Musc Flashcards
What are the symptoms of osteomalacia
Bone pain/tenderness
Fracture (horizontal fractures at Looser’s zone at the neck of the femur are commonly seen)
Proximal weakness
Bone deformity
consequences of hyperparathyroidism
Hypercalcaemia (increased Ca2+ reabsorption)
Hypophosphataemia (increased phosphate excretion in the urine)
Osteitis fibrosa cystica (due to increased osteoclast activity)
indications for bone biopsy
Most of the time, you don’t need to do it because eg x rays is suffice
Confirm the diagnosis of a bone disorder
Find the cause of or evaluate ongoing bone pain or tenderness
Investigate an abnormality seen on X-ray
For bone tumour diagnosis (benign vs malignant)
To determine the cause of an unexplained infection
To evaluate therapy performance
2 main autoantibodies in RA
Rheumatoid factor
Anti-cyclic citrullinated peptide antibody
What family of diseases does ankylosing spondylitis belong to
seronegative spondyloarthropathies
location of inflammation in ankylosing spondylitis
enthesis - connects ligaments/tendons to bones
Normally happens to bones in the spine hence spondylo
Lupus causes multi-site inflammation but state some sites that are particularly badly affected.
joint, skin, kidney
SLE autoantibodies
Anti-nuclear antibodies
Anti-double stranded DNA antibodies
SLE is part of which family of diseases
connective tissue diseases
MHC associations of RA, SLE and AS (ankylosing spondylitis)
Rheumatoid arthritis – HLA-DR4
SLE –HLA-DR3
Ankylosing spondylitis – HLA-B27
diffuse systemic sclerosis antibody
Anti-Scl-70 antibody
anti-topoisomerase antibody
limited systemic sclerosis antibodies
Anti-centromere antibodies
Dermato-/Polymyositis
Anti-tRNA transferase antibodies
Mixed connective tissue disease
Anti-U1-RNP antibodies
What is the difference in the specificity of the autoantibodies in SLE?
Out of the 2 autoantibodies you need to know for SLE, which one of them correlates with disease activity?
Anti-nuclear antibodies are found in all cases of SLE BUT isn’t specific to SLE
Anti-dsDNA antibodies ARE specific to SLE
serum level of this antibody correlates with disease activity
What are the features of a sick lupus patient in terms of complement levels and serum levels of anti-dsDNA antibodies?
Low complement levels (used up)
High serum levels of anti-dsDNA antibodies (ie a lot of immune complexes)
Name a monoclonal antibody that targets RANKL.
denosumab
What is RANKL produced by and what does it do?
RANKL is produced by T cells, osteoblasts and stromal cells (means cells of connective tissue, eg synovial fibroblasts)
It stimulates osteoclast formation
RANKL can be upregulated by eg TNF alpha in RA which leads to osteoclast activation and bone destruction in RA. Hence there are drugs stopping RANKL
What drug targets CD20
What drug targets BLYS
What do these drugs do
Rituximab – anti-CD20 monoclonal antibody
Belimumab – anti-BLYS monoclonal antibody (BLYS is a B cell survival factor)
Reduces B cell survival
what do glucocorticoids do
phospholipase a2 inhibition
define RA
Chronic autoimmune disease characterised by pain, stiffness and symmetrical synovitis (inflammation of the synovial membrane) of synovial (diarthrodial) joints
what type of Antibodies are rheumatoid? (class, what do they bind to)
typically IgM antibodies, binds to Fc portion of the IgG
Name 2 deformities of RA if left untreated
Swan-neck deformity Hyperextension of PIP Hyperflexion of DIP Boutonniere deformity (button-like) Hyperflexion at PIP
which enzymes are involved in citrullination of arginine?
Peptidyl arginine deaminases (deamination because you are removing an amine group when converting arginine to citrulline)
what type of collagen is present in articular cartilage
type 2
3 dominant cytokines in the pathogenesis of RA
IL-1
IL-6
TNF-alpha
Reactive arthritis can cause enthesopathy. Which entheses are likely to get affected and what symptoms will that cause?
Achilles tendonitis
Dactylitis *
Metatarsalgia (painful feet because of inflammation of the palmar fascia)
*Ligaments in fingers insert into bones etc hence theres enthesis. Often presented as Swollen whole finger, not just joints (aka dactylitis)
