Immuno
A pt with known SLE presents to the clinic, in which he was found to have tea-coloured urine. Which type of hypersensitivity is this associated with this presentation?
Ans: Type III
Level 1: SLE is has 2 types of hypersensitivity associated with it: Type II & III
Level 2: Tea-coloured urine is suggestive of glomerular damage causing RBC casts to occur in the urine.
Level 3: Knowing that glomerularnephritis is due to anti-dsDNA complex deposition. This means the hypersensitivity type here is Type III.
Additionally, the other type III is due to dermal-epidermal junction complement deposition causing rash + auto-Ab against platelets & WBC causing thrombocytopenia, leukopenia, neutropenia
A 25-year-old woman presents with painful stiff neck, photophobia, and an evolving non-blanching rash. What is the most likely causative organism?
Neisseria meningitidis
A 60-year-old man presents with "suffocating" chest pain. ECG shows ST elevation in leads V1–V4. Which artery is most likely occluded?
Left anterior descending
Explain why (including mechanism) for why buprenorphine is formulated with naloxone in a tablet form for opioid use disorder?
When taken orally, naloxone has no oral bioavailability, however, if the patient tries to tamper with the tablet by crushing and snorting, the naloxone would antagonize the partial agonist effect of buprenorphine, precipitating withdrawal symptoms, thus preventing tampering.
An elderly man who has smoked all his life is seen in the respiratory clinic for follow up of his emphysema. What changes on his lung function testing would you expect to see regarding residual volume and vital capacity?
Increased RV, decreased VC
19 y/o M presents with 2 wk hx of diarrhea, abdo cramping & bloating. He returned from a trip to Southeast Asia 6 wks ago. Stool sample confirms a Ascaris lumbricoides infx (eggs & larvae consistent w roundworm infx).
What antibody provides immunity to this organism (Ig?)
IgE
What are the 5 symptoms associated with Measles (that isnt fever)?
Cough, coryza, conjunctivitis, Koplik spots, Rash
67 y/o man presents to GP w worsening swelling of ankles & progressive exertional breathlessness for past 9 months.
On examination, his BP : 149/89mmHg, and his ankle edema was bilateral and pitting. Auscultation of lung fields reveals bi-basal crackles.
He was sent to get an echo which shows his Ejection fraction was 35%.
You decided to add a medication to better manage the pt's condition & improve long-term prognosis
What drugs would you provide?
RAASi
Beta blocker
MRA (Mineralocorticoid Receptor Antagonists)
SGLT2i
What is the clinical use of rivastigmine vs pyridostigmine?
Both acetylcholinesterase inhibitors.
Pyridostigmine: myasthenia gravis
Rivastigmine: Alzheimer's disease
A 7-year-old boy is brought to the pediatrician because of chronic cough, greasy floating diarrhea, and failure to gain weight. Pseudomonas aeruginosa is grown from his sputum culture. He is found to have the gene mutation that is the most common cause of his disorder. What is the possible mutation and what is its normal function?
CFTR
Lungs/GI tract: moves chloride ions out of cells; thick mucus/bronchiectasis/fat-soluble vitamin deficiency/meconium in infants
Skin: reabsorb sodium and chloride into cells; excessively salty sweat/dehydration
A newborn male noted to become cyanotic when feeding & crying. It was noted that the infant has a cleft palate, small head, smooth philtrum & epicanthic folds.
Given the most likely diagnosis, list 2-3 possible risks that the child likely has.
Level 1: Understanding the child has DiGeorge syndrome (22q11)
Level 2: Symptoms/signs of this syndrome (CATCH-22)
Symptoms of this condition can be remembered by CATCH-22:
C - Cardiac anomalies (particularly Tetralogy of Fallot)
A - Abnormal facies
T - Thymus hypoplasia - leading to recurrent infections
C - Cleft palate
H - Hypoparathyroidism leading to hypocalcaemia
22 - Location of deletion
A 29-year-old man returns from a camping trip where he noticed a tick attached to his skin. The site eventually developed into a well-demarcated, tender papule with a black eschar. Microscopic evaluation of a sample obtained reveals intracellular gram-negative coccobaccili. What is the organism most likely responsible?
Francisella tularensis
A 67-year-old man presents to the GP complaining of increasing shortness of breath over the past week, mainly when lying down, and leg swelling. His medical history includes hypertension and type 2 diabetes mellitus.
Physical examination reveals bilateral pitting oedema in the lower extremities and bibasal crackles on chest auscultation. No murmurs are heard.
Blood tests reveals a proBNP of 1056 ng/L (norm: <400)
What is the cause for the abnormality in blood test?
Ventricular strain
A 62-year-old man dies 8 months after coming to the hospital because of left-sided weakness, difficulty walking, double vision, and new-onset seizure activity. He had uncontrolled HIV. His mini-mental status examination was 22/30. T1-weighted MRI of his brain showed numerous nonenhancing white matter lesions. What was the likely pathogen causing this patient's presentation and eventual death?
JC virus reactivation causing Progressive multifocal leukoencephalopathy (PML)
A 21-year-old woman with a history of asthma comes to her primary care physician because of a 3-week history of increased wheezing and associated shortness of breath. She has been using her albuterol inhaler more frequently, including nights, and says that it does not work as well to control her symptoms. A new daily-use inhaled medication is prescribed to control her symptoms, and the patient is advised to rinse her mouth with water after each use of this new agent in order to avoid an oral infection. What class of medicine is most likely prescribed and what is the mechanism?
Corticosteroids. Inactivates NF-κB
30 y/o pt w ESRF (end-stage renal failure) 2' to polycystic kidney disease underwent a blackmarket kidney transplant overseas. Unfortunately a fully matched donor was not identified but despite the potential risk of rejection, he proceeded w it nonetheless.
Within minutes of the transplant, the patient displays features of rejection & hence the donor's kidney was removed and transplant was abandoned, and the pt wasted SGD$67,6767.
What immune cell mediated this reaction?
B cells
In this hyperacute setting, this is a Type II hypersensitivity reaction. Prior sensitization could be due to past transfusions or transplants or pregnancies. Preformed Ab deposition + complement activation occurred within mins.
A 76-year-old woman was diagnosed with pneumonia and treated with cefoxitin. Later, blood cultures revealed Klebsiella pneumonia and a second antibiotic was added for broader coverage. Nine days later, the patient's pneumonia improves but urine output drops, serum creatinine rises, and urine microscopy shows dark brown casts and renal tubular epithelial cells. What is the class of antibiotic that was added to her regimen and what did it cause?
Aminoglycosides (causes renal tubular acidosis / nephrotoxicity)
A 45 y/o female pt with known Turner's syndrome presents to the ED with breathlessness of unknown duration. On examination she has weak femoral pulse and systolic murmur. A chest X-ray was performed and the radiologist calls you to tell you of a particular finding seen at the posterior edges of her ribs.
Given her likely diagnosis, what is the likely non-medication intervention suggested for this pt?
Balloon dilation & stenting OR end-to-end anastomosis across the coarcted area
Level 1: Suggestion of coarctation of the Aorta
Level 2: Rib notching finding was likely the finding by the radiologist and hence the coarctation is likely post-ductal + given that she has survived till 45 y/o and asymptomatic previoulsy
Level 3: Knowing that surgical intervention or stenting is approach to this case.
A 77-year-old man presents with clinic with complaints of trouble reading, developing gradually over the past year. He has increasing difficulty seeing things in the center of his vision. He is otherwise healthy. He has 50-pack-year history of smoking. Visual acuity is decreased bilaterally, formal testing showing severe loss of central vision with intact peripheral vision. What would you find on a fundoscopy in this patient (name at least 1 of 2)?
Extracellular lipid deposits (Drusen) + geographic atrophy of retinal pigment epithelium (RPE) in dry age-related macular degeneration
A 72-year-old man is brought to his physician's office by his daughter because of a 2-week history of left upper extremity weakness, hoarseness, and visual disturbance. He has a 30-pack-year smoking history. Physical examination reveals pulse 80/min and blood pressure of 138/92 mmHg. His right pupil is larger than the left pupil, and the left eyelid droops down over the eye. The skin surrounding the left eye is dry.Which of the following is the most likely cause of this patient’s symptoms?
Pancoast tumor
56 y/o lady presents to ED w fevers & rigors. She also complains of dysuria & right-sided loin pain.
Observation: HR 125, BP 65/35 mmHg, T 38.8, RR 22, SpO2 95% on RA
What interleukin is responsible for the hypotension seen in this pt?
Ans: IL-1
Logic: Thinking likely sepsis due to possible infective source involving GU system + hypotension.
Additional Memory aid:
- IL-1 + IL-6 + TNF = think inflammation, vasodilation, fever
- Allergy (eosinophilic response) think 1,2,3,4,5 = Type 1 hypersensitivity, Th2 response, IL-13, IL-4, IL5
A 26-year-old male begins antimalarial chemoprophylaxis before travelling to Uganda. 3 days after starting the medication, he starts to feel excessively fatigued and notices that his urine is much darker than usual. Physical examination shows yellow sclerae. What medication did he start, and why did he have this reaction?
Patient has G6PD, was given primaquine, causing hemolytic anemia due to oxidative stress.
73 y/o rushed to ED following a collapse at home. Despite resus efforts, he passes away. It was noted in the E-HR that he suffered an MI 5 weeks ago. What would be the most likely histological findings on his heart?
(decreased cellularity + increased contraction)
A 4-year-old boy is brought to the clinic because of abnormal gait. Over the past year, he has had increased difficulty standing from a seated position, and needs his arm to support himself when getting up. His mother's brother had similar issues and died at a very young age. On physical examination, his gait is unsteady and there is bilateral diminished strength in his lower extremities. His gastrocnemius muscles are prominent and firm. What is the the likely diagnosis, and its inheritance pattern?
Duchenne muscular dystrophy, X-linked recessive
A 65-year-old woman comes to the emergency department because of progressive constipation. She reports smoking about a pack of cigarettes daily for 40 years. Physical examination is significant for coarse lung crackles in the left middle and lower zones. Serum studies show a sodium concentration of 137 mEq/L and a calcium concentration of 13.9 mg/dL. What is the likely diagnosis?
Non small cell lung carcinoma associated with a paraneoplastic syndrome caused by ectopic secretion of parathyroid hormone-related peptide (PTHrP), causing hypercalcemia and related symptoms.