Deck 11: Sickle Cell Disease

Question 1

A 5-month-old African American boy presents to the ER for unexplained fever and swelling of his hands and feet. The mother states that 2 days ago when she was putting on his socks she noticed that his socks no longer fit, and he was extremely fussy and crying when touching both his feet. She states that at the end of day both of his feet had increased in size and appeared swollen. Yesterday morning while breastfeeding she noticed that his fingers appeared swollen and describes them as being "sausage like" and that he felt feverish. She measured his temperature that morning and it was 101.5 F, (temporal).
She denies any administration of medicine or antibiotics recently, or sick contacts. She states that their family just came back from a vacation in Colorado where they went skiing for the first time. Family history is negative except for a distant relative on the mother's side having a disease she describes "where his RBCs were shaped differently and would make him sick in colder weather". All newborn screening tests were negative.
You order a complete lab work-up and get back the CBC with differential results that show normocytic anemia, a low platelet count, target cells, and depranocytes also known as sickled cells. You suspect that your patient may have Sickle cell disease.
What test must you order is considered diagnostic for sickle cell disease?

A) Solubility test
B) Hemoglobin electrophoresis
C) Bone marrow biopsy
D) Flow cytometry

Answer 1

B
Explanation: The presence of large quantities of HbS using hemoglobin electrophoresis is considered diagnostic for sickle cell disease. Low platelet count, abdominal pain, nausea, and vomiting may also be present. This presentation occurs most frequently in young children with sickle cell disease and may include a febrile illness.

Question 2

A 25-year-old African American male is in the hospital recovering from a cholestectomy performed a day ago and is now complaining of priapism. He states that he noticed it around lunch time today and says that it has not gone down for the past couple hours. He mentions that he had a similar incident while visiting the Rocky Mountains on a skiing trip and went to the ER there and was told he had some kind of disease of the blood where his hemoglobin gene was defective.
You order a full lab-workup along with a solubility test to screen for HbS. CBC showed a normocytic anemia and solubility test was positive. The solubility test does not differentiate between sickle cell disease, sickle cell trait, and hemoglobin SC disease. You order a hemoglobin electrophoresis. The results of the electrophoresis will not be known for a couple days.
What lab results will show a notable differentiation between hemoglobin SS and hemoglobin SC disease?

A) Hemoglobin levels
B) Platelet count
C) Hematocrit
D) Iron levels

Answer 2

A
Explanation: Hemoglobin SC disease occurs in people who have one copy of the gene for sickle cell disease and one copy of the gene for hemoglobin C disease. Symptoms associated with HbSC disease are similar to sickle cell disease, but tend to be milder in some patients. A notable clinical differentiation between hemoglobin SS and hemoglobin SC disease is that SC patients tend to have higher hemoglobin levels (9-14 gm/dL) than SS patients (6.0 -9.0 gm/dL).

Question 3

What is the leading cause of death among adult patients who suffer from sickle cell disease?

A) Stroke
B) Myocardial infraction
C) Acute chest syndrome
D) Pulmonary hypertension

Answer 3

C
Explanation: The leading cause of death among adult patients with sickle cell disease is acute chest syndrome, although infection and fat emboli are also thought to play a role in bringing about this syndrome.

Question 4

You just newly diagnosed a male patient with Sickle cell disease and are counseling them on the effects the disease can have on their body if they are not properly treated. Which of the following complications is this patient at risk for?

A) Erectile dysfunction
B) Renal failure
C) Osteomyelitis
D) Ulcers in buccal mucosa

Question 5

A 30-year-old Caucasian male is at your office inquiring about what type of immunizations he will need regarding his trip to Africa next year for a missionary trip. The topic of Malaria comes up and he is concerned because he read that no antimalarial drug is 100% protective against being infected. Out of the following choices, what person would have a decreased risk of an infection by a malarial parasite?

A) A person who uses insect repellent and long pants.
B) A person who sleeps in an insecticide-treated bed net.
C) A person who on electrophoresis shows Hemoglobin S.
D) A person taking Chloroquine weekly while in an endemic area.

Question 6

A 2-day old female newborn recently underwent routine newborn screenings that are required for any infant born in the United States. You receive the results and notice that her screening test for Hemoglobin S was positive. By what age must the newborn be confirmed for having sickle cell disease or a significant hemoglobinopathy?

A) 1 week of age
B) 1 month of age
C) 6 weeks of age
D) 6 months of age

Question 7

Which of the following choices is a TRUE statement about the drug Hydroxyurea and its use in therapy for the sickle cell disease population?

A) It improves red blood cell survival by inducing production of fetal hemoglobin (HgF) that is resistant to sickling.
B) It increases the white blood cell count and arrests inflammatory processes.
C) It metabolizes into nitrogen oxide, which acts as a vasodilator to help improve blood flow.
D) It is the only curative treatment available for sickle cell disease.

Question 8

What is the only available curative treatment for Sickle cell disease?

A) Hydoxyurea
B) Red cell transfusions
C) Allogenic transplant
D) Chemotherapy

Question 9

You are counseling a newly diagnosed sickle cell disease patient on the importance of avoiding certain activities because they might lead to precipitating a sickle cell crisis exacerbation. Which of the following scenarios listed below will most likely NOT lead to a sickle cell crisis?

A) A person who undergoes an elective 6-hour Whipple procedure for pancreatic cancer.
B) A person running a marathon in 95-degree weather and does not hydrate throughout the race.
C) A person who indulges in a high purine, gluten, and dairy diet.
D) A person traveling from Florida to Colorado and staying a week in the mountains.

Question 10

A 55-year-old male with sickle cell disease, hyperlipidemia and hypertension is currently undergoing weekly red cell transfusions of sickle cell negative blood because of his high risk of stroke after experiencing a transient ischemic attack six months ago. It has been shown that transfusions can decrease a patient's risk of stroke or recurrent CVA. Conversely, repeated transfusions will result in iron overload, so iron and ferritin levels must be monitored closely. What test will provide the MOST accurate picture of total body iron burden in a patient undergoing multiple transfusions?

A) Liver CT scan
B) Iron and Ferritin levels
C) Liver Biopsy
D) Transferrin and total iron-binding capacity