The misfits Flashcards
Antisynthetase syndrome
Rare inflammatory muscle condition that is closely associated with dermatomyositis and polymyositis. The kicker –> Interstitial lung disease, and the give away in questions. Anti-Jo 1 antibody
Prognosis is based on pulmonary disease
ECOG Scale
0 = fully active 1 = restricted but ambulatory and light work 2 = ambulatory and capable of all self care - but requires rest ~50% of the day 3= limited self care: bed or chair more than 50% 4= completely disabled, cannot self care 5 = dead
Granuloma annulare
Mediated by TNF alpha. Often occurs in areas that are knocked.
Disseminated form with mauve coloured patch associated with HIV.
Necrobiosis lipoidica
Rare disorder affecting the shin of insulin dependant diabetics. Can be round oval shaped or irregular
Hypersensitivity syndromes
Type 1 = Allergy, Allergen - IgE interaction with degranulation of mast cells
Type II = cytotoxic hypersensitivity
Type III = immune complex hypersensitivity
Type IV = Cell mediated
Hypersensitivity syndromes primary mediators
1 = IgE, 2 = IgG/M, as with 3, 4 CD4 and CD8
Type 1 hypersensitivity mechanism
Allergen-specific IgE antibodies bind to mast cells via their Fc receptor. When the specific allergen binds to the IgE, cross-linking of IgE induces degranulation of mast cells.
Type 2 Mechanism hypersensitivity
IgG or IgM antibody binds to cellular antigen, leading to complement activation and cell lysis. IgG can also mediate ADCC with cytotoxic T cells, natural killer cells, macrophages, and neutrophils.
Type 3 hypersensitivity mechanism
Antigen-antibody complexes are deposited in tissues. Complement activation provides inflammatory mediators and recruits neutrophils. Enzymes released from neutrophils damage tissue.
Type 4 hypersensitivity mechanism
Th2 cells secreted by cytokines which activate macrophages and cytotoxic T cells.
Type 1 hypersensitivity examples
Asthma, rhinitis, atopic eczema
Type 2 hypersensitivity examples
Rhesus incompatibility, transfusion reactions, cell destruction due to autoantigens, drug induced haemolysis
Type 3 hypersensitivity examples
GN, SLE, Farmers lung, vasculitis
Type 4 hypersensitivity
Tuberculin reaction, granuloma formation, allergic contact dermatitis, type 1 diabetes
Hypersensitivity reactions mnemonic
“ACID”
The “A” stands for Allergic/Anaphylactic (Type I), the “C” stands for Cell-triggered (Type II), the “I” is for Immune Complex Deposition (Type III), and the “D” stands for ‘Delayed’ (Type IV).
hypersensitivity examples mnemonic
AnGST –(as in, you’d probably feel angst about someone pouring acid on your skin.) A is for “anaphylaxis, asthma, atopy”, G for “Goodpasture’s disease, Grave’s disease, and myasthenia Gravis”, S for “Systemic lupus erythematous and serum sickness”, and T for “T-cell mediated diseases like the TB test and transplant rejection”.
Cardio/circulatory changes in pregnancy
Blood volume increases to 50% of that of normal circulating volume (by week 32)
Stroke volume initially increases to compensate, but later in the pregnancy it is in fact the heart rate that augments.
Pulse pressure widens as systemic vascular resistance falls
Purpose of gemfibrozil
Increase HDL levels and decrease plama triglyceride levels
MOA is unclear ? Stimulates lipoprotein lipase activity via peroxisome proliferator activated receptor alpha (PPARa)
Targets for cholestrol/LDL levels
total Chol <4 HDL >1 LDL <2 Non-HDL-C <3 TG < 2 `
Statin MOA
Competitively inhibits enzyme COA-reductase
Increase hepatic uptake of cholesterol from blood, reduce LDL, modestly reduce triglycerides and increase HDL
Ezetemibe MOA
Reduces absorption of dietary and biliary cholesterol.
This leads to upregulation cellular LDL receptors on the surface of cells and increased LDL cholesterol uptake into cells.
NAGMA
HCO3 loss and replaced with Cl- -> anion gap normal
if hyponatraemia is present the plasma [Cl-] may be normal despite the presence of a normal anion gap acidosis -> this could be considered a ‘relative hyperchloraemia’.
USEDCRAP
Ureteroenterostomies Small bowel fistula Excess Chloride Diarrhoea Carbonic anhydrase inhibitors Renal tubular acidosis Addisson’s disease Pancreatoenterostomies
What is a normal anion GAP
4-10
Commonest organism implicated in septic arthritis
Although Staphylococcus aureus is the most common cause of monomicrobial septic arthritis overall, among sexually active adults, N. gonorrhoeae is the most common causative organism
Congenital deficiency leading to recurrent Neisseria infections
Complement deficiency of C5,6,7,89, i..e can’t form MAC
How to differentiate inflammatory vs. infective synovial fluid
WBC count - typically >2000 in inflammatory but greater than 20,000 in septic
Non-inflammatory will be less than 2000
How to differentiate gout from pseudogout on crystal analysis
Monosodium urate crystals are brightly birefringent and are needle shaped
Calcium pyrophosphate crystals have a rhomboid shape or rectangle they are WEAKly birefringent.
I.E. the same as ‘pseudo’ gout they are ‘pseudo’ refringent
As a random tidbit - if lipids are seen ‘a maltese cross sign’ then suspect fracture
Place to do knee joint aspirate as per UpToDate
Medial epicondyle and patella as landmarks then aim postero-inferiorly
Primary signs of hyperaldosteronism
Hypertension and hypokalaemia +/- metabolic alkalosis
Low Renin and High aldosterone doesn’t clinich the diagnosis of primary hyperaldosteronism unless one of three factors is also present
The exception to the requirement for confirmatory testing is the patient with:
- Spontaneous hypokalemia
- Undetectable PRA or PRC
- PAC 555 pmol/L
