USMLE Step 1 Immune Latest Exam
2025-2026 Questions and All Correct
Answers Rated A+.
IMMUNO/PATH - Answer
Catalase + organisms
- In what disease are patients more susceptible and why? - Answer PLACESS
Pseudomonas, Listeria, Aspergillus, Candida, E.coli, S. aureus, Serratia
- CGD, because they lack NADPH oxidase needed for the respiratory burst and usually rely on
their Peroxidase, but these Catalase + organisms inhibit that Peroxidase
How do free radicals cause damage? - Answer Tide PODs are bad
Peroxidation of lipids
Oxidation of proteins
DNA damage
Carcinomas that spread hematogenously rather than through lymphatics? - Answer Four
Carcinomas Route Hematogenously
Follicular thyroid carcinoma
Choriocarcinoma
Renal cell carcinoma
Hepatocellular carcinoma
Antibiotics that inhibit protein synthesis? - Answer buy AT 30, CCEL at 50
30S ribosomal subunit:
Aminoglycosides
,Clindamycin
Erythromycin
Linezolid
Cytokines mnemonic? - Answer Hot T-Bone stEAK
Il-1: Fever
Il-2: T-cell stimulation
Il-3: Bone marrow stimulation
Il-4: class switching to IgE (and IgG)
Il-5: class switching to IgA
Il-6: aKute phase protein stimulation
Cytokines secreted by Th1 cells? Th2? - Answer Th1: 1, 2, "3":
- Th1's secrete:
- 1l-2: stimulates growth of all T-cells
- 3= IFN-gamma (third letter in greek alphabet): stimulates macrophages and inhibits Th2
differentiation since Th2 cells secrete Il-10 which inhibits macrophages and dendritic cells;
increases MHC expression
Th2: 4, 5, 10
- Il-4: induces Th2 cells and promotes B cell growth and class switching to IgE and IgG
- Il-5: class switching to IgA
- Il-10: attenuates immune response: inhibits macrophages and dendritic cells and decreases
MHC II and Th1 cytokines
Caspases contain what amino acid and cleave what? - Answer Contain cysteine, cleave
aspartic acid residues
Cysteine-ASPartic-acid-proteASES
Cytokines order of secretion? - Answer Keep the single digit interleukins straight because
they come in sequence.
,2. If the macrophages also produce IL-12, this will drive the Th cells to become Th1 cells (2 to
Th1, or "to" Th1).
3. If Th1 cells are induced, they will produce IL-2 (second cytokine in order) and both IL-3 and
IFN-gamma (gamma is the 3rd letter of Greek alphabet and represents the 3, too). The IFN-
gamma will activate cytotoxic T cells (CD8 T cells).
4. If the macrophages produce only IL-1, this will drive the Th cells to become Th2 cells. If Th2
cells are induced, they will produce IL-4, IL-5, and IL-6 (note that they follow in order) that drive
B cells to divide and differentiate into plasma cells that produce antibody.
5. Th2 cells also produce IL-10 ("zero Th1") which blocks macrophage production of IL-12 and
thus blocks activation of Th1 cells.
Acute phase reactants? - Answer More FFISHH in the C
more...
- Ferritin and Fibrinogen
- Il-6
- Serum amyloid
- Haptoglobin and Hepcidin
- C-reactive protein
Live attenuated vaccines? - Answer Attention Teachers! Please Vaccinate Small, Beautiful
Young Infants with MMR Regularly!
Adenovrius
Typhoid
Polio (Sabin)
Varicella
Smallpox
BCG
Yellow fever
, Killed vaccines? - Answer RIP HAppily
Rabies
Influenza (injection)
Polio (Salk)
Hepatits A
Pre-formed antibodies should be administered after what exposures? - Answer "To Be
Healed Very Rapidly before Dying"
Tetanus toxin
Botulinum toxin
HBV
Varicella
Rabies virus
Diptheria toxin
Segmented RNA viruses? - Answer BOAR:
Bunyavirus (3 circular segments)
Orthomyxovirus (8 segments)
Arenavirus (2 circular segments)
Reovirus
Congenital infections transmitted from mother to baby? - Answer TORCHeS
Toxoplasmosis
Other (Parvovirus B19, Varicella)
Rubella
CMV
HSV/HIV
2025-2026 Questions and All Correct
Answers Rated A+.
IMMUNO/PATH - Answer
Catalase + organisms
- In what disease are patients more susceptible and why? - Answer PLACESS
Pseudomonas, Listeria, Aspergillus, Candida, E.coli, S. aureus, Serratia
- CGD, because they lack NADPH oxidase needed for the respiratory burst and usually rely on
their Peroxidase, but these Catalase + organisms inhibit that Peroxidase
How do free radicals cause damage? - Answer Tide PODs are bad
Peroxidation of lipids
Oxidation of proteins
DNA damage
Carcinomas that spread hematogenously rather than through lymphatics? - Answer Four
Carcinomas Route Hematogenously
Follicular thyroid carcinoma
Choriocarcinoma
Renal cell carcinoma
Hepatocellular carcinoma
Antibiotics that inhibit protein synthesis? - Answer buy AT 30, CCEL at 50
30S ribosomal subunit:
Aminoglycosides
,Clindamycin
Erythromycin
Linezolid
Cytokines mnemonic? - Answer Hot T-Bone stEAK
Il-1: Fever
Il-2: T-cell stimulation
Il-3: Bone marrow stimulation
Il-4: class switching to IgE (and IgG)
Il-5: class switching to IgA
Il-6: aKute phase protein stimulation
Cytokines secreted by Th1 cells? Th2? - Answer Th1: 1, 2, "3":
- Th1's secrete:
- 1l-2: stimulates growth of all T-cells
- 3= IFN-gamma (third letter in greek alphabet): stimulates macrophages and inhibits Th2
differentiation since Th2 cells secrete Il-10 which inhibits macrophages and dendritic cells;
increases MHC expression
Th2: 4, 5, 10
- Il-4: induces Th2 cells and promotes B cell growth and class switching to IgE and IgG
- Il-5: class switching to IgA
- Il-10: attenuates immune response: inhibits macrophages and dendritic cells and decreases
MHC II and Th1 cytokines
Caspases contain what amino acid and cleave what? - Answer Contain cysteine, cleave
aspartic acid residues
Cysteine-ASPartic-acid-proteASES
Cytokines order of secretion? - Answer Keep the single digit interleukins straight because
they come in sequence.
,2. If the macrophages also produce IL-12, this will drive the Th cells to become Th1 cells (2 to
Th1, or "to" Th1).
3. If Th1 cells are induced, they will produce IL-2 (second cytokine in order) and both IL-3 and
IFN-gamma (gamma is the 3rd letter of Greek alphabet and represents the 3, too). The IFN-
gamma will activate cytotoxic T cells (CD8 T cells).
4. If the macrophages produce only IL-1, this will drive the Th cells to become Th2 cells. If Th2
cells are induced, they will produce IL-4, IL-5, and IL-6 (note that they follow in order) that drive
B cells to divide and differentiate into plasma cells that produce antibody.
5. Th2 cells also produce IL-10 ("zero Th1") which blocks macrophage production of IL-12 and
thus blocks activation of Th1 cells.
Acute phase reactants? - Answer More FFISHH in the C
more...
- Ferritin and Fibrinogen
- Il-6
- Serum amyloid
- Haptoglobin and Hepcidin
- C-reactive protein
Live attenuated vaccines? - Answer Attention Teachers! Please Vaccinate Small, Beautiful
Young Infants with MMR Regularly!
Adenovrius
Typhoid
Polio (Sabin)
Varicella
Smallpox
BCG
Yellow fever
, Killed vaccines? - Answer RIP HAppily
Rabies
Influenza (injection)
Polio (Salk)
Hepatits A
Pre-formed antibodies should be administered after what exposures? - Answer "To Be
Healed Very Rapidly before Dying"
Tetanus toxin
Botulinum toxin
HBV
Varicella
Rabies virus
Diptheria toxin
Segmented RNA viruses? - Answer BOAR:
Bunyavirus (3 circular segments)
Orthomyxovirus (8 segments)
Arenavirus (2 circular segments)
Reovirus
Congenital infections transmitted from mother to baby? - Answer TORCHeS
Toxoplasmosis
Other (Parvovirus B19, Varicella)
Rubella
CMV
HSV/HIV
