TABLE OF CONTENTS
SECTION 1: ALTERATIONS IN HEMATOLOGIC FUNCTION ...................... Questions 1-85
SECTION 2: ALTERATIONS IN IMMUNE FUNCTION ........................... Questions 86-145
SECTION 3: ALTERATIONS IN CARDIOVASCULAR FUNCTION ........... Questions 146-210
SECTION 4: ALTERATIONS IN RENAL FUNCTION ............................ Questions 211-260
SECTION 5: ALTERATIONS IN GASTROINTESTINAL FUNCTION ................. Questions
261-300
Page | 1
,SECTION 1: ALTERATIONS IN HEMATOLOGIC FUNCTION (Questions 1-85)
1. A patient with chronic kidney disease (CKD) stage 4 presents with fatigue and pallor.
Laboratory findings: hemoglobin 8.2 g/dL, MCV 78 fL, serum iron 30 mcg/dL, TIBC 400
mcg/dL, ferritin 150 ng/mL, and erythropoietin level inappropriately normal. Which
pathophysiologic mechanism best explains the anemia in this patient?
A) Iron deficiency due to decreased gastrointestinal absorption
B) Impaired erythropoietin production leading to inadequate erythroid precursor
stimulation
C) Chronic inflammation causing hepcidin-mediated iron sequestration
D) Folate deficiency from dietary restrictions
Answer: C
Rationale: In CKD, anemia results from a multifactorial process involving both
erythropoietin deficiency and chronic inflammation. The inappropriately normal
erythropoietin level for the degree of anemia suggests relative deficiency; however, the low
MCV with normal ferritin and elevated TIBC indicates functional iron deficiency due to
iron-restricted erythropoiesis. Hepcidin, an acute-phase protein upregulated by
inflammation, binds to ferroportin on macrophages and enterocytes, leading to
internalization and degradation of the iron exporter. This traps iron in macrophages and
reduces intestinal absorption, limiting iron availability for erythropoiesis despite adequate
total body iron stores. The normal ferritin in this case reflects acute-phase elevation rather
than true iron stores. Option A is incorrect because gastrointestinal absorption is not the
primary issue in CKD-related anemia; the problem is iron sequestration, not deficiency.
Option B is incorrect because erythropoietin is not low; it is inappropriately normal,
indicating relative deficiency. Option D is incorrect because folate deficiency would present
with macrocytic anemia (elevated MCV), not microcytic anemia.
Page | 2
,2. A patient with a history of recurrent deep vein thrombosis (DVT) and pulmonary
embolism (PE) is found to have a prolonged activated partial thromboplastin time (aPTT)
that does not correct with mixing studies. Which of the following is the most likely
underlying cause?
A) Factor V Leiden mutation
B) Antiphospholipid syndrome (APS)
C) Protein C deficiency
D) Antithrombin III deficiency
Answer: B
Rationale: A prolonged aPTT that does not correct upon mixing with normal plasma
indicates the presence of an inhibitor, such as a lupus anticoagulant, which is characteristic
of antiphospholipid syndrome (APS). Despite the prolonged aPTT in vitro, APS is a
hypercoagulable state due to the antibody's interference with the protein C pathway and
increased tissue factor expression, leading to recurrent arterial and venous thromboses.
Factor V Leiden mutation (A) is associated with normal aPTT and causes activated protein
C resistance. Protein C deficiency (C) also presents with normal aPTT and is associated
with venous thromboembolism. Antithrombin III deficiency (D) typically does not prolong
aPTT; it reduces the inhibition of thrombin and factor Xa, leading to hypercoagulability.
The lack of correction in mixing studies is the key distinguishing feature pointing to an
inhibitor rather than a factor deficiency.
3. A patient with sickle cell disease (HbSS) develops acute chest syndrome after a vaso-
occlusive crisis. Which of the following pathophysiologic mechanisms contributes most
directly to the development of acute chest syndrome?
A) Increased nitric oxide production leading to vasodilation and pulmonary congestion
B) Intravascular hemolysis causing free hemoglobin scavenging of nitric oxide and
endothelial dysfunction
Page | 3
, C) Bone marrow embolism from necrotic bone marrow
D) Pulmonary vasospasm due to cold exposure
Answer: B
Rationale: Acute chest syndrome in sickle cell disease is a life-threatening complication
characterized by fever, respiratory symptoms, and new pulmonary infiltrates. The
pathogenesis is multifactorial, but intravascular hemolysis plays a central role. Free
hemoglobin released from lysed red blood cells scavenges nitric oxide (NO) with high
affinity, reducing NO bioavailability. This leads to endothelial dysfunction, increased
expression of adhesion molecules (VCAM-1, ICAM-1), and vasoconstriction. These changes
promote adhesion of sickled erythrocytes to the endothelium, further vaso-occlusion, and
ischemia-reperfusion injury in the pulmonary microvasculature. Option A is incorrect
because NO is decreased, not increased, in hemolytic states. Option C (bone marrow
embolism) is a less common mechanism and typically occurs in long bone infarcts, not as
the primary driver of acute chest syndrome. Option D is incorrect because cold exposure
triggers vaso-occlusive crises but is not the direct mechanism for acute chest syndrome.
4. A patient with chronic lymphocytic leukemia (CLL) develops autoimmune hemolytic
anemia (AIHA). Which of the following laboratory findings would most likely be present?
A) Elevated haptoglobin and normal LDH
B) Positive direct antiglobulin test (DAT) with anti-IgG and anti-C3d
C) Low reticulocyte count and elevated bilirubin
D) Schistocytes on peripheral smear and thrombocytopenia
Answer: B
Rationale: Autoimmune hemolytic anemia (AIHA) is a common complication of CLL,
occurring in approximately 10-15% of patients. The warm antibody type, mediated by IgG
Page | 4
SECTION 1: ALTERATIONS IN HEMATOLOGIC FUNCTION ...................... Questions 1-85
SECTION 2: ALTERATIONS IN IMMUNE FUNCTION ........................... Questions 86-145
SECTION 3: ALTERATIONS IN CARDIOVASCULAR FUNCTION ........... Questions 146-210
SECTION 4: ALTERATIONS IN RENAL FUNCTION ............................ Questions 211-260
SECTION 5: ALTERATIONS IN GASTROINTESTINAL FUNCTION ................. Questions
261-300
Page | 1
,SECTION 1: ALTERATIONS IN HEMATOLOGIC FUNCTION (Questions 1-85)
1. A patient with chronic kidney disease (CKD) stage 4 presents with fatigue and pallor.
Laboratory findings: hemoglobin 8.2 g/dL, MCV 78 fL, serum iron 30 mcg/dL, TIBC 400
mcg/dL, ferritin 150 ng/mL, and erythropoietin level inappropriately normal. Which
pathophysiologic mechanism best explains the anemia in this patient?
A) Iron deficiency due to decreased gastrointestinal absorption
B) Impaired erythropoietin production leading to inadequate erythroid precursor
stimulation
C) Chronic inflammation causing hepcidin-mediated iron sequestration
D) Folate deficiency from dietary restrictions
Answer: C
Rationale: In CKD, anemia results from a multifactorial process involving both
erythropoietin deficiency and chronic inflammation. The inappropriately normal
erythropoietin level for the degree of anemia suggests relative deficiency; however, the low
MCV with normal ferritin and elevated TIBC indicates functional iron deficiency due to
iron-restricted erythropoiesis. Hepcidin, an acute-phase protein upregulated by
inflammation, binds to ferroportin on macrophages and enterocytes, leading to
internalization and degradation of the iron exporter. This traps iron in macrophages and
reduces intestinal absorption, limiting iron availability for erythropoiesis despite adequate
total body iron stores. The normal ferritin in this case reflects acute-phase elevation rather
than true iron stores. Option A is incorrect because gastrointestinal absorption is not the
primary issue in CKD-related anemia; the problem is iron sequestration, not deficiency.
Option B is incorrect because erythropoietin is not low; it is inappropriately normal,
indicating relative deficiency. Option D is incorrect because folate deficiency would present
with macrocytic anemia (elevated MCV), not microcytic anemia.
Page | 2
,2. A patient with a history of recurrent deep vein thrombosis (DVT) and pulmonary
embolism (PE) is found to have a prolonged activated partial thromboplastin time (aPTT)
that does not correct with mixing studies. Which of the following is the most likely
underlying cause?
A) Factor V Leiden mutation
B) Antiphospholipid syndrome (APS)
C) Protein C deficiency
D) Antithrombin III deficiency
Answer: B
Rationale: A prolonged aPTT that does not correct upon mixing with normal plasma
indicates the presence of an inhibitor, such as a lupus anticoagulant, which is characteristic
of antiphospholipid syndrome (APS). Despite the prolonged aPTT in vitro, APS is a
hypercoagulable state due to the antibody's interference with the protein C pathway and
increased tissue factor expression, leading to recurrent arterial and venous thromboses.
Factor V Leiden mutation (A) is associated with normal aPTT and causes activated protein
C resistance. Protein C deficiency (C) also presents with normal aPTT and is associated
with venous thromboembolism. Antithrombin III deficiency (D) typically does not prolong
aPTT; it reduces the inhibition of thrombin and factor Xa, leading to hypercoagulability.
The lack of correction in mixing studies is the key distinguishing feature pointing to an
inhibitor rather than a factor deficiency.
3. A patient with sickle cell disease (HbSS) develops acute chest syndrome after a vaso-
occlusive crisis. Which of the following pathophysiologic mechanisms contributes most
directly to the development of acute chest syndrome?
A) Increased nitric oxide production leading to vasodilation and pulmonary congestion
B) Intravascular hemolysis causing free hemoglobin scavenging of nitric oxide and
endothelial dysfunction
Page | 3
, C) Bone marrow embolism from necrotic bone marrow
D) Pulmonary vasospasm due to cold exposure
Answer: B
Rationale: Acute chest syndrome in sickle cell disease is a life-threatening complication
characterized by fever, respiratory symptoms, and new pulmonary infiltrates. The
pathogenesis is multifactorial, but intravascular hemolysis plays a central role. Free
hemoglobin released from lysed red blood cells scavenges nitric oxide (NO) with high
affinity, reducing NO bioavailability. This leads to endothelial dysfunction, increased
expression of adhesion molecules (VCAM-1, ICAM-1), and vasoconstriction. These changes
promote adhesion of sickled erythrocytes to the endothelium, further vaso-occlusion, and
ischemia-reperfusion injury in the pulmonary microvasculature. Option A is incorrect
because NO is decreased, not increased, in hemolytic states. Option C (bone marrow
embolism) is a less common mechanism and typically occurs in long bone infarcts, not as
the primary driver of acute chest syndrome. Option D is incorrect because cold exposure
triggers vaso-occlusive crises but is not the direct mechanism for acute chest syndrome.
4. A patient with chronic lymphocytic leukemia (CLL) develops autoimmune hemolytic
anemia (AIHA). Which of the following laboratory findings would most likely be present?
A) Elevated haptoglobin and normal LDH
B) Positive direct antiglobulin test (DAT) with anti-IgG and anti-C3d
C) Low reticulocyte count and elevated bilirubin
D) Schistocytes on peripheral smear and thrombocytopenia
Answer: B
Rationale: Autoimmune hemolytic anemia (AIHA) is a common complication of CLL,
occurring in approximately 10-15% of patients. The warm antibody type, mediated by IgG
Page | 4
