The Quizzes about Immunology – Part 1

A 7-month-old male infant presents to the emergency department with severe middle ear and upper respiratory tract infections, which respond promptly to antibiotics. Two months later he is again admitted, this time with Streptococcus pneumoniae pneumonia. After several more episodes of bacterial infections, genetic testing is done and the presence of a defective B-cell tyrosine kinase gene (btk gene or X-LA gene) is revealed. In addition, physical examination detects very small tonsils. Which of the following is the most likely diagnosis?

Flow cytometry of blood from an HIV-positive patient yielded a CD4:CD8 ratio less than 1. This ratio best represents a major decline in which of the following cell types and its associated cell surface proteins?

Flow cytometry of blood from an HIV-positive patient yielded a CD4:CD8 ratio less than 1. Which of the following best represents the “costimulatory signal” pair that occurs between cellular surface proteins associated with the reduced cell type represented in the CD4:CD8 ratio less than 1?

A young girl has had repeated infections with Candida albicans and respiratory viruses since she was 3 months old. As part of the clinical evaluation of her immune status, her responses to routine immunization procedures should be tested. In this evaluation, the use of which of the following vaccines is contraindicated?

A 7-year-old male developed normally until 7 years of age, after which he suddenly starts suffering from progressive personality and intellect deterioration leading to dementia, and finally death within 1 year of symptoms. His history reveals severe measles attack at the age of 1. Laboratory tests indicate elevated measles antibody levels in both the serum and cerebrospinal fluid (CSF) with no antibody to the M protein. A latent measles-like viral infection and, presumably, a defect in cellular immunity are associated with which of the following diseases?

A 31-year-old patient suffering from recurrent episodic intestinal hemorrhages attributed to a severe form of Crohn disease decides to undergo surgery to resect his terminal ileum. The surgeon orders two units of blood to be preserved for possible use during the surgery. The patient decides to store one unit of his own blood and one unit of his 35-year-old brother’s blood with the blood bank. This type of donation is most likely which of the following transplantation terminology (patient’s blood:brother’s blood)?

A 27-year-old female presents to the emergency room with a temperature of 103°F, severe fatigue, weight loss, and joint pain. During the history and physical examination, the patient reports that she stopped taking her aspirin and corticosteroids to control her condition. A butterflytype rash over her cheeks, sensitivity to light, and a heart murmur are apparent. The patient also reports a history of a progressively developing arthritis and glomerulonephritis. Laboratory tests further indicate anemia, leukopenia, and thrombocytopenia. This condition is best diagnosed by the presence of which of the following?

A 19-year-old college student develops a rash. She works part-time in a pediatric AIDS clinic. Her blood is drawn and tested for specific antibody to the chicken pox virus (varicella-zoster). Which of the following antibody classes would you expect to find if she is immune to chicken pox?

As part of the management of a 28-year-old male with acute onset of Crohn disease of the small bowel, you decide to treat him with a new cocktail of mouse–human chimeric antibodies to reduce his intestinal inflammation and cachexia. To which of the following sets of proteins are these antibodies directed?

A mother and newborn are exposed to a pathogen while at the hospital for a routine checkup and breastfeeding clinic. This same pathogen had infected the mother about a year previously, and she had successfully recovered from the subsequent illness. Immunity may be innate or acquired. Which of the following best describes acquired immunity with respect to the newborn?

A 35-year-old male patient presents with numerous subcutaneous hemorrhages. History and physical examination reveal that he has been taking sedormid (a sedative) for the past week. Laboratory tests indicate normal hemoglobin and white blood cell levels with significant thrombocytopenia (very low platelet count). You suspect that he has developed a drug-induced type II hypersensitivity reaction. This reaction may occur if the drug does which of the following?

After learning of a family history of humoral immunity deficiency during an office visit from a patient 6 months pregnant, a radial immunodiffusion assay is ordered on fetal serum. The test reveals no humoral immunity problems and normal results in all respects. According to this test, the normal level of which fetally made immunoglobulin is the highest in the fetus?

A 31-year-old male patient complains of fatigue, yeast infection in his mouth, and enlarged lymph nodes under his arms. He says that he was involved in “high-risk” behavior 6 years ago while on a trip to eastern and southern Africa. He also indicates that his “HIV test” was negative. Which of the following options is most appropriate?

A laboratory analysis report of a specific fraction of a patient’s lymphocytes indicates the following: HLA, B, and C+, PHA+, CD3–, CD16+, CD11a/CD18+, CD56+, and in vitro blastogenesis with IL-12. What are the lymphocytes that this set describes?

The complement system plays a key role in the host defense process. Which of the following components of this system is the most important in chemotaxis?

Soon after birth, a newborn undergoes heart transplantation surgery at a local medical center. Transplantation of tissue and organs is a common procedure whose success depends largely on the “self” versus “nonself” interactions. Survival of allografts is increased by choosing donors with few major histocompatibility complex (MHC) mismatches compared to recipients and by use of immunosuppression in recipients. Which of the following procedures is the most useful measure of immunosuppression in recipients?

Relative to the primary immunological response, secondary, and later booster responses to a given hapten–protein complex can be associated with which one of the following?

Of the five immunoglobulin classes, IgA is the main immunoglobulin of secretions from the genital, respiratory, and intestinal tracts. As a result, IgA antibody is the first line of defense against infections at the mucous membrane. It is usually an early specific antibody. Which of the following statements most accurately describes IgA?

A 60-year-old male presents with severe jaundice to the local walk-in clinic. History and physical examination reveal a 30-year history of alcohol consumption and drug abuse. Blood tests reveal elevated AST and ALT levels and the presence of hepatitis B and, as a result, reduced complement levels. Complement is a series of important host proteins that provide protection from invasion by foreign microorganisms. Which of the following best describes complement?