Path 6b Flashcards

IgG and IgM promote destruction of self-cells through phagocytosis, lysis, or injury. Which hypersensitivity type is this?

A. Type III

B. Type I

C. Type IV

D. Type II

Which hypersensitivity reaction is driven by Th2 cells, IgE, and mast cells?

A. Type I

B. Type II

C. Type III

D. Type IV

Which hypersensitivity reaction is primarily antibody-mediated against self-cells?

A. Type II

B. Type IV

C. Type I

D. Type III

Circulating antigen-antibody complexes deposit in tissues and cause inflammation. Which hypersensitivity type is occurring?

A. Type IV

B. Type III

C. Type II

D. Type I

Which antibodies primarily form pathogenic complexes in type III hypersensitivity?

A. IgA and IgE

B. IgE and IgM

C. IgA and IgG

D. IgG and IgM

T lymphocytes react against self-antigens in which hypersensitivity type?

A. Type I

B. Type II

C. Type IV

D. Type III

Which hypersensitivity reaction is classified as cell-mediated?

A. Type II

B. Type IV

C. Type III

D. Type I

Minutes after allergen exposure, a patient develops vasodilation and vascular leakage. Which phase is occurring?

A. Granulomatous phase

B. Cytotoxic phase

C. Late phase

D. Immediate phase

Which finding is characteristic of immediate type I hypersensitivity?

A. Fibrinoid necrosis

B. Smooth muscle spasms

C. Granuloma formation

D. CTL-mediated apoptosis

The immediate phase of type I hypersensitivity typically develops within:

A. Minutes

B. 2–24 hours

C. Several days

D. Several weeks

A patient develops eosinophilic inflammation 8 hours after allergen exposure. Which phase is occurring?

A. Immediate reaction

B. Cytotoxic reaction

C. Late-phase reaction

D. Immune-complex reaction

When does the late phase of type I hypersensitivity typically occur?

A. Within seconds

B. Within 2–24 hours

C. After several weeks

D. After one month

Which cells infiltrate tissues during late-phase type I hypersensitivity?

A. Neutrophils and eosinophils

B. Erythrocytes and platelets

C. Plasma cells and platelets

D. Fibroblasts and osteoclasts

Which additional leukocytes participate in late-phase type I reactions?

A. NK cells and B cells

B. CTLs and plasma cells

C. Platelets and erythrocytes

D. Basophils and monocytes

Which T-cell subset may also appear during late-phase type I hypersensitivity?

A. CD8+ T cells

B. CD4+ T cells

C. Gamma-delta T cells

D. Regulatory B cells

What is the first cellular event leading to Th2-driven type I hypersensitivity?

A. Mast-cell degranulation

B. Dendritic-cell antigen encounter

C. Immune-complex deposition

D. CTL perforin release

After dendritic-cell antigen presentation, naive T cells differentiate into which cells during allergic sensitization?

A. Th2 cells

B. Th1 cells

C. CTLs

D. NK cells

Which mast-cell receptor binds IgE antibodies?

A. CD16

B. HLA-DR

C. Fc-gamma-RI

D. Fc-epsilon-RI

A mast cell coated with antigen-specific IgE is described as:

A. Sensitized

B. Tolerized

C. Opsonized

D. Anergic

An atopic individual is best described as someone who is:

A. Prone to allergies

B. Resistant to allergies

C. Deficient in antibodies

D. Unable to form granulomas

Which immunoglobulin is increased in individuals prone to atopic reactions?

A. IgA

B. IgM

C. IgG

D. IgE

Atopic individuals characteristically have increased numbers of which cytokine-producing cells?

A. IL-2-producing CTLs

B. IL-1-producing macrophages

C. IL-4-producing Th2 cells

D. IFN-gamma-producing Th1 cells

Which combination best characterizes an atopic individual?

A. IgM and Th1 cells

B. IgE and IL-4 Th2 cells

C. IgA and CTLs

D. IgG and NK cells

Immune complexes deposit in renal glomeruli and cause inflammation. Which manifestation is most likely?

A. Glomerulonephritis

B. Meningitis

C. Pneumonia

D. Dermatitis

Type III hypersensitivity commonly affects which joint-associated tissue pattern?

A. Myositis

B. Neuritis

C. Fibrosis

D. Arthritis

Immune-complex deposition in small blood vessels most directly causes:

A. Glomerulonephritis

B. Arthritis

C. Vasculitis

D. Myositis

Which three sites are particularly affected by type III hypersensitivity?

A. Lung, liver, spleen

B. Kidneys, joints, vessels

C. Brain, heart, skin

D. Muscle, bone, nerves

A renal biopsy from an immune-complex disorder shows smudgy eosinophilic tissue destruction. What is this called?

A. Fibrinoid necrosis

B. Liquefactive necrosis

C. Caseous necrosis

D. Fat necrosis

Which microscopic finding is characteristic of type III immune-complex injury?

A. Granuloma formation

B. Caseating necrosis

C. Fibrinoid necrosis

D. Fat necrosis

How does fibrinoid necrosis appear microscopically in immune-complex injury?

A. Clear vacuolated tissue

B. Smudgy eosinophilic tissue

C. Dark basophilic tissue

D. Calcified concentric tissue

Which cytokine is associated here with activation of CD4+ T cells by APCs?

A. IL-2

B. IL-4

C. IL-17

D. IL-1

Granulomatous inflammation is triggered by activation of which T-helper subset?

A. Th2

B. Th17

C. Th1

D. Tfh

Which cytokine is a major trigger for granulomatous inflammation?

A. IL-4

B. IFN-gamma

C. IL-2

D. IL-17

Which pair drives granulomatous inflammation?

A. Th1 and IFN-gamma

B. Th2 and IL-4

C. Tfh and IL-2

D. Th17 and IL-17

A cytotoxic T lymphocyte attacks a target cell. Which molecules does it secrete to initiate killing?

A. IgG and IgM

B. IL-4 and IL-17

C. CD16 and IgE

D. Perforins and granzymes

In the provided CTL pathway, perforins ultimately permit activation of which molecules?

A. Antibodies

B. Granzymes

C. Integrins

D. Interferons

Activated granzymes promote target-cell death by activating:

A. Caspases

B. Complement

C. Histamine

D. Interferons

Caspase activation during CTL-mediated killing ultimately causes:

A. Necrosis

B. Sensitization

C. Apoptosis

D. Opsonization

Which thymic protein promotes expression of peripheral tissue-restricted self-antigens for deletion of self-reactive T cells?

A. RAG1

B. AIRE

C. CD16

D. NLRP3

A patient with defective thymic deletion of self-reactive T cells has an AIRE mutation. Which disorder is most likely?

A. IPEX syndrome

B. Autoimmune polyendocrinopathy

C. Crohn disease

D. Multiple sclerosis

Autoimmune polyendocrinopathy is a group of rare disorders where the immune system attacks and damages multiple _____-producing glands

Peripheral T-cell activation requires TCR recognition of MHC as the first signal. What provides the second signal?

A. CD28 binding B7

B. CD25 binding IL-2

C. TCR binding CD16

D. HLA binding FOXP3

Which molecule on T cells provides costimulatory signaling during activation?

A. B7

B. CD28

C. CD25

D. HLA

Which molecule on an APC binds CD28?

A. FOXP3

B. CD25

C. B7

D. TCR

B7 costimulatory molecules are expressed primarily on which cells here?

A. Plasma cells

B. Dendritic cells

C. Erythrocytes

D. Neutrophils

Which alternative designation is given for B7?

A. CD25

B. CD28

C. CD80/88

D. CD16

Which transcription factor is associated with suppressive regulatory T-cell function?

A. AIRE

B. FOXP3

C. PTPN22

D. NOD2

A child has immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance. Which protein is mutated?

A. FOXP3

B. AIRE

C. CD25

D. HLA-B27

What syndrome is associated with genetic deficiency of FOXP3?

_____ syndrome

What does the “E” in IPEX represent?

A. Encephalopathy

B. Enteropathy

C. Endocarditis

D. Erythrocytosis

What does the “P” in IPEX represent?

A. Polyendocrinopathy

B. Polyneuropathy

C. Pancytopenia

D. Proteinuria

What does the “I” in IPEX represent?

A. Immunodeficiency

B. Immune dysregulation

C. Inflammation

D. Intolerance

What inheritance pattern is represented in IPEX?

A. Autosomal dominant

B. X-linked

C. Autosomal recessive

D. Mitochondrial

Loss of which cells can impair fetal immune tolerance?

A. CD8+ T cells

B. Foxp3+ regulatory T cells

C. NK cells

D. Plasma cells

Which gene family contributes most strongly to autoimmunity?

A. RAG

B. HLA

C. NOD2

D. FOXP3

Which HLA allele is associated with ankylosing spondylitis?

A. HLA-DR4

B. HLA-B27

C. HLA-DQ2

D. HLA-A3

Which gene is associated with rheumatoid arthritis and type 1 diabetes?

A. NOD2

B. PTPN22

C. AIRE

D. CD25

PTPN22 is associated with which disease pair?

A. RA and type 1 diabetes

B. Crohn and ankylosing spondylitis

C. MS and lupus

D. IPEX and sclerosis

Which gene is associated with Crohn disease?

A. PTPN22

B. NOD2

C. AIRE

D. HLA-B27

Mutations affecting which receptor are associated with multiple sclerosis?

A. IL-2 receptor

B. IL-4 receptor

C. Fc receptor

D. B-cell receptor

The IL-2 receptor associated with MS is also called:

A. CD16

B. CD25

C. CD28

D. CD80

Which receptor pair is associated with MS susceptibility?

A. IL-2R and IL-7R

B. IL-4R and IL-17R

C. CD28 and B7

D. CD16 and CD25

Antinuclear antibodies may recognize which nuclear component?

A. DNA

B. Peptidoglycan

C. Cardiolipin

D. Cell membranes

Which nuclear proteins may be targeted by ANAs?

A. Histones

B. Integrins

C. Perforins

D. Caspases

ANAs can target which RNA-associated structures?

A. Histone proteins

B. Nonhistone proteins

C. Cell-wall proteins

D. Membrane lipids

Which additional nuclear structures can ANAs recognize?

A. Ribosomes

B. Nucleolar antigens

C. Lysosomes

D. Centrosomes

What is the main method for detecting ANAs?

A. Direct ELISA

B. Indirect immunofluorescence

C. Western blot

D. Flow cytometry

Homogeneous ANA staining is associated with which targets?

A. Chromatin and histones

B. RNA and centromeres

C. dsDNA and envelope

D. Phospholipids and cardiolipin

A peripheral ANA staining pattern suggests antibodies against:

A. Histones or RNA

B. dsDNA or nuclear envelope

C. Centromeres or plasmid

D. RNA or centromeres

A speckled ANA pattern reflects antibodies against:

A. DNA

B. Non-DNA nuclear constituents

C. Centromeres

D. Nuclear envelope

A centromeric ANA pattern corresponds to antibodies against:

A. Histones

B. Centromeres

C. dsDNA

D. RNA

A nucleolar ANA pattern reflects antibodies against which target?

A. DNA

B. RNA

C. Histones

D. Cardiolipin

Which ANA pattern is associated with systemic sclerosis?

A. Homogeneous

B. Nucleolar

C. Rim

D. Speckled

A lupus patient has a positive nontreponemal syphilis test without infection. Which antibody explains this?

A. Anti-histone antibody

B. Antiphospholipid antibody

C. Anti-centromere antibody

D. Anti-RNA antibody

Patients with systemic lupus erythematosus often produce antiphospholipid antibodies (such as anticardiolipin antibodies), which can bind to the cardiolipin antigen in the screening test and cause a biological false-_____ result without any real infection.

Lupus-associated false-positive syphilis testing involves antibodies against which complex?

A. DNA-histone complex

B. Phospholipid–beta2-glycoprotein complex

C. RNA-protein complex

D. MHC-TCR complex

These lupus antibodies cross-react with which syphilis-test antigen?

A. Cardiolipin

B. Histone

C. Centromere

D. Nucleolin

What is the most common severe lupus nephritis class?

A. Class I

B. Class II

C. Class III

D. Class IV

Class IV lupus nephritis is also called:

A. Minimal mesangial nephritis

B. Diffuse proliferative glomerulonephritis

C. Membranous nephropathy

D. Focal proliferative nephritis

A patient with systemic sclerosis develops tight, hardened fingers that assume a claw-like appearance. Which finding is this?

A. Synovitis

B. Sclerodactyly

C. Myofiber degeneration

D. Cutaneous ulceration

Which skin finding is especially characteristic of systemic sclerosis?

A. Cutaneous fibrosis

B. Synovial inflammation

C. Muscle necrosis

D. Esophageal dysmotility

Cutaneous fibrosis helps distinguish systemic sclerosis from which group?

A. RA, SLE, polymyositis

B. Crohn, UC, celiac

C. MS, ALS, MG

D. Asthma, COPD, bronchiectasis

A patient with systemic sclerosis develops painful skin breakdown. Which manifestation is most likely?

A. Petechiae

B. Ulcerations

C. Vesicles

D. Urticaria

Which gastrointestinal organ is mainly affected by systemic sclerosis?

A. Stomach

B. Colon

C. Esophagus

D. Pancreas

Esophageal involvement in systemic sclerosis most commonly produces which symptom?

A. Dysphagia

B. Diarrhea

C. Hematemesis

D. Constipation

Which musculoskeletal manifestation can occur in systemic sclerosis?

A. Synovitis

B. Osteomyelitis

C. Tendon rupture

D. Gout

Systemic sclerosis may directly cause degeneration of which structure?

A. Cartilage

B. Myofibers

C. Tendons

D. Ligaments

Which renal complication is associated with systemic sclerosis?

A. Nephrolithiasis

B. Renal failure

C. Cystitis

D. Hydronephrosis

Which manifestation occurs in systemic sclerosis?

A. Pulmonary hypertension

B. Pleural infection

C. Bronchiectasis

D. Pneumothorax

Which additional pulmonary manifestation occurs in systemic sclerosis?

A. Emphysema

B. Fibrosis

C. Atelectasis

D. Abscess

Which cardiac manifestation may occur in systemic sclerosis?

A. Cardiomyopathy

B. Pericardial tamponade

C. Endocarditis

D. Aortic dissection

A systemic sclerosis patient develops an abnormal cardiac rhythm. Which complication does this represent?

A. Myocarditis

B. Arrhythmia

C. Endocarditis

D. Valvulitis

Which six organ systems are prominently affected by systemic sclerosis?

A. Skin, GI, MSK, renal, lung, heart

B. Skin, CNS, liver, spleen, eye, bone

C. GI, CNS, marrow, thyroid, eye, pancreas

D. Renal, liver, marrow, brain, bone, spleen

The major antigenic differences between transplant donor and recipient involve which molecules?

A. HLA alleles

B. IgG subclasses

C. TCR chains

D. Complement proteins

A kidney is transplanted between two genetically different humans. What type of graft is this?

A. Xenograft

B. Allograft

C. Autograft

D. Isograft

A heart valve is transplanted from another species. What type of graft is this?

A. Allograft

B. Autograft

C. Xenograft

D. Isograft

Direct allograft recognition activates which individual's immune cells?

A. Donor T cells

B. Recipient T cells

C. Donor B cells

D. Recipient neutrophils

In indirect allograft recognition, antigen presentation is performed by whose APCs?

A. Donor APCs

B. Recipient APCs

C. Donor neutrophils

D. Recipient platelets

Is this indirect or direct allograft recognition?

Host APCs enter the graft, swallow shed donor proteins, chop them into pieces, and show them via self-MHC.

Is this indirect or direct allograft recognition?

Recipient T cells bind to intact foreign MHC class I or II proteins on the surface of donor cells.

Which sequence correctly orders transplant rejection stages?

A. Acute→hyperacute→chronic

B. Chronic→acute→hyperacute

C. Hyperacute→acute→chronic

D. Hyperacute→chronic→acute

Acute cellular kidney rejection with inflamed tubules is classified as which pattern?

A. Vascular type II

B. Tubulointerstitial type I

C. Hyperacute pattern

D. Chronic fibrotic pattern

Which finding defines tubulointerstitial acute kidney rejection?

A. Inflamed tubules

B. Endotheliitis

C. Glomerular sclerosis

D. Arterial thrombosis

Acute cellular kidney rejection characterized by endotheliitis is which pattern?

A. Tubulointerstitial type I

B. Vascular type II

C. Chronic type III

D. Hyperacute type IV

What histologic process characterizes vascular acute cellular rejection?

A. Endotheliitis

B. Tubulitis

C. Glomerulosclerosis

D. Amyloid deposition

Which transplant immunosuppressant primarily reduces inflammation?

A. Tacrolimus

B. Steroids

C. Mycophenolate mofetil

D. Cilastatin

Which transplant drug inhibits lymphocyte proliferation?

A. Steroids

B. Tacrolimus

C. Mycophenolate mofetil

D. Vancomycin

Which transplant immunosuppressant inhibits Nuclear Factor of Activated T cells (NFAT)?

A. Mycophenolate mofetil

B. Tacrolimus

C. Steroids

D. Cefepime

Nuclear Factor of Activated T cells (NFAT) normally promotes production of which cytokine?

A. IL-1

B. IL-2

C. IL-4

D. IL-17

Tacrolimus suppresses immunity primarily by reducing which cellular function?

A. Bacterial killing

B. T-cell function

C. Neutrophil migration

D. Antibody binding

Which combination represents the three main transplant immunosuppressants listed?

A. Steroids, mycophenolate, tacrolimus

B. Steroids, vancomycin, aztreonam

C. Tacrolimus, cefepime, gentamicin

D. Mycophenolate, daptomycin, penicillin

What is the most frequent infectious complication of immunosuppressive therapy listed here?

A. Polyoma virus

B. Influenza virus

C. Adenovirus

D. Rotavirus

Which viruses are members of the polyoma virus group described here?

A. JCV and BKV

B. HSV and VZV

C. EBV and CMV

D. HBV and HCV

JC virus (JCV) and BK virus (BKV) are the classic human members of the polyomavirus family (Polyomaviridae), known for causing conditions like progressive multifocal leukoencephalopathy and nephropathy in ______ people.

Polyoma viruses associated with transplantation primarily infect which cells?

A. Renal tubules

B. Hepatocytes

C. Alveolar cells

D. Cardiomyocytes

Polyoma virus infection in a transplant recipient can ultimately cause:

A. Graft failure

B. Acute pancreatitis

C. Pulmonary fibrosis

D. Myocardial rupture

One week after stem-cell transplantation, a patient develops rash, jaundice, RUQ pain, and ulcers. What is the diagnosis?

A. Acute GVHD

B. Chronic rejection

C. Hyperacute rejection

D. Polyoma infection

Which timing best supports acute GVHD in this vignette?

A. One week

B. Six months

C. Two years

D. Ten years

A stem-cell recipient develops RUQ pain and jaundice from bile-duct involvement. Which complication best explains this?

A. Acute GVHD

B. Acute kidney rejection

C. Polyoma nephropathy

D. Systemic sclerosis

Which cluster is most consistent with acute GVHD after HSC transplantation?

A. Rash, jaundice, ulcers

B. Dysphagia, fibrosis, synovitis

C. Hematuria, edema, hypertension

D. Cough, fever, hemoptysis

A hematopoietic stem-cell recipient develops skin appendage destruction, dysphagia, RUQ pain, and recurrent infections months later. What is the diagnosis?

A. Acute GVHD

B. Chronic GVHD

C. Humoral rejection

D. Hyperacute rejection

Which timing most strongly supports chronic GVHD after hematopoietic stem-cell transplantation?

A. Within minutes

B. Within hours

C. After few months

D. After one week

A patient develops RUQ pain from liver involvement months after HSC transplantation. What complication is most likely?

A. Acute GVHD

B. Chronic GVHD

C. Hyperacute rejection

D. Polyoma infection

What strategy can prevent graft-versus-host disease before transplantation?

A. Deplete donor T cells

B. Deplete recipient B cells

C. Increase donor neutrophils

D. Increase recipient antibodies

Why are donor T cells depleted before HSC transplantation?

A. Prevent GVHD

B. Prevent lupus

C. Prevent Sjögren syndrome

D. Prevent scleroderma

Which medication can cause drug-induced lupus?

A. Hydralazine

B. Cefazolin

C. Gentamicin

D. Vancomycin

Which antiarrhythmic can cause drug-induced lupus?

A. Procainamide

B. Amiodarone

C. Adenosine

D. Lidocaine

Which antimicrobial can cause drug-induced lupus?

A. Isoniazid

B. Ceftriaxone

C. Aztreonam

D. Daptomycin

Which drug is associated with drug-induced lupus?

A. D-penicillamine

B. Tacrolimus

C. Mycophenolate

D. Cefepime

Which biologic drug class can cause drug-induced lupus?

A. Anti-TNF drugs

B. Anti-IgE drugs

C. Anti-IL-2 drugs

D. Anti-CD16 drugs

Which antibody is associated with drug-induced lupus?

A. Anti-histone

B. Anti-centromere

C. Anti-Scl-70

D. Anti-SS-B

A patient taking procainamide develops lupus-like symptoms. Which antibody is most expected?

A. Anti-histone

B. Anti-centromere

C. Anti-SS-A

D. Anti-U1 RNP

Which autoimmune diseases are commonly associated with Sjögren syndrome?

______

______ ______

______ ______

Sjögren syndrome causes dry eyes through destruction of which glands?

A. Lacrimal glands

B. Thyroid glands

C. Adrenal glands

D. Pituitary glands

Sjögren syndrome causes xerostomia through destruction of which glands?

A. Sebaceous glands

B. Salivary glands

C. Sweat glands

D. Parathyroid glands

What term describes dry eyes in Sjögren syndrome?

A. Xerostomia

B. Keratoconjunctivitis sicca

C. Sclerodactyly

D. Telangiectasia

What term describes dry mouth in Sjögren syndrome?

A. Xerostomia

B. Dysphagia

C. Sclerodactyly

D. Calcinosis

Which mechanism causes sicca symptoms in Sjögren syndrome?

A. Immune-mediated gland destruction

B. Microvascular thrombosis

C. Fibrotic skin injury

D. Donor T-cell attack

Many Sjögren patients have which antibody despite lacking rheumatoid arthritis?

A. Rheumatoid factor

B. Anti-histone

C. Anti-centromere

D. Anti-Scl-70

Which ANA is commonly present in Sjögren syndrome?

A. Anti-SS-A

B. Anti-Scl-70

C. Anti-histone

D. Anti-centromere

Which additional ANA is associated with Sjögren syndrome?

A. Anti-SS-B

B. Anti-DNA

C. Anti-cardiolipin

D. Anti-topoisomerase

SS-A and SS-B antibodies target which general antigen class?

A. Ribonucleoproteins

B. Phospholipids

C. Histones

D. Centromeres

Which antibody is highly specific for diffuse scleroderma?

A. Anti-Scl-70

B. Anti-centromere

C. Anti-histone

D. Anti-SS-A

Anti-Scl-70 antibodies target which enzyme?

A. DNA topoisomerase I

B. RNA polymerase II

C. DNA gyrase

D. Caspase-1

Which antibody is associated with diffuse scleroderma and pulmonary fibrosis?

A. Anti-Scl-70

B. Anti-centromere

C. Anti-SS-B

D. Anti-histone

Which antibody is more common in limited scleroderma?

A. Anti-centromere

B. Anti-Scl-70

C. Anti-histone

D. Anti-U1 RNP

CREST syndrome is most strongly associated with which antibody?

A. Anti-centromere

B. Anti-Scl-70

C. Anti-SS-A

D. Anti-histone

Which manifestation represents the “C” in CREST?

A. Calcinosis

B. Cardiomyopathy

C. Colitis

D. Cystitis

Which manifestation represents the “R” in CREST?

A. Raynaud phenomenon

B. Renal failure

C. Rheumatoid arthritis

D. Rash

Which manifestation represents the “E” in CREST?

A. Esophageal dysmotility

B. Endocarditis

C. Enteropathy

D. Encephalopathy

Which manifestation represents the “S” in CREST?

A. Sclerodactyly

B. Synovitis

C. Sicca syndrome

D. Sepsis

Which manifestation represents the “T” in CREST?

A. Telangiectasia

B. Thrombosis

C. Tubulitis

D. Tenosynovitis

Limited systemic sclerosis may progress to which syndrome?

A. CREST syndrome

B. IPEX syndrome

C. Sjögren syndrome

D. GVHD

What vascular abnormality is the hallmark injury of systemic sclerosis?

A. Microvascular injury

B. Large-vessel thrombosis

C. Venous obstruction

D. Arterial aneurysm

A patient with overlapping connective-tissue disease has high antibody titers against U1 ribonucleoprotein. What diagnosis is suggested?

A. Mixed connective tissue disease

B. Drug-induced lupus

C. Sjögren syndrome

D. Diffuse scleroderma

Which antibody characterizes mixed connective tissue disease?

A. Anti-U1 RNP

B. Anti-histone

C. Anti-centromere

D. Anti-Scl-70

A transplant biopsy shows complement deposition within vascular beds. Which rejection mechanism is supported?

A. Humoral rejection

B. Acute GVHD

C. Cellular rejection

D. Chronic GVHD

Which complement component is used diagnostically for humoral rejection?

A. C4d

B. C3b

C. C5a

D. C1q

Where is C4d deposition detected in humoral transplant rejection?

A. Vascular beds

B. Renal tubules

C. Skin appendages

D. Esophageal mucosa