
Majority
461
What reduces sexual HIV transmission?
Undetectable viral load
462
What reduces vertical HIV transmission?
Antiretroviral therapy
463
What is HIV post-exposure prophylaxis?
Antiretrovirals within 72 hours
464
How long is HIV PEP given?
28 days
465
What is HIV pre-exposure prophylaxis?
Daily antiretrovirals
466
Who should receive HIV PrEP?
High-risk individuals
467
What maintains HIV latency?
Integrated provirus
468
What would eliminate reactivated HIV?
Enhanced immune responses
469
What is the major HIV reservoir?
Resting CD4+ T cells
470
Where else does HIV persist? apart from T cell
Macrophages, CNS
471
What is needed for HIV cure?
Reservoir elimination
472
What immune responses control HIV?
Strong CD8+ T cell responses
