Diseases of the Immune System Flashcards
Caused by activation of TH2 CD4 helper T cells by environmental antigens —> PRODUCTION OF IgE ANTIBODIES which become attached to mast cells
anaphylaxis
bronchial asthma
allergic rhinitis
sinusitis (hay fever)
food allergies
Type I (immediate, IgE-mediated)
vascular dilation
edema
smooth muscle contraction
mucus production
tissue injury and inflammation
caused by ANTIBODIES that bind to fixed tissues and cell antigens and promote phagocytosis and destruction of the coated cells or trigger pathologic inflammation in tissues
AIHA
Immune Thrombocytopenic Purpura
Pemphigus Vulgaris
ANCA-vasculitis
Goodpasture syndrome
Acute Rheumatic Fever
Myasthenia Graves
Insulin Resistant Diabetes
Pernicious anemia
Type II (Antibody-mediated)
phagocytosis and lysis of cells
inflammation
functional derangements w/o evidence of cell or tissue injury
Caused by ANTIBODIES BINDING ANTIGENS TO FORM COMPLEXES that circulate and may deposit in vascular beds and stimulate inflammation secondary to complement activation
SLE
PSAGN
Polyarteritis Nodosa
Reactive arthritis
Serum sickness
Arthus reaction
Type III (Immune Complex Mediated)
inflammation
necrotizing vasculitis (fibrinoid necrosis)
Cell mediated responses in which T LYMPHOCYTES CAUSE TISSUE INJURY either by producing cytokines that induce inflammation and activate macrophages or by directly killing cells
Rheumatoid arthritis
Multiple sclerosis
Type I DM
IBD
Psoriasis
Contact sensitivity
PPD
Type IV (T cell mediated/delayed)
perivascular cellular infiltrates
edema
granuloma formation
cell destruction
32/F w/ DOB, bilateral elbow joint pains and rash after sun exposure. CBC showed low hemoglobin and reticulocytosis. (+) ANA titer. Diagnosis
Systemic Lupus Erythematosus (SLE)
Mechanisms of organ damage in SLE
Type III
Type II (opsonization and phagocytosis, hematologic manifestations)
MC autoantibody in SLE
ANA
MOST SPECIFIC autoantibodies for SLE
anti-Sm (Smith)
anti-dsDNA - correlates w/ disease activity
Histopathologic findings in SLE w/ skin involvement
LM: liquefactive degeneration of basal layer
edema of DEJ
mononuclear infiltrates around blood vessels and skin apppendages
IF: deposition of IG and complement at DEJ
Type of LE associated w/ HYDRALAZINE, INH, POCAINAMIDE and D-PENICILLAMINE intake, rarely associated w/ anti-dsDNA
Associated w/ ANTI-HISTONE antibodies
Drug-Induced Lupus
34/F, w/ DRY EYES and DRY MOUTH. Lip biopsy shows ACINAR ATROPHY, FIBROSIS and HYALINIZATION of the minor salivary glands
Diagnosis
Sjogren syndrome (late)
MC and most important autoantibody detected in Sjogren syndrome
Anti-Ro (SS-A)
Anti-La (SS-B)
45/F with CHRONIC GERD, hx of PROGRESSIVE DYSPNEA and CKD with noted THICKENING OF THE SKIN
Diagnosis
Systemic Sclerosis(Scleroderma)
MC autoantibody associated w/ DIFFUSE CUTANEOUS SYSTEMIC SCLEROSIS
anti-DNA topoisomerase I (anti-Scl 70)
Common autoantibody associated w/ LIMITED SCLERODERMA (limited cutaneous systemic sclerosis)
Anti-centromere antibodies
48/M, s/p kidney transplant suddenly developed BLOODY URINE few hrs after the procedure. Nephrectomy revealed a CYANOTIC, MOTTLED and FLACCID KIDNEY w/ NECROTIC CORTEX. Biopsy shows THROMBOTIC OCCLUSION OF THE CAPILLARIES and FIBRINOID NECROSIS OF ARTERIAL WALLS.
Diagnosis
Hyperacute Rejection
45/F w/ signs of RENAL FAILURE 2 mos AFTER her RENAL TRANSLANT. Biopsy shows EXTENSIVE INTERSTITIAL MONONCULEAR INFILTRATE w/ edema and mild interstitial hemorrhage.
(+) CD3, CD4 and CD8
Acute cellular (T cell mediated) rejection, Tubuloinerstitial type (tubulitis)
30/M, developed OLIGURIA and SUBSEQUENT RENAL FAILURE 3 WEEKS AFTER an un uneventful kidney transplant. Biopsy shows INFLAMMATION OF GLOMERULI and PERITUBULAR CAPILLARIESw/ FOCAL THROMBOSIS OF SMALL VESSELS.
Diagnosis
Acute Antibody-mediated Rejection
24/F, diagnosed w/ renal failure underwent renal transplant. 4 years later, INCREASING LEVEL OF CREATININE was noted. Biopsy. shows INTERSTITIAL FIBROSIS and TUBULAR ATROPHY.
Diagnosis
Chronic Rejection
66/M, known case of MULTIPLE MYELOMA underwent HSC transplantation presented w/ BLOODY DIARRHEA and GENERALIZED MORBILIFORM RASH FEW WEAKS after the procedure.
Diagnosis
Acute graft VS host disease (GVHD)
Few years after HSC transplantation developd cutaneous sclerosis, jaundice and dysphagia. Barium swallow showed ESOPHAGEAL STRICTURES.
Diagnosis
Chronic GVHD
6 mos/M, w/ MORBILIFORM RASH, RECURRENT ORAL THRUSH, DIAPER RASH and FAILURE TO THRIVE.
PE: (-) CERVICAL LYMPHADENOPATHY
CXR: (-) thymic shadow
Diagnosis
Severe Combined Immunodeficiency (SCID)
7 mos/M, w/ UNREMARKABLE 1st 6 MOS of LIFE, RECURRENT PNEUMONIA and STEATORRHEIC DIARRHEA.
Sputum Culture: H. influenzae
Fecalysis: Giardia lamblia trophozoites
PE: (-) cervical lymphadenopathy
LOW serum Igs
X-Linked Agammaglobulinemia ( Bruton disease)
4 mos/ M, CYANOSIS since BIRTH associated w/ COARSE FACIAL FEATURES and CLEFT PALATE presented w/ RECURRENT VIRAL INFECTIONS.
PE: +3 reflexes
CXR: boot shaped heart (-) thymic shadow
FISH: (+) deletion of Ch22q11.2 locus
Diagnosis
DiGeorge syndrome
8 mos/M, history of ECZEMATOUS DERMATITIS and RECURRENT INFECTIONS.
CBC: low platelet
Diagnosis
Wiskott-Aldrich Syndrome (x-liked recessive)
16/F, with HISTORY OF VIRAL URTI 3 weeks prior, developed RECURRENT UTI and AGE.
Low serum IgA
Diagnosis
Isolated IgA deficiency (acquired)
MC secondary immunodeficiency caused by HIV infection
PROFOUND IMMUNE DEFICIENCY - HALLMARK
Opportunistic infections, secondary neoplasms and neurologic manifesations
CD4 T cells
Acquired Immune Deficiency Syndrome (AIDS)
MC fungal infection in patients w/ AIDS
Candidiasis
MC type of lymphoma associated w/ HIV infection
B-cell lymphoma
AIDS-DEFINING SARCOMA caused by Human Herpesvirus 8 (HHV8)
Typified by appearance of PURPLE PATCHES, PLAQUES or NODULES on the SKIN
Kaposi Sarcoma
Common Autoimmune Diseases and HLA types involved
HLA-B27 - ankylosing spondylitis and RA
HLA-DR,DQ - type I DM and multiple sclerosis
HLA-DQ2, DQ8 - Celiac disease
HLA-DR4 - RA
HLA-DQ - SLE
TRIAD of Sjogren Syndrome
dry eyes (keratoconjunctivitis sicca)
dry mouth (xerostomia)
autoimmune mediated destruction of lacrimal gland and salivary glands
MC associated autoimmune disease in Sjogren syndrome
Rheumatoid Arthritis
TRIAD of Systemic Sclerosis (Scleroderma)
chronic inflammation (autoimmunity)
widespread damage to small blood vessels
progressive interstitial and perivascular fibrosis in the skin and multiple organs
CREST SYNDROME
Calcinosis
Raynaud phenomenon
Esophageal dysmotility
Sclerodactyly
Telangiectasia
Autoantibodies in scleroderma associated with HIGHER risk for pulmonary fibrosis and peripheral vascular disease
Anti-Scl 70 (anti-DNA topoisomerase I)
Defect in migration and chemotaxis of phagocytes
LATE SEPARATION OF UMBILICAL CORD
recurrent skin and mucosal bacterial infection
ABSENT PUS
Leukocyte Adhesion Deficiency (LAD)
AR
defect expression of INTEGRIN
CD18
Defect in migration and chemotaxis of phagocytes
LATE SEPARATION OF UMBILICAL CORD
recurrent skin and mucosal bacterial infection
ABSENT PUS
Leukocyte Adhesion Deficiency (LAD)
AR
defect expression of INTEGRIN
CD18
Defect in LYST gene – problem in PHAGOLYSOSOME FUNCTIONING
ALBINISM
neurodegeneration
recurrent pyogenic infections
CHEDIAK HIGASHI SYNDROME
AR
Defect in MICROBICIDAL activity
Deficiency of NADPH OXIDASE
Severe, persistent and chronic pyogenic infections caused by catalase POSITIVE bacteria
Chronic Granulomatous Disease
XR
Primary Immunodeficiency (Genetic Defects)
INNATE IMMUNITY (Granulocytes)
Leukocyte Adhesion Deficiency (LAD)
CHEDIAK HIGASHI SYNDROME
Chronic Granulomatous Disease
Primary Immunodeficiency (Genetic Defects)
ADAPTIVE IMMUNITY (Lymphocytes)
SCID
X-linked (Bruton) Agammaglobulinemia
Thymic aplasia (CATCH 22)
Absent or markedly decreased B cells in circulation, depressed serum Ig levels (ALL CLASSES)
ABSENT PLASMA CELLS
RECURRENT BACTERIAL AND ENTEROVIRAL INFECTIONS AFTER 6 mos
X-linked (Bruton) Agammaglobulinemia
XR
underdeveloped germinal centers of lymph nodes, Peyer patches, appendix and tonsils
Defective IL-2 receptor gamma chain
ADENOSINE DEAMINASE DEFICIENCY
SMALL THYMUS (-) lymphoid cells
HYPOPLASTIC lymphoid tissues
failure to thrive, chronic diarrhea, thrush
SEVERE COMBINED IMMUNODEFICIENCY (SCID)
22q11 microdeletion
failure to develop 3rd and 4th pharyngeal pouches
ABSENT THYMUS (no thymic shadow on CXR)
ABSENT PARATHYROID GLANDS
LOW T cells in blood and lymphoid tissues
Thymic aplasia (CATCH 22)
CATCH
Cardiac defects (conotruncal abnormalities)
Abnormal facies
Thymic hypoplasia
Cleft palate
Hypocalcemia d.t. parathyroid aplasia
Triad of Wiskott Aldrich Syndrome
WAS gene mutation –> combined B and T cell disorder
associated with SMALL PLATELETS
Thrombocytopenia
Infection
Eczema
MC secondary immunodeficiency
AIDS
Hallmark of AIDS
Profound immune deficiency
Most abundant viral antigen and is widely used to diagnose HIV
protein p24
ATTACHES to CD4 – conformation change – new recognition site of CXCR4 and CCR5 – gp120 binds to CXCR4 and CCR5
gp120
FUSION PROTEIN – integrates itself into host cell membrane – facilitates fusion and delivery of viral genome
gp41
Acute retroviral syndrome
flu-like illness
rash
cervical adenopathy
diarrhea
vomiting
Phase of CLINICAL LATENCY - few or no clinical manifestations
Slow but steady decline in CD4+T cell counts
Increasing viral load
CHRONIC PHASE (AIDS)
7-10 yrs
Dramatic increase in viral load
Opportunistic infections, secondary neoplasms, CNS disease
AIDS
typical phase length (from onset to death) - 2-3 years
MC and most serious form of organ involvement in amyloidosis
KIDNEY
Major organ involved in senile systemic amyloidosis
HEART
