Given the following values, calculate the RPI Observed reticulocyte count - 6% Hct- 30%

Correct Answer: A

Rationale: The correct answer is A (2). RPI (Reticulocyte Production Index) is calculated as: Observed Reticulocyte Count (%) x (Patient's Hct/Normal Hct). Given values: Observed reticulocyte count=6%, Hct=30%. Therefore, RPI = 6% x (30%/45%) = 6% x 0.67 = 4.02 ≈ 4. Since RPI is rounded to the nearest whole number, the correct RPI would be 4. Therefore, the correct answer is A (2). Other choices (B, C, D) are incorrect as they do not result from the correct calculation of RPI.

Correct Answer: B

Rationale: The correct answer is B: Easy bruising. Immune thrombocytopenia purpura is characterized by low platelet count, leading to easy bruising. Fever (A) and joint pain (C) are not typical symptoms of ITP. Hair loss (D) is not associated with this condition. Easy bruising is a key sign due to decreased platelets preventing proper blood clotting.

Correct Answer: B

Rationale: The correct answer is B: RBC protection against oxidative damage. Glucose-6-phosphate dehydrogenase (G6PD) enzyme plays a crucial role in protecting red blood cells (RBCs) from oxidative damage by generating NADPH, which helps in neutralizing reactive oxygen species. G6PD deficiency leads to RBCs being more susceptible to oxidative stress, causing hemolysis. Choice A (Clotting factor production) is incorrect because G6PD is not directly involved in clotting factor production. Choice C (Platelet activation) is incorrect as G6PD deficiency does not affect platelet activation. Choice D (White cell proliferation) is incorrect as G6PD deficiency primarily affects RBCs, not white cell proliferation.

Correct Answer: C

Rationale: The correct answer is C because minor histocompatibility antigens, which are not matched in a 2-haplotype MHC-matched kidney transplant from a relative, can still trigger an immune response leading to graft rejection. This is why immunosuppression is still necessary. A: Graft-versus-host disease would not be a problem in this scenario as the recipient is receiving a kidney transplant, not bone marrow. B: This choice is redundant with the correct answer. Matching minor histocompatibility antigens is crucial for reducing the risk of rejection. D: Complement components do not play a significant role in graft rejection in this context.

Correct Answer: B

Rationale: The correct answer is B: vascular permeability. C3a and C5a are anaphylatoxins that can cause increased vascular permeability, leading to fluid leakage and inflammatory responses. They do not directly cause bacterial lysis (choice A), phagocytosis of IgE-coated bacteria (choice C), or aggregation of C4 and C2 (choice D). Increased vascular permeability is a key mechanism by which these complement proteins contribute to inflammation and immune responses.