Snapshot A 6-year-old boy presents to the hospital with a severe upper respiratory infection requiring hospitalization. Chart review reveals that he has presented multiple times to the emergency room and primary care physician’s office for a variety of infections, including otitis media, upper respiratory infections, pneumonia, and sinusitis. When detailing family history, it is found that his maternal uncle died of an infection as a child. Lab findings include decreased levels of IgG, IgM, and IgA. Introduction Primary humoral immunodeficiency characterized by decreased immunoglobulins Genetics X-linked recessive seen in male children Pathogenesis defect in Bruton tyrosine kinase (BTK) defective maturation of B-cells impaired signaling from pre-B-cell receptor ↓ B-cells ↓ production of all classes of Ig impaired antibody immune response Presentation Symptoms recurrent infections especially after 6 months old (↓ maternal IgG) Streptococcus pneumoniae, Hemophilus influenzae, Streptoccocus pyogenes, and Pseudomonas increased susceptibility to encapsulated bacteria and blood-borne viruses due to opsonization defect Physical exam absent/scant lymphoid tissues (tonsils/lymph nodes) Evaluation Diagnosis based on family history, clinical history, and exam Serologies ↓ all classes of Ig ↓ levels of B-cells normal T-cells Diagnosis confirmed with DNA, mRNA, or protein analysis showing mutation in BTK Differential Diagnosis Common variable immunodeficiency Severe combined immunodeficiency Transient hypogammaglobulinemia of infancy Treatment Antibiotics for infections Regular IVIG infusions Prognosis, Prevention, and Complications Prognosis normal prognosis with regular IVIG therapy and early detection Prevention screening in newborns regular IVIG to prevent infections Complications small risk of malignancy
QUESTIONS 1 of 8 1 2 3 4 5 6 7 8 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.IM.15.74) A father brings his 9-month-old child into the pediatrician's office because he is concerned about his child's health. He states that starting a few months ago, the child has had recurrent infections, with the most recent being a Giardial infection. On physical exam, the child is well-appearing but the pediatrician notes an absence of tonsils. Concerned for a possible immunodeficiency, the pediatrician obtains Ig levels which demonstrates decreased IgM, IgG, IgA, and IgE. Which of the following pedigrees best represents the mode of inheritance of this patient's condition? Tested Concept QID: 106663 FIGURES: A B C D E Type & Select Correct Answer 1 Figure A 7% (13/190) 2 Figure B 7% (14/190) 3 Figure C 12% (22/190) 4 Figure D 59% (113/190) 5 Figure E 13% (25/190) M 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (M1.IM.14.30) You are seeing a 4-year-old boy in clinic who is presenting with concern for a primary immune deficiency. He has an unremarkable birth history, but since the age of 6 months he has had recurrent otitis media, bacterial pneumonia, as well as two episodes of sinusitis, and four episodes of conjunctivitis. He has a maternal uncle who died from sepsis secondary to H. influenza pneumonia. If you drew blood work for diagnostic testing, which of the following would you expect to find? Tested Concept QID: 105700 Type & Select Correct Answer 1 Abnormally low number of B cells 75% (51/68) 2 Abnormally low number of T cells 15% (10/68) 3 Abnormally high number of B cells 1% (1/68) 4 Abnormally high number of T cells 6% (4/68) 5 Elevated immunoglobulin levels 1% (1/68) M 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept (M1.IM.13.57) A 7-month-old Caucasian male presents with recurrent sinusitis and pharyngitis. The parents say that the child has had these symptoms multiple times in the past couple of months and a throat swab sample reveals the presence of Streptoccocus pneumoniae. Upon workup for immunodeficiency it is noted that serum levels of immunoglobulins are extremely low but T-cell levels are normal. Which of the following molecules is present on the cells that this patient lacks? Tested Concept QID: 100478 Type & Select Correct Answer 1 CD4 17% (12/71) 2 CD8 6% (4/71) 3 CD3 7% (5/71) 4 CD19 62% (44/71) 5 NKG2D 3% (2/71) M 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (M1.IM.13.1) Which of the following patient presentations seen in a pediatric immunology clinic is most consistent with a diagnosis of Bruton's agammaglobulinemia? Tested Concept QID: 105399 Type & Select Correct Answer 1 A 15-month-old girl who has had repeated otitis media, pneumonia, and progressive clumsiness since beginning to walk in the past three months 4% (9/228) 2 A 10-month-old boy who has had recurrent viral infections as well as hypocalcemia during neonatal period 4% (10/228) 3 A 4-year-old girl who has had repeated oral candidasis in the past nine months 3% (6/228) 4 A 9-month-old boy who has had recurrent otitis media and pneumococcal pneumonia in the past three months 76% (173/228) 5 A 7-month-old boy who has had recurrent pneumococcal pneumonia, eczema, and easy bruising in the past four months 11% (26/228) M 2 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept