Path Flashcards
How to monitor activity of SLE?
C3 and C4 levels
How to monitor patient with HIV?
WCC and differential.
Viral load is determined by PCR. Used to detect viral RNA to determine if virus is replicating
Antibody to diagnose someone with systemic sclerosis/scleroderma?
anti-toposiomerase aka anti-SCL-70
Management of flare of ANCA-assoc. vasulitis?
ie Wengeners, PAN, microscopic polyangitis
Induce remission with steroids and cyclophosphamide (or rituximab)
Maintain relapse by weaning off steroids and switch CYC to AZA or MTX (or continue rituximab)
Wean off biologic
Management of rheumatoid arthritis?
Induce remission with steroids and methotrexate.
Can add in a biologic like etanercept/infliximab/tocilizumab (based on what is cheapest) if inadequate control.
Rituximab is 3rd line if other dmards fail
Initial treatment is for 6 months then wean down dose as symptoms reduce. Increase if theres another flare.
Monotherapy for RA?
can use Adalimumab, etanercept, certolizumab or tocilizumab for monotherapy if methotrexate is contraindicated eg pregnancy or not tolerated
Systemic management of psoriasis?
Methotrexate or ciclosporin are first choice non-biologic systemic drugs. Monitor for hepatotoxicity with methotrexate.
If not responding to both, consider anti-TNF (adalimumab, etanercept, infliximab 2nd line) or anti-IL12 (ustekinumab)
Treatment of chronic granulomatous disease?
prophylactic trimethoprim and itraconazole.
INF-gamma for immunomodulation
Biologic used in treatment of osteoporosis?
Denosumab
how to manage acute attack of swelling in C1 inhibitor deficiency?
IV C1 inhibitor.
Chronically reduce freq. with tranexamic acid or regular C1 injections
What is the difference between H1 and H2 antagonists?
H1 are used to treat allergic reactions examples cyclizine, loratadine, promethazine, cetirazine
H2 are used to reduce gastric acid secretions egs cimetidine, ranitidine
Which HIV antigen do neutralising antibodies bind to?
envelope glycoprotein gp120 and gp41
Very specific to a certain region on HIV1 viruses
Which HIV antigens are non-neutralising antibodies produced against?
Most Env (viral envelope protein) are non-neutralising
Anti p24 (caspid protein) are non-neutralising
NB, body can also produce non-neutralising antibodies to monoclonals eg anti-TNFs like etanercept
What coreceptors on T-cells are required for viral entry?
CXCR4 and CCR5
What drugs are used for HIV antiviral therapy and how do they work/what is the target?
Nucleoside reverse transcriptase inhibitors (nucleoside analogues so competitive inhibition)
Non-nucleoside reverse transcriptase inhibitors (non-competitive inhibition)
Integrase inhibitors inhibit integration of viral DNA into host cell DNA
Protease inhibitors block viral enzyme which cleaves proteins necessary to form mature virions
6 month old with failure to thrive and recurrent infections. T cells undetectable and B cells normal, reduced antibody levels.
X-linked SCID.
Defect of IL2 receptor means no t cells and no maturation of B cells
Young person with recurrent episodes of meningococcal sepsis - what is likely immunodeficiency?
Complement deficiency. Def of any in the terminal pathway (C3,5,6,7,8,9) predispose to meningococcus and pneumococcus
What is the likely deficiency if CH50 test only is abnormal?
C4 most likely. Could be C1 or 2
What is the likely deficiency if AP50 test only is abnormal?
Factor B, I or P
Predisposes to encapsulated bacterial infection
Hib, pneumococc, meningococc, GBS, klebsiella, salmonella, e.coli
What vaccines should be avoided in the immunocompromised?
Live vaccines: Smallpox Yellow fever Typhoid Chickenpox MMR (still give in HIV unless severely immunocompromised) BCG oral polio (sabin)
What vaccine is given to asplenic patients and repeated every 5 years?
pneumovax
What vaccine is part of routine schedule but avoid in immunodeficiency?
MMR
ok in HIV or diGeorge if no evidence of severe immunocompromise
Which vaccine is a component vaccine consisting of viral haemagglutinin?
influenza
What are the target INRs for warfarin therapy?
2.5 (2-3) for most indications eg VTE, AF, biologic prosthetic valve etc
A target of 3 (2.5-3.5) is indicated for a mechanical aortic valve
A target of 3.5 (3-4) is indicated for a VTE while on anticoagulants or a mechanical mitral valve
warfarin overdose, INR 5-8 with no bleeding
stop warfarin restart when under 5
Warfarin overdose INR 5-8 with minor bleed
Stop warfarin, slow Vit K IV. Restart warfarin when INR
Warfarin overdose, INR>8 with no bleed
Stop warfarin, seek specialist advice, Oral Vit K. Repeat in 24hr if INR still high. Restart warfarin if INR
Warfarin overdose, INR>8 with minor bleeding
Stop warfarin. Arrange admission for IV Vit K. Daily INR check. Restart warfarin when INR
Warfarin overdose (INR above therapeutic range) and major active bleeding
Stop warfarin, Urgent admission. IV Vit K and dried prothrombin complex (Factors II, VII, IX, X)
Immediate transfusion reaction where patient has a high fever
Bacterial contamination. If temp rises above 39C or by more than 2C
Immediate transfusion reaction where patient has anaphylaxis. Has had another transfusion years ago
IgA deficiency
Patient suffers acute sever trauma, transfused with O- blood as emergency. Then loses consciousness a few mins after transfusion
Most likely internal hemorrhage
Immediate transfusion reaction, sudden onset dyspnoea with hypotension
TRALI
Immediate transfusion, sudden onset dyspnoea. Normotensive or hypertensive. Raised JVP
TACO -(fluid overload)
Immediate transfusion reaction. Fevers, chills, pain at site of transfusion, nausea/vomiting, BP drop, dark urine.
Confusion or possibility for error in samples sent
ABO incompatibility - acute haemolytic reaction. STOP transfusion. IV saline and diuretics. Keep blood for testing
Immediate transfusion reaction. Fevers, chills. Temp rise by less than 1C
Febrile reaction. Give paracetamol. Dont stop transfusion
Most common hereditary thrombophilic disorders
Factor V Leiden
Prothrombin G20210A
Rarer hereditary thrombophilias
Antithrombin III deficiency,
Protein C deficiency
Protein S deficiency
Recurrent miscarriages, hypercoagulable, assoc with SLE
Antiphospholipid syndrome
Pregnant woman develops seizures. Shes anaemic and jaundiced. Schistocytes seen on blood film. Febrile with neuro syx. PT and APTT normal
TTP/HELLP syndrome.
NOT DIC b/c of neuro symptoms and normal coagluation cascade (dysregulated in DIC)
The clots in TTP are aggregated platelets cf DIC where they are fibrin clots
Pregnant woman. Chorioamnionitis. Becomes septic. Bruises form. PT and APTT prolonged.
DIC
30/40 pregnant lady. Antenatal care all normal. Develops nosebleeds/bleeding gums/easy bruising. Otherwise well.
Gestational thrombocytopenia.
Occurs in mid 2nd trimester onwards
May present asymptomatically with diagnosis on routine FBC (eg 28-week second screed)
Child with recurrent infection. Normal CD8 levels and absent CD4
Bare Lymphocyte Syndrome type 2
Type 1 is rarer. Deficient in CD8 and normal CD4
Boy presents at 1 yr with recurrent infections and failure to thrive. High levels of IgM. Low IgA and IgG. What is the deficiency?
CD40L deficiency. Causes Hyper IgM syndrome
CD40L def is X-linked recessive. Other types can be autosomal recessive
Person with normal Hb and positive sickle solubility test
Sickle cell trait
Patient with low Hb and positive sickle solubility test
Sickle cell anaemia
trait would have normal Hb
African man becomes jaundiced and anaemic after taking primiaquine and chloroquine for malaria
G6PD deficiency. X-linked. Drug trigger
Older man with splenomegaly, fatigue and anaemia. Peripheral film shows polychromasia and spherocytes
Hereditary spherocytosis
Polychromasia = reticulocytosis
55yr old woman. Incidental finding of isolated platelet count >600. On further questioning, she has noted gum bleeding and headaches/dizziness. She has mild splenomegaly.
Essential thombrocythema.
Treat with aspirin (antithrombosis) Anegrelide (inhibits platelet formation) and hydroxycarbamide (anitmetabolite and BM suppression)
3-month old admitted for pneumonia. White cells are up, Platelets are 510. What is the cause of the thrombocytosis?
Reactive (secondary) thrombocytosis
70 yr old man is feeling increasingly tired. Bloods show he is anaemic and has raised platelets and neutrophilia
CML
A vegetarian lady presents feeling tired. She has a low Hb and platelets are 470
Iron deficiency raises platelets
An afrocarribbean boy has anaemia and a raised platelet count and a palpable spleen
Sickle cell causes hyposplenism, which can cause a reactive thrombocytosis
A man has a routine hernia repair. After the surgery his platelets go up
Reactive thrombocytosis secondary to surgery
Infection in pregnancy: what is a flagellate protozoan that can cross the placenta?
Toxoplamsa gondii
Infection in pregnancy - what is an STI previously beleived to only cross the placenta in the third trimester?
syphilis
Infection in pregnancy that can be teratogenic if mother eats unpasteurised cheeses?
Listeria
Normal maternal commensal that can cause neonatal sepsis
GBS
STI that can cause neonatal conjunctivitis
Chlamydia or gonorrhoea
Most common UTI
E. Coli
Most common UTI in young women
E. Coli
What would suggest contamination of an MSU sample?
epithelial cells on microscopy
What would suggest coliform organism causing UTI?
Nitrites
A man presents with pyelonephritis and renal stones. What is the likely organism?
Proteus (increases alkalinity which causes struvite and calcium carbonate stone formation)
A child is born with hydrocephalus, chorioretinitis and intracranial calcifications
congenital toxoplasmosis
A child is born with microcephaly, retinitis and intracranial calcifications
congenital CMV
Rice water stool
CHolera
a 30 yr old presents with clusters of nodules and papules on his hand. He installed a fish tank in his home 3 weeks ago. It is diffucult to grow, and eventually cultured at 33C
Mycobacteria marinarum (aquarium granuloma) Classically on the elbows and knees when assoc with swimming pools. Hands for fish/pet shop owners
a man returns from africa with a scaling ulcer on his arm. He thinks we was bitten by an insect. Diagnosis confirmed by PCR
cutaneous leishmaniasis. L. major or L. tropica
RUQ pain and fever in traveler returning from thailand
HAV
early onset neonatal sepsis
late onset neonatal sepsis
> 48hrs
coag negative staph, GBS, e coli, listeria
Give fluclox and gent.
taz and vanc 2nd line
3 month old with sepsis and irritability. LP microscopy shows gram +ve bacilli
Listeria monocytogenes. Amoxicillin
Meningitis, G -ve cocci
meningococcus
Smoker, Meningitis, G+ve cocci in chains
strep. pneumoniae
neonate, meningitis, G -ve rods/bacilli
E.coli (gent)
Commonest cause of gastroenteritis
Rotavirus
What investigation would you order to confirm C diff
ELISA is quick but not as sensitive as culture, which takes longer and should only be done if watery diarrhoea
ELISA shows toxin A
How to confirm salmonella/shigella in patient with diarrhoea after a barbeque?
Stool culture
Commonest cause of gas gangrene?
Clostridium perfringens
Limb is oedematous, discoloured, necrotic bullae. Crepitations may be heard on palpation
Commonest causes of cellulitis?
Group A strep (pyogenes), Staph aureus
Red, swollen, warm, well-demarcated erythematous rash, blistering, patient feverish. ASOT positive
Erysepelas.
Caused by GAS (strep pyogenes)
Soldier returns from afghanistan. Has a skin lesion
cutaneous leishmaniasis
DRug regime for HepB?
PegINF alpha, entecavir, tenofovir
Drug regime for HepC?
PegINF alpha and ribavirin
Prophylaxis for vertical transmission of HIV?
Nevirapine
Given with zidovudine as well
antiviral for CMV
gancivlovir or valganciclovir
antivirals for HSV
Act Very Fast
acyclovir, valacyclovir, foscarnet
Normal Ranges for Blood gases? pH CO2 Bicarb(HCO3) O2 Anion gap?
pH: 7.35-7.45 CO2: 4.7-6.0 kPa Bicarb: 22-30 mmol/l O2: 10-13 kPa Anion gap 14-18
Vegan lady feels tired. Shes anaemic with normal ferritin. Whats the cause?
B12 deficiency
A patient lacks intrinsic factor and feels tired. Whats the cause
pernicious anaemia- B12 deficieny. Anti-IF or anti-gastric parietal cell antibodies
A woman with hypothyroidism, T1DM, and adrenal failure has a routine blood film that shows anaemia. Why?
B12 deficiency. Multiple autoimmune endocrinopathies means likely to be pernicious anaemia
A patient with Crohns has a megaloblastic anaemia. Why?
B12 deficiency. Terminal ileum commonly affected and required for B12 absorbtion. But could be IDA or anaemia of chronic disease
Patient has low calcium, low phosphate, high PTH and high ALP. Whats the cause?
Vit D deficiency causing 2nd hyperparathyroidism
Isolated raised ALP
Pagets disease, pregnancy
Raised ALP and raised GGT
Cholestasis eg gallstones
Raised transferases. AST:ALT ratio 2:1, raised GGT
alcoholic liver disease
Raised transferases. AST:ALT ratio 1:1
Viral hepatitis
Patient with bowel cancer has raised GGT
Metastases
A boy presents with intellectual disability, involuntary movements and self-harming behavours. He is found to have megaloblastic anaemia and hyperuricaemia. His mother has a history of gouty arthritis. What enzyme does he lack?
Hypoxathine-guanine phosphoribosyltransferase (HGPRT)
This is Lech-Nyhan syndrome. X-linked recessive disease defined by triad of neurological dysfunction, cognitive/behavioural problems and hyperuricaemia.
What enzyme is needed for the rate-limiting step in haem synthesis?
ALA synthase
What metalloprotein is raised in Beta thalassemia?
HbA2
A boy presents with hyperkalemia. What enzyme defect could cause this?
21-alpha hydroxylase deficiency (CAH)
What enzyme is raised in mumps infection?
Amylase. Also raised in pancreatitis
A 70-yr old lady who lives alone fell and broke her hip on Saturday morning. She couldn’t get up and was found two days later when her carer came on Monday. What enzyme will be raised?
Creatine Kinase (CK-MM) Rhabdomyolysis
What biochem results would you expect in osteomalacia?
low calcium, low phosphate, hight PTH, high ALP, low vit D
What biochem results would you expect in osteoporosis?
Normal bone studies
What biochem results would you expect in primary hyperparathyroidism?
high calcium, high or normal PTH
What calcium results would you expect in squamous cell carcinoma?
High calcium, low PTH (appropriately suppressed)
What biochem results would you expect in primary hypoparathyroidism?
Low calcium, Low PTH/normal PTH (PTH should be high if calcium is low)
What potassium would you expect in untreated DKA?
raised potassium (>5.5)
How do you calculate osmolarity?
2(Na+K)+urea+glucose
Formula for anion gap?
Na+K-Cl-HCO3
Formula to calculate GFR/creatinine clearance?
(urine creatinine concentration * urine output in ml/min)/plasma creatinine concentration
What bicarb would you expect in pyloric stenosis?
High (>30)
What values would indicate impaired glucose tolerance?
7.8-11.0 inclusive
What values would indicate impaired fasting glucose? (WHO)
6.1-6.9 inclusive
What U+Es would you expect in HONK?
osmolarity >320, hypernatremia, hypokalaemia, glucose high, acidotic, low bicarb
What U+Es would you expect in DKA?
Na may be high bc of dehydration, low because of interference in assay by glucose and ketones or normal
K will be high if untreated, will fall with treatment
What U+Es would you expect in diabetes insupidus?
High sodium.
What U+es would you expect in Conns syndrome?
High sodium, low K, hyperosmolar
Occupational lung disease leading to fibrosis. Tends to affect the upper lobes
Pneumoconiosis
Most types affect the upper lobe
Asbestosis tends to affect the lower lobe
Occupational lung disease. Farmer with progressive SOB, dyspnoea, cough and weight loss. Finger clubbing noted
Extrinsic allergenic alveolitis
Acute form presents with fever, chills and cough hours after inhaling allergen
Smoker with progressive cough, lethargy and neuro signs. Bloods show low sodium
Small cell carcinoma causing SIADH
75 yr old ex-construction worker presents with progressive dyspnoea and weight loss. CXR shows a large right sided pleural effusion
Mesothelioma
Assoc w/ Asbestos exposure. 25-40yr latent period
Indictions for colectomy in UC
Dysplasia or adenocarcinoma found on screening biopsy
Uncontrollable symptoms/failed medical management
Systemic complications from medication
Toxic megacolon
What would you see on histology in Crohns disease?
non-caseating granuloma, transmural inflammation
Man is investigated for longstanding diarrhoea. Continuous lesion seen on sigmoidoscopy. Whats the diagnosis?
UC
In what disease is serum Copper high, causing basal ganglia toxicity?
Wilsons.
Can cause parkinsonism, psychosis and dementia
What disease is ANA positive and liver biopsy shows lymphocytic infiltration?
autoimmune liver disease
A patient has portal hypertension and on biopsy his liver shows micronodular cirrhosis
alcoholic cirrhosis
a 40 yr old woman presents with fatigue, itching and abdominal discomfort. ALp is raised, Antimitochondrial antibody is positive, US shows no dilatation of the ducts and biopsy shows bile duct loss with granuloma formation
Primary biliary cirrhosis
Man with UC presents with jaundice. Liver ultrasound shows bile duct dilatation. ERCP shows beading fo the bile ducts
Primary sclerosing cholangitis
Cushingoid features. High serum cortisol with low serum ACTH. Cortisol fails to suppress after high dose dexamethason
Cortisol-producing adrenal tumour
Which thyroid cancer is associated with the RET protooncogene?
Medullary
What substance may be found deposited in pancreatic islets that may cause T2DM?
Amyloid
A 55yr old woman with large hands presents with diarrhoea and a neck mass. FNA shows calcitonin staining
medullary thyroid cancer.
Mostly caused by MEN2 or familial MTC (RET mutation)
Calcitonin can be used as treatment marker. Radioidine isnt useful
30 yr old woman presents with a single asymptomatic neck lump. FNA shows mixed papillary and follicular architecture, clearing of cytoplasmic chromaffin and pathognomic nuclear changes.
Papillary carcinoma. Can be difficult to differentiate from follicular as can have mixed or entirely follicular histology. Diagnosis is looking for nuclear signs like nuclear overlapping,
Young woman with mobile breast mass
fibroadenoma
Endometrial cancer that presents in perimenopausal women and is related to oestrogen excess
Type 1 (endometrioid) endometrial cancer
Endometrial cancer that presents in elderly women with endometrial atrophy
Type2 (non-endometrioid) endometrial cancer
40 yr old woman presents with bloody nipple discharge and no palpable mass
Duct papilloma
70 yr old woman presents with a hard, craggy breast mass. On examination there is nipple retraction and peau d/orange
Invasive ductal carcinoma (most common invasive breast carcinoma)
65 yr old woman presents with rough, reddened skin and a fissure on her nipple. It hasn’t responded to emollients or corticosteroids
Paget’s disease of the breast
Begins with eczema-like rash. May have discharge or a burning sensation. Can progress to nipple inversion and breast changes
What would you expect to see on post-mortem of a person with alzheimers
Tau protein, beta-amyloid plaques
Thunderclap headache, berry aneurisms. Assoc with PKD and ehlers-danlos
subarachnoid haemmorhage
patient hit head a few days ago. Presents with fluctuating consciousness
subdural
35 yr old man has a 3 month history of anxiety and paranoia. He now presents with glove and stocking numbness and ataxia. He is not a vegetarian.
variant CJD.
From exposure to BSE.
neuro signs include peripheral neuropathy, ataxia, chorea and dementia
