Pathology: Autoimmunity Flashcards
A female comes to your clinic complaining of dry mouth, sore eyes and joint pain for the last six months. What autoimmune disorder might she have and how might it have developed?
Sjogren syndrome. A viral infection causing cell lysis could have brought tolerance escaped CD4 cells in contact with self antigen. CD4 cells then cause ductal epithelial cells to proliferate and block the duct.
So you think a patient has Sjogren’s syndrome. How do you make your diagnosis a concrete diagnosis?
Test for anti-ssa and anti-ssb antibodies, do Schirmer’s test and rose-bengal stain.
Presence of which antibody indicates a Sjogren’s patient with greater risk of non-Hodgkin lymphoma?
Anti-ssa
A female comes to the hospital with polyneuropathy. 6 years earlier she developed Raynaud’s phenomenon and swelling in her forearms, face and trunk. Physical exam shows an ulcer on her right thumb and she has a cough. Fine crackles are noted in both lower lungs. What antibody do you test for to confirm your diagnosis?
Scl-70 (anti-topoisomerase ab) to confirm DIFFUSE systemic sclerosis.
Your attending tells you the patient has CREST and to test their antibodies. What is CREST and what would you test for?
Calcinosis, Reynaud’s, Esophageal dysphagia, Sclerodactyly and Telangiectasia. All symptoms of limited scleroderma. You would test for anti-centromeric Ab.
An older man presents with orthopnea and nocturia that has been getting worse over the past few months. He complains of frequent greasy stools. Examination shows pulmonary edema. Tests show low albumin and proteinuria. What could you do to diagnose this patient’s condition?
A rectal biopsy with congo red stain. He has systemic amyloidosis from overproduction of light chain by B cells [AL]. These light chain proteins deposit all over the body and the rectum is the easiest way to test for them.
What kind of amyloids accumulate in rheumatoid arthritis?
AA from SAA precursor. These typically build up in chronic inflammation.
Why are people on dialysis prone to autoimmune disease?
Dialysis does not filter beta-2-microglobulin and causes amyloidosis. AB2m builds up.
What diseases result from transthyretin build up?
ATTR. Familial amyloidotic neuropathies and systemic senile amyloidosis.
A middle-aged male presents with progressive muscle weakness, facial edema in eyelids, difficulty swallowing, Grotton lesions and increased CPK levels. What infiltrate would you see in a muscle tissue section and what antibody would you test for to confirm your diagnosis?
Dermatomyositis. CD4 infiltrate near capillaries. Anti-jo-1 antibodies.
What’s the difference between dermatomyositis and polymyosistis?
PM has no skin involvement and CD8 infiltrate
One of your patients returned 2 weeks after a strep throat infection complaining of myocardial pain. You suspect rheumatic fever due to molecular mimicry. How do you confirm your diagnosis?
antitreptolysin o
A woman presents to the ER in septic shock. She hasn’t changed her tampon in a week. What pathogen is causing these symptoms?
Super antigen bacteria causing widespread T cell activation
A patient presents with all sorts of cancers: cerebral lymphoma, B-cell non-Hodgkins lymphoma and Kaposisarcoma. He also has pneumocystis. What antigen are you likely to detect in his blood?
p24. These are all classic secondary HIV diseases.
A patient complains of chronic sacroiliitis. What gene polymorphism is she likely to have and what do you think her condition is?
Ankylosing spondylosis. HLA-B27 gene.
The main mechanism of disease in this condition is IgE and IgG opsinization of self cells for lysis.
ADCC
Prostaglandins and leukotrienes are released by the mast cell in type I hypersensitivity. What cells come as a result?
Eosinophils, neutrophils, basophils, monocytes and CD4 cells.
A little boy presents with recurrent cytopenias and bacterial infections. What is he likely to have?
Hyper IgM syndrome. This is because IgM interacts with and clots blood. It also does not differentiate into IgG which fights bacterial infection.
A patient comes in with symptoms overlapping polymyositis, SLE and systemic sclerosis. What is the most likely antibody you might find in a serum test and why?
He probably has Mixed CT disease which will pop positive for u-ribonucleoprotein antibodies
This immunodeficiency is maternally inherited
agammaglobulinemia
Goodpasture syndrome
The patient has antibodies against type IV collagen and complement goes to work on the basement membrane.
What are all of the antibodies that point towards SLE?
Anti-DNA, anti-cardiolipin, anti-phospholipid, anti-RBC, and anti-Sm antibodies
Why do patients with lupus have longer thrombin times?
They have anti-phospholipid antibodies. These are the lupus anticoagulants.
A patient presents with renal failure, hemolytic anemia, cytopenia, endocarditis, sensitivity to light and “wire-loop” glomeruli. What do you think she has?
SLE
50% of SCID patients lack what?
Adenosine deaminase.
