Immune, rhum, allergic disorders

Leukopoiesis

Formation of leukocytes from hematopoietic stem cells in bone marrow

First line of defense

Skin and mucous membrane barriers

Second line of defense

Innate immune response with leukocytes, NK cells, inflammation, and fever

Third line of defense

Adaptive immunity with memory and specific pathogen defense

Innate immunity

Rapid response without memory, non specific, fast 

Adaptive immunity

Slower response with immunologic memory, specific, fast

Natural killer cells (NK cells)

Innate lymphocytes that attack and destroy without specificity 

what do NK cell do

Release cytokines to enhance immune signaling

B cells

Adaptive lymphocytes (plasa cells) that mature in bone marrow and produce antibodies

T cells

Mature in Thymus, include cytotoxic, helper, regulatory, and memory subtypes

Neutrophils

Short-lived WBCs that fight bacteria via phagocytosis and degranulation

What does high neutrophil count suggst?

Bacterial infection

Absolute neutrophil count (ANC)

Measures circulating neutrophils to assess infection risk

Moderate neutropenia

ANC 1000-500

Severe neutropenia

ANC <500

Eosinophils

worms, wheezes, weird diseases

Basophils

Release histamine, heparin, and leukotrienes in allergic responses

Mast cells

Tissue-resident cells releasing histamine, cytokines, and heparin to recruit leukocytes (B/T cells)

Macrophages

Detect and destroy damged tissues.

Complement system

30+ liver-produced proteins aiding innate and adaptive immunity

How do B cells work?

Recognize, react, and remember pathogens via antibody production

How do T cell work

They kill things, and remeber incase it happens again (they hold a grudge)

Primary immune response

First exposure

IgM then IgG

Secondary immune response

Memory B cells rapidly produce IgG

Artificial active immunity

Vaccine-induced antibody formation

Natural passive immunity

Antibodies transferred from mother to infant

Artificial passive immunity

Injection of antibodies (e.g., IVIG)

Cytotoxic T cell actions

Release perforin, interferons, and TNF to kill target cells

Memory T cells

Long-living. Remeber how to kill certain foerign invaders

Type I hypersensitivity

IgE-mediated, immediate reaction (allergy, asthma, anaphylaxis)

Type II hypersensitivity

IgG/IgM attack host cells (cytotoxic autoimmune), blood transusion reaction

Type III hypersensitivity

Immune complex deposition (SLE, PSGN, serum sickness)

Type IV hypersensitivity

Delayed T-cell-mediated (poison ivy, TB test, Hashimoto

s)

Anaphylaxis mechanism

IgE-dependent reaction from mast cells and basophils

Anaphylaxis onset

Within 30 minutes of exposure

Anaphylaxis symptoms

Urticaria, hypotension, bronchospasm, GI upset

Anaphylaxis labs

Elevated tryptase and histamine

Anaphylaxis treatment

Epinephrine 0.5 mg IM q5 min

3, airway, fluids, steroids, antihistamines

Angioedema causes

Allergic vs bradykinin-mediated (ACE inhibitors)

Bradykinin-mediated angioedema

EPI—>Poor response to epi; treat with TXA or bradykinin blockers

Urticaria patho/ treatment

Vascular skin reaction from allergy or infection; treat with antihistamines

Drug-induced cytopenia reaction type and cause

Type II; IgG + complement; caused by penicillin, sulfa, etc.

Drug-induced interstitial nephritis reaction type and leukocyte evolved, how to dianose?

Type IV; AKI with eosinophilia; biopsy diagnostic

what is this patho/treatment

Maculopathic rash -Benign T-cell drug reaction, antihistamine/ topical steroids

Drug Reaction Eosinophilia and Systemic Syndrome Symptoms(DRESS)

Fever, rash, eosinophilia, organ involvement; needs steroids

DRESS cause/ treatment 

cause: meds, mostly abx. treatment: steroids, stop drug

AGEP

AGEP -Pustules, neutrophilia; stop offending drug

SJS/TEN patho /treat

Mucosal sloughing, epidermal necrosis; supportive (burn unit)

AERD -Aspirin-Exacerbated Respiratory Disease causes

COX-1 inhibition → leukotrienes ↑ → asthma, nasal polyps → aspirin desensitization.  

Red man syndrome patho/treat

Non-IgE mast cell activation from vancomycin infusion; avoid trigger, antihistamine 

Osteoarthritis (OA)

Degenerative, non-inflammatory arthritis; pain

with activity

OA imaging

Joint-space narrowing

OA treatment

NSAIDs, acetaminophen, steroid injections, arthroplasty

Does the degree of degerneation correlate with symptoms for oesteo arthrits?

No

Gout, definition and most common areas

Urate crystal build up in serum and deposit in joints—>arthritis and nodular joints AKA tophie ; MTP joint 

Gout treatment

NSAIDs, allopurinal, colchicine (acute treatment 1.2 mg load and 0.6 mg BID), steroids if refractory, diet 

Chronic gout prevention

Allopurinol or febuxostat; avoid thiazides/alcohol

Calcium pyrophosphate Deposition (pseudogout)

Calcium pyrophosphate deposition; chondrocalcinosis on XR.

Gout vs Pseduo gout

Gout is uric crystals, use allopuinol and colchicine, steroids, NSADIS

Pseudo gout it calcium crystals. Colchicine kinda effective, NSAIDS

CPPD / pseudo gout treatment

NSAIDs; colchicine prophylaxis

Seronegative Spondyloarthropathies

Catch all group for Rh negative arthritis types like ankylosing spondylitis and psoriatic arthritis.

Ankylosing spondylitis definition and s/s

Chronic inflammatory disease, High ESR. Rhumatoid factor neg

Young men, chronic back pain, uveitis,bamboo spine on XR

Ankylosing spondylitis treatment

NSAIDs

TNF inhibitors

Psoriatic arthritis def, S/s, Labs 

Chronic autoimmune artithirts that comes from skin psorisis.

S/S: psoriasis, finger/joint pain/arthritis, nail pitting,  Elevated ESR/CRP, Rhamtoid factor ngative 

Psoriatic arthritis treatment

NSAIDs

methotrexate

TNF inhibitors

Reactive arthritis (Reiters) Def / s/s

Arthritis that usually comes after an STI or GI infection 

Arthritis + urethritis + conjunctivitis post-GI/STI

Cant see, cant pee, cant walk 

Reactive arthritis treatment

NSAIDs; prolonged antibiotics if chlamydia-associated

HLA-B27 gene 

a gene associated with an increased risk of autoimmune diseases, including ankylosing spondylitis and reactive arthritis.

Nongonococcal Acute Bacterial Septic arthritis. Def and S/S

Infection of the joint space. Leukocytits, fever chills, inflamed joints, 

Septic arthritis risk factors

IV drug use, ENDOCARDIITS, joint replacements,

Septic arthritis organisms

S. aureus, E. coli, Pseudomonas

Septic arthritis treatment

Hospitalize, IV antibiotics

Gonococcal arthritis def s/s

Goncoccal infection that spread to the joints. S/S; 1.Tenosynovitis , Purulent monoarthritis, general infection symptoms and skin lesions around infected joint

Gonococcal arthritis treatment

Ceftriaxone + azithromycin

Osteomyelitis

Bone infection (S. aureus common);

ESR/CRP; MRI sensitive

Osteomyelitis treatment

Long antibiotics

surgical debridement

Sarcoidosis definition s/s and hallmark factoid

Multisystem inflammatory disease with non-caseating granulomas; brownred patches on skin, arthritis

Sarcoidosis organs

Lungs, lymph, skin, eyes, heart

Sarcoidosis CXR

Bilateral hilar adenopathy

Sarcoidosis labs

ACE, hypercalcemia

Sarcoidosis diagnosis

Biopsy

Sarcoidosis treatment

Prednisone

methotrexate/azathioprine if chronic

Lupus pernio

Chronic facial sarcoidosis lesion

Sarcoid hematologic

Lymphopenia, anemia

Sarcoid cardiac

Arrhythmia or heart failure risk