red blood cell and bleeding disorder

A 22-year-old woman has experienced malaise and a sore throat for 2 weeks. Her fingers turn white on exposure to cold. On physical examination, she has a temperature of 37.8°C, and the pharynx is erythematous. Laboratory findings include a positive Monospot test result. Direct and indirect Coombs test results are positive at 4°C, although not at 37°C. Which of the following substances on the surfaces of the RBCs most likely accounts for these findings?
□ (A) IgE
□ (B) Complement C3b
□ (C) Histamine
□ (D) IgG
□ (E) Fibronectin
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A 22-year-old woman has experienced malaise and a sore throat for 2 weeks. Her fingers turn white on exposure to cold. On physical examination, she has a temperature of 37.8°C, and the pharynx is erythematous. Laboratory findings include a positive Monospot test result. Direct and indirect Coombs test results are positive at 4°C, although not at 37°C. Which of the following substances on the surfaces of the RBCs most likely accounts for these findings?
□ (A) IgE
□ (B) Complement C3b
□ (C) Histamine
□ (D) IgG
□ (E) Fibronectin
B
A 30-year-old woman has had a constant feeling of lethargy since childhood. On physical examination, she is afebrile and has a pulse of 80/min, respirations of 15/min, and blood pressure of 110/70 mm Hg. The spleen tip is palpable, but there is no abdominal pain or tenderness. Laboratory studies show hemoglobin of 11.7 g/dL, platelet count of 159,000/mm3, and WBC count of 5390/mm3.The peripheral blood smear shows spherocytosis. The circulating RBCs show an increased osmotic fragility. An inherited abnormality in which of the following RBC components best accounts for these findings?
□ (A) Glucose-6-phosphate dehydrogenase
□ (B) Membrane cytoskeletal protein
□ (C) α-Globin chain
□ (D) Heme
□ (E) β-Globin chain
□ (F) Carbonic anhydrase
B
A 65-year-old man diagnosed with follicular non-Hodgkin's lymphoma is treated with chemotherapy. He develops fever and cough. On examination, there are bilateral pulmonary rales. A chest radiograph shows diffuse interstitial infiltrates. A shell vial assay of sputum is positive for cytomegalovirus. He develops scleral icterus. Laboratory studies show hemoglobin, 10.3 g/dL; hematocrit, 41.3%; MCV, 101 µm3; WBC count, 7600/mm
3; and platelet count, 205,000/mm3. His serum total bilirubin is 6 mg/dL, direct bilirubin is 0.8 mg/dL, and LDH is 1020 U/L. Coombs's test is positive. Which of the
following is the most likely mechanism for his anemia?
□ (A) Binding of IgM to red blood cells
□ (B) Chemotherapeutic bone marrow toxicity
□ (C) Cytomegalovirus hepatitis
□ (D) Dietary folate deficiency
□ (E) Metastases to colon
A
A 60-year-old man has developed widespread ecchymoses over the skin in the past month. His medical history includes a diagnosis of mucinous adenocarcinoma of the rectum. On physical examination, he appears cachectic and pale. An abdominal CT scan shows multiple hepatic masses. Laboratory studies show prothrombin time of 30 seconds, partial thromboplastin time of 55 seconds, platelet count of 15,200/mm3, and fibrinogen level of 75 mg/dL, and fibrin split product levels (D dimer) that are very elevated. Which of the following morphologic findings is most likely to be present on examination of his peripheral blood smear?
□ (A) Howell-Jolly bodies
□ (B) Teardrop cells
□ (C) Macro-ovalocytes
□ (D) Schistocytes
□ (E) Target cells
D
A 23-year-old woman has had a history of bleeding problems all of her life, primarily heavy menstruation and bleeding gums. A sister and an uncle also have bleeding problems. Physical examination shows several bruises ranging in color from red to blue to purple on her arms and legs. There is no organomegaly, and no deformities are noted. Laboratory studies show hemoglobin, 9.5 g/dL; hematocrit, 28.2%; platelet count, 229,300/mm3; WBC count, 7185/mm3; prothrombin
time, 12 seconds; and partial thromboplastin time, 38 seconds. A 1 : 1 dilution of the patient's plasma with normal pooledplasma corrects the partial thromboplastin time. Ristocetin-dependent platelet aggregation in patient plasma is markedly reduced. Factor VIII activity is 30% (reference range 50% to 150%). Which of the following responses should the physician use when advising the patient of potential consequences of this disease?
□ (A) You might need allogeneic bone marrow transplantation
□ (B) Expect increasing difficulty with joint mobility
□ (C) Anticoagulation is needed to prevent deep venous thrombosis
□ (D) You could experience excessive bleeding after oral surgery
□ (E) A splenectomy might be necessary to control the disease
D
A 12-year-old boy has a history of episodes of severe abdominal and back pain since early childhood. On physical examination, he is afebrile, and there is no organomegaly. Laboratory studies show hemoglobin of 11.2 g/dL, platelet count of 194,000/mm3, and WBC count of 9020/mm3. The peripheral blood smear shows occasional sickled cells, nucleated RBCs, and Howell-Jolly bodies. Hemoglobin electrophoresis shows 1% hemoglobin A2, 6% hemoglobin F, and 93% hemoglobin S. Hydroxyurea therapy is found to be beneficial in this patient. Which of the following is the most likely basis for its therapeutic efficacy?
□ (A) Increase in production of hemoglobin F
□ (B) Increase in production of hemoglobin A
□ (C) Decrease in overall globin synthesis
□ (D) Stimulation of erythrocyte production
□ (E) Increase in oxygen affinity of hemoglobin
A
A 50-year-old man has experienced chronic fatigue and weight loss for the past 3 months. There are no remarkable findings on physical examination. Laboratory studies show hemoglobin, 11.2 g/dL; hematocrit, 33.3%; MCV, 91 µm3; platelet count, 240,000/mm3; WBC count, 7550/mm3; serum iron 80 µg/dL; total iron-binding capacity, 145 µg/dL; and serum ferritin, 565 ng/mL. The ANA test result is positive. Which of the following is the most likely diagnosis?
□ (A) Iron deficiency anemia
□ (B) Aplastic anemia
□ (C) Anemia of chronic disease
□ (D) Microangiopathic hemolytic anemia
□ (E) Megaloblastic anemia
□ (F) Thalassemia minor
C
A 12-year-old boy experienced sudden onset of severe abdominal pain and cramping accompanied by chest pain, nonproductive cough, and fever. On physical examination, his temperature is 39°C, pulse is 110/min, respirations are 22/min, and blood pressure is 80/50 mm Hg. He has diffuse abdominal tenderness, but no masses or organomegaly. Laboratory studies show a hematocrit of 18%. The peripheral blood smear is shown in the figure. A chest x-ray shows bilateral pulmonary infiltrates. Which of the following is the most likely mechanism for initiation of his pulmonary problems?
□ (A) Intravascular hemolysis
□ (B) Chronic hypoxia of the pulmonary parenchyma
□ (C) Increased RBC adhesion to endothelium
□ (D) Defects in the alternative pathway of complement activation
□ (E) Formation of autoantibodies to alveolar basement membrane
C
A 32-year-old woman from Saigon, Vietnam, gives birth at 34 weeks' gestation to a markedly hydropic stillborn male
infant. Autopsy findings include hepatosplenomegaly and cardiomegaly, serous effusions in all body cavities, andgeneralized hydrops. No congenital anomalies are noted. There is marked extramedullary hematopoiesis in visceral organs. Which of the following findings is most likely to be present on hemoglobin electrophoresis of the fetal RBCs?
□ (A) Hemoglobin A1
□ (B) Hemoglobin A2
□ (C) Hemoglobin Bart's
□ (D) Hemoglobin
□ (E) Hemoglobin E
□ (F) Hemoglobin F
□ (G) Hemoglobin H
□ (H) Hemoglobin S
C
A 17-year-old boy reports passage of dark urine to his physician. He has a history of multiple bacterial infections and venous thromboses for the past 10 years, including portal vein thrombosis in the previous year. On physical examination, his right leg is swollen and tender. CBC shows hemoglobin, 9.8 g/dL; hematocrit, 29.9%; MCV, 92 µm3; platelet count,150,000/mm3; and WBC count, 3800/mm3 with 24% segmented neutrophils, 1% bands, 64% lymphocytes, 10% monocytes, and 1% eosinophils. He has a reticulocytosis, and his serum haptoglobin level is very low. A mutation affecting
which of the following gene products is most likely to give rise to this clinical condition?
□ (A) Spectrin
□ (B) Glucose-6-phosphate dehydrogenase
□ (C) Phosphatidylinositol glycan A (PIGA)
□ (D) β-Globin chain
□ (E) Factor V
□ (F) Prothrombin G20210A
C
A 32-year-old man has reported easy fatigability since childhood. On physical examination, he is normally developed and is afebrile. Laboratory studies show hemoglobin of 8.8 g/dL, hematocrit of 26.3%, platelet count of 199,000/mm3, andWBC count of 5350/mm3. α-Globin inclusions are present in erythroblasts and erythrocytes, leading to increased phagocytosis by cells of the mononuclear phagocyte system. Hemoglobin electrophoresis shows hemoglobin A2 of 6%, hemoglobin F of 1%, and hemoglobin A1 of 93%. The serum ferritin level is 3090 ng/mL. Which of the following is the most likely diagnosis? □ (A) Autoimmune hemolytic anemia □ (B) Glucose-6-phosphate dehydrogenase deficiency □ (C) Megaloblastic anemia □ (D) β-Thalassemia □ (E) Sickle cell anemia □ (F) Paroxysmal nocturnal hemoglobinuriaDA 16-year-old girl has a history of easy bruising and hemorrhages. Since menarche at the age of 14 years, she has had menometrorrhagia. On physical examination, she displays joint deformity and has decreased mobility of the ankles, knees, and wrists. Laboratory studies show hemoglobin, 11.8 g/dL; hematocrit, 35.1%; platelet count, 267,000/mm3; WBC count,5960/mm3; prothrombin time, 13 seconds; and partial thromboplastin time, 60 seconds. A 1 : 1 dilution of the patient's plasma with normal pooled plasma corrects the partial thromboplastin time. Which of the following is the most likely diagnosis? □ (A) Antiphospholipid syndrome □ (B) Disseminated intravascular coagulation □ (C) Hemophilia A □ (D) Idiopathic thrombocytopenic purpura □ (E) Thrombotic thrombocytopenic purpura □ (F) Vitamin K deficiency □ (G) Von Willebrand diseaseCA 3-year-old boy of Italian ancestry is brought to the physician because he has a poor appetite and is underweight for his age and height. Physical examination shows hepatosplenomegaly. The hemoglobin concentration is 6 g/dL, and the peripheral blood smear shows severely hypochromic and microcytic RBCs. The total serum iron level is normal, and the reticulocyte count is 10%. A radiograph of the skull shows maxillofacial deformities and an expanded marrow space. Which of the following is the most likely principal cause of this child's illness? □ (A) Reduced synthesis of hemoglobin F □ (B) Imbalance in production of α-globin and β-globin chains □ (C) Sequestration of iron in reticuloendothelial cells □ (D) Increased fragility of erythrocyte membrane □ (E) Relative deficiency of vitamin B 12BA 28-year-old, previously healthy man has noted increasing fatigue for the past 6 months and formation of bruises after minimal trauma. Over the past 2 days, he has developed a cough. On physical examination, his temperature is 38.9°C, and he has diffuse rales in both lungs. He has no hepatosplenomegaly and no lymphadenopathy. Laboratory findings Include a sputum culture positive for Streptococcus pneumoniae, hemoglobin of 7.2 g/dL, hematocrit of 21.7%, platelet count of 23,400/mm3, WBC count of 1310/mm3, prothrombin time of 13 seconds, partial thromboplastin time of 28 seconds, and total bilirubin of 1 mg/dL. The ANA test result is negative. What is the most likely explanation of these findings? □ (A) Hemolysis of antibody-coated cells □ (B) Hypersplenism □ (C) Increased susceptibility to lysis by complement □ (D) Metastatic adenocarcinoma □ (E) Nuclear maturation defects resulting from impaired DNA synthesis □ (F) Stem cell defect □ (G) Varicella-zoster virus infectionFA 55-year-old, otherwise healthy man has experienced minor fatigue on exertion for the past 9 months. He has no significant previous medical or surgical history. On physical examination, there are no remarkable findings. Laboratory studies show hemoglobin of 11.7 g/dL, hematocrit of 34.8%, MCV of 73 µm3, platelet count of 315,000/mm3, and WBC count of 8035/mm3 . Which of the following is the most sensitive and cost-effective test that the physician should order to help to determine the cause of these findings? □ (A) Serum iron □ (B) Serum transferrin □ (C) Serum haptoglobin □ (D) Bone marrow biopsy □ (E) Serum ferritin □ (F) Hemoglobin electrophoresisEA 26-year-old woman has experienced chronic fatigue since early childhood. She also has had episodes of severe pain in the abdomen, back, and legs. On physical examination, there is no organomegaly. Laboratory studies show hemoglobin, 8.9 g/dL; hematocrit, 26.9%; platelet count, 300,100/mm3; and WBC count, 5560/mm3. Hemoglobin electrophoresis shows1% hemoglobin A2 , 6% hemoglobin F, and 93% hemoglobin S. Which of the following is this patient most likely to develop as a complication of the underlying disease? □ (A) Micronodular cirrhosis □ (B) Chronic atrophic gastritis □ (C) Pigment gallstones □ (D) High rate of stillbirths □ (E) Esophageal webCA 9-year-old boy has developed prominent bruises on his extremities over the past week. On physical examination, he has ecchymoses and petechiae on his arms and legs. Laboratory studies show hemoglobin, 13.8 g/dL; hematocrit, 41.9%; MCV, 93 µm3; platelet count, 22,300/mm3; and WBC count, 7720/mm3. He had respiratory syncytial virus pneumonia 3 weeks ago. His condition improves with corticosteroid therapy. Which of the following abnormalities is most likely to cause his hemorrhagic diathesis? □ (A) Antiplatelet antibodies □ (B) Bone marrow aplasia □ (C) Glycoprotein IIb/IIIa dysfunction □ (D) Vitamin C deficiency □ (E) Von Willebrand factor metalloproteinase deficiencyAA 77-year-old man has experienced increasing malaise and a 6-kg weight loss over the past year. He has noted more severe and constant back pain for the past 3 months. On physical examination, his temperature is 38.7°C. His prostate is firm and irregular when palpated on digital rectal examination. There is no organomegaly. A stool sample is negative for occult blood. Laboratory studies include a urine culture positive for Escherichia coli, serum glucose of 70 mg/dL, creatinine of 1.1 mg/dL, total bilirubin of 1 mg/dL, alkaline phosphatase of 293 U/L, calcium of 10.3 mg/dL, phosphorus of 2.6 mg/dL, and PSA of 25 ng/mL. CBC shows hemoglobin, 9.1 g/dL; hematocrit, 27.3%; MCV, 94 µm3; platelet count, 55,600/mm3; and WBC count, 3570/mm3 with 18% segmented neutrophils, 7% bands, 2% metamyelocytes, 1%, myelocytes, 61% lymphocytes, 11% monocytes, and 3 nucleated RBCs per 100 WBCs. What is the most likely diagnosis? □ (A) Anemia of chronic disease □ (B) Aplastic anemia □ (C) Hemolytic anemia □ (D) Megaloblastic anemia □ (E) Myelophthisic anemia □ (F) ThalassemiaEA 21-year-old woman known to have a protein C deficiency develops recurrent pulmonary thromboembolism and is placed on anticoagulant therapy. Two weeks after initiation of this therapy, she has a sudden change in mental status and experiences difficulty speaking and swallowing. A cerebral angiogram shows a distal left middle cerebral artery occlusion. Laboratory studies show hemoglobin of 13 g/dL, platelet count of 65,400/mm3, WBC count of 5924/mm3, prothrombin time of 12 seconds, and partial thromboplastin time of 51 seconds. The anticoagulant therapy is discontinued. Which of the following pharmacologic agents used as an anticoagulant in this patient is most likely to have caused these findings? □ (A) Acetylsalicylic acid (aspirin) □ (B) Warfarin □ (C) Heparin □ (D) Tissue plasminogen activator □ (E) UrokinaseCA 45-year-old woman has experienced episodes of blurred vision and headaches for the past 6 months. She has had worsening confusion with paresthesias over the past 3 days. On physical examination, she has a temperature of 39.6°C, pulse of 100/min, respiratory rate of 20/min, and blood pressure of 80/50 mm Hg. Petechial hemorrhages are noted over her trunk and extremities. Laboratory findings include hemoglobin, 10.9 g/dL; hematocrit, 34%; MCV, 96/min3; platelet count, 28,000/mm3; and WBC count, 8500/mm3. Fragmented RBCs are noted on her peripheral blood smear. Blood urea nitrogen is 40 mg/dL, and serum creatinine is 3.1 mg/dL. Which of the following is the most likely underlying cause for her findings? □ (A) Defective ADP-induced platelet aggregation □ (B) Presence of antibodies against von Willebrand's factor metalloproteinase □ (C) Formation of auto-antibodies to platelet glycoproteins IIb/IIIa and Ib-IX □ (D) Circulating toxin that injures capillary endothelium □ (E) Inappropriate release of thromboplastic substances into blood □ (F) Decreased factor VIII activityBA clinical study is performed using patients diagnosed with peptic ulcer disease, chronic blood loss, and hypochromic microcytic anemia. Their serum ferritin levels average 5 to 7 µg/mL. The rate of duodenal iron absorption in this study group is found to be much higher than in a normal control group. After treatment with omeprazole and clarithromycin, study group patients have hematocrits of 40% to 42%, MCV of 82 to 85 µm3, and serum ferritin of less than 12 µg/mL. Measured rates of iron absorption in the study group after therapy are now decreased to the range of the normal controls. Which of the following substances derived from liver is most likely to have been increased in the study group patients before therapy, returning to normal after therapy? □ (A) Transferrin □ (B) Hemosiderin □ (C) Hepcidin □ (D) Divalent metal transporter-1 (DMT-1) □ (E) HLA-like transmembrane proteinC