Case Study

Case 1
14-year-old female had missed several days of school in the spring with cold symptoms (head congestion and cough). She received antibiotics on two separate occasions but she seemed to get one cold after another. A complete blood count showed no overall increase in WBC’s, but mild eosinophilia was present. Because he had no fever or other signs of infection, his physician suggested that allergy testing be run.
1. What would account for the eosinophilia?
2. What tests should be run for this patient?
3. If the patient was treated with allergy immunotherapy, what test could be used to monitor his response over time?
Case 2
A 55-year-old male went to his physician complaining of feeling tired and run down. Two months previously, he had pneumonia and was concerned that he might not have completely recovered. He indicated that his symptoms only become noticeable if he goes out in the cold. A CBC was performed, showing that his WBC count was normal, his RBC count was just below normal. A DAT performed on RBC’s was weakly positive after incubating at room temperature for 5 minutes. When the DAT was repeated with monospecific reagents, the tube with anti-C3d was the only one positive.
1. What does a positive DAT indicate?
2. Why was the DAT positive with anti-C3d when monospecific reagents were used?
Case 3
A 63-year-old male visits his primary care physician complaining of fatigue and shortness of breath, upper back pain, and a cough that has become productive the last 2 days. The patient was febrile and appeared acutely ill. A chest x-ray revealed pneumonia and the following significant laboratory results were found. RBC, WBC, and hemoglobin are normal. A erythrocyte sedimentation rate was slightly elevated. Based on the results, the physician ordered serum immunoglobulin levels. The following results were reported: IgG 3,250 mg/dL (ref. range = 600 to 1,500 mg/dL), IgM 48 mg/dL (ref. range 75 to 150 mg/dL), and IgA 102 mg/dL (ref. range 150 to 250 mg/dL).
1. What disease(s) should you suspect? Why?
2. What additional tests could help confirm the diagnosis and what results would you expect to find?
Case 4
After recovering from a previous viral infection, a 7 year old was complaining of being tired all the time. He was just not himself, and began laying down often. His mother took him to his primary care physician where they found his hemoglobin to be 6.5g/dL. Upon pretransfusion work up, the antibody screen and autocontrol were positive, eventually determined to be due to an autoantibody P.
1. What condition is most likely present?
2. What is the classic test used to diagnose this?
3. Explain the characteristics of autoanti-P?
Case 5
A 23-year-old female visited her primary care physician complaining of blurry vision, numbness, and pain in her legs. After doing an extensive panel of laboratory testing, the physician ordered a MRI that revealed brain lesions. The below image is the patient’s CSF and plasma protein electrophoresis.

1. What is the most likely cause of the patient’s symptoms?
2. Why were the CSF and plasma analyzed together?
3. What is the name of the antibody that is most likely present and what time of antibody is it?