A 28-year-old female named Ava complains to her family physician of abdominal pain, loss of appetite, and low-grade fever. Physical examination reveals abdominal tenderness and a low-grade fever. Her physician orders a hepatitis profile and obtains the results below.

Anti-HAV: Nonreactive

Anti-HBc: Reactive

Anti-HBs: Nonreactive

HBsAg: Reactive

HBeAg: Reactive

Anti-HCV: Nonreactive

Which of the following is the most likely conclusion?

In a chemiluminescent immunologic assay conducted by Sophia in her lab, what is the signal detected?

Grace is studying the effects of vaccination against hepatitis B virus (HBV) and learns that it also prevents hepatitis D virus (HDV) infections. Why is this the case?

Sophia learned in her biology class that B lymphocytes and T lymphocytes are derived from

Ava went to the doctor for an allergy test, and the doctor performed a competitive radioimmunosorbent test (RIST). What does a high signal suggest in her test results?

Ava developed a rash after using a new skincare product. Her doctor explained that contact dermatitis is mediated by

In a health clinic, Michael, who is living with human immunodeficiency virus infection, is being monitored for his immune status. The healthcare provider decides to measure the ratio of

In a biology class, Benjamin is learning about the immune system. He discovers that cells that can act as antigen-presenting cells for exogenous antigens include

A living donor is being sought for a child named Ethan who requires a kidney transplant. The best odds of finding an MHC-compatible donor occur between Ethan and

During a routine health check-up, Mason learns that he has been exposed to the hepatitis B virus. The doctor explains that the first serologic marker to appear in patients with acute hepatitis B virus infection is

During a biology class, Abigail learned about "Superantigens" which are toxins produced by some strains of Staphylococcus aureus and group A streptococci. Her teacher explained that these toxins cause damage by

Noah recently recovered from a group A streptococcal infection. However, he later developed rheumatic fever, which caused an autoimmune response that attacked the tissue of his heart valves. This phenomenon is an example of

During a health class, Anika learned about various autoimmune diseases. One disease that caught her attention was Hashimoto disease, which primarily involves the

Evelyn, a medical student, is conducting an experiment where patient serum is mixed with a suspension of guinea pig antigen. When the sample is then mixed with horse red blood cells, agglutination occurs. This is suggestive of an infection caused by

Michael visited his doctor after experiencing fatigue and joint pain. A patient report states the presence of serum antibodies to OspC. What disease does Michael most likely have?

During a biology class, Liam learned that the isotype of an immunoglobulin antibody

During a laboratory class, Daniel was learning about various diagnostic tests. He came across the complement fixation test and wondered what indicator system is used in this test.

Hannah's serum sample is positive for HBsAg.

This result indicates that the person from whom the serum was taken

During a health screening event at the university, William is asked to identify which of the following is an example of a treponemal antigen test used for the diagnosis of syphilis?

During a science experiment, Rohan mixed a soluble antigen with a soluble antibody, and they reacted to form an insoluble product. This process describes

During a blood transfusion, Samuel received blood from a donor with a different blood type, leading to a severe reaction. This incident is an example of

Abigail gets a cut on her finger while playing outside, and it becomes contaminated with the bacterium Staphylococcus aureus. The first response by the immune system consists of activity of

During a biology class, Abigail learned about the alternative complement pathway in the immune system.

During a biology lab, Zoe learned about the classical pathway of complement activation,

Aiden went to the doctor for a routine check-up. The doctor decided to test for C-reactive protein (CRP) to assess Aiden's health. Which of the following statements about the test for C-reactive protein (CRP) is true?

During a biology class, Charlotte developed a rash after touching a plant that she was allergic to. Which of the following is characteristic of contact hypersensitivity reactions?

During a biology lab, Abigail and her classmates were discussing the components of the immune system. Luna asked, "Which of the following complement proteins is part of the membrane attack complex?"

James, a 10-year-old boy, was diagnosed with an autoimmune disease that is causing destruction of his pancreatic cells. His doctor explained that this condition can result in

During a biology lab, Isla and Noah were discussing the various complement proteins found in human serum. Noah asked, "Which complement protein is present in the greatest concentration in human serum?"

During a class discussion on autoimmune diseases, Aria asked her classmates about the primary mechanism responsible for pathology in systemic lupus erythematosus.

Ava is studying the immune system in her biology class. Her teacher asks the class, "Which of the following is a characteristic of T cells?"

In a biology class, Isla and Priya are discussing how B and T helper cells interact in the immune system. They wonder about the specific mechanisms involved in this interaction.

Lily learned about the activity of natural killer (NK) cells in her biology class.

During a health class, Zoe learns about various diagnostic tools used in medicine. One topic that comes up is skin testing, which is particularly useful in diagnosing disorders like tuberculosis. Which of the following statements about skin testing is true?

During a biology lab, Grace and Abigail were discussing antibodies. Grace mentioned that antibodies that bind to the same epitope are of the same

In a laboratory, Zoe is learning about how monoclonal antibodies are produced. She discovers that these antibodies are created by

In a biology class, Aria is explaining the structure of an immunoglobulin molecule to her classmates. She mentions, "Which of the following statements applies to the Fc fragment of an immunoglobulin molecule?"

During a biology class, Aria learned about immunoglobulin light chains. Which of the following statements about immunoglobulin light chains is true?

In a biology class, Ethan is learning about human cells and their functions. He discovers that a human cell with CDS on its surface is most likely a

During a biology class, Benjamin learned that loss of self-tolerance results in

During a recent health fair, Luna learned that elevated IgE levels are typically found in certain types of allergic reactions. She was curious about which type of hypersensitivity reaction is associated with high IgE levels.

During a science fair, Jackson is demonstrating the enzyme-linked immunosorbent assay (ELISA) technique. He explains that the visible reaction in his experiment is due to a reaction between

During a biology class, Maya learned about antibodies and their structure. She discovered that the Fab portion of an antibody

Ava is feeling unwell and visits her doctor. The doctor decides to perform a serologic test to check for autoimmune disorders using an immunofluorescence method. Which of the following tests is the doctor likely to perform?

During a recent biology lab, Hannah learned that IgM antibodies react well in complement fixation (CF) tests. Because of this, CF tests for antibodies should

During a science fair, Anika presented her project on antibodies. She explained that identical antibodies produced from a single clone of plasma cells describes a specific type of antibody. What type of antibody is she referring to?

During a biology class, Benjamin learned that the portion of an antigen that binds to an antibody or T cell receptor is called a(n)

During a routine health check, Scarlett received a false-positive result on her VDRL test. One possible cause of this false-positive result is

During a health class, Henry learned about various tests for sexually transmitted infections. He discovered that the Venereal Disease Research Laboratory (VDRL) test for syphilis is classified as a(n)

The rapid plasma reagin assay for syphilis does not need to be read microscopically because the antigen is

The antibody most frequently present in systemic lupus erythematosus is directed against

Innate immunity includes

The type of immunity that follows the injection of antibodies synthesized by another individual or animal is termed

The type of immunity that follows the injection of an immunogen is termed

After activation of the complement system, leukocytes and macrophages are attracted to the site of complement activation by

How does the secondary humoral immune response differ from the primary response?

The strength with which a multivalent antibody binds a multivalent antigen is termed the

A major advantage of passive immunization compared to active immunization is that

Diagnostic reagents useful for detecting antigen by the coagglutination reaction may be prepared by binding antibody to killed staphylococcal cells via the Fc receptor of staphylococcal protein A. The class of antibody bound by this protein is

Which cell is the principal source of interleukin 2?

A molecule found in human serum sometimes used as a tumor marker is

Diagnosis of group A streptococci (Streptococcus pyogenes) infection is indicated by the presence of

In Bruton disease, measurement of serum immunoglobulins would show

A kidney transplant from one identical twin to another is an example of a(n)

After exposure to antigen, the first antibodies that can be detected belong to the class

Corneal tissue may be transplanted successfully from one patient to another because

Which one of the following describes a direct immunofluorescence assay?

In individuals allergic to pollen, hyposensitization protocols may be initiated. These individuals receive injections of

Multiple myeloma is a

In bone marrow transplantation, immunocompetent cells in the donor marrow may recognize antigens in the recipient and respond to those antigens. This phenomenon is an example of

The serologically detectable antibody produced in rheumatoid arthritis (RA) is primarily of the class

Severe combined immunodeficiency (SCID) is an

An example of immune injury due to the deposition of antigen-antibody complexes is

Which class of immunoglobulin binds to basophils and mast cells to mediate immediate hypersensitivity reactions?

Type I hypersensitivity is

The HLA complex is located primarily on

In primary biliary cirrhosis, which of the following antibodies is seen in high titers?

The simplest test to evaluate the cellular immune system in a patient is a(n):

In assessing the usefulness of a new laboratory test, sensitivity is defined as the percentage of:

The specificity of an immunoassay is determined by the:

Which test has the greatest sensitivity for antigen detection?

A monoclonal spike of IgG, Bence Jones proteinuria, and bone pain are usually associated with:

Which of the following fungal agents is a frequent complication of AIDS?

The most sensitive procedure for detection of hepatitis B surface antigen (HBsAg) is:

The serologic test that can be modified to selectively detect only specific IgM antibody in untreated serum is:

HLA-B8 antigen has been associated with which of the following pairs of diseases?

Which of the following is considered to be a non-suppurative complication of streptococcal infection

M. pneumoniae infections are associated with which antibodies?

Which of the following best describes the principle of the IFA test for detection of antibodies produced in Rocky Mountain spotted fever?

An individual with hepatomegaly, jaundice, and elevated liver enzymes has the following laboratory results: IgM anti-HAV (negative), HBsAg (positive), IgM anti-HBc (positive), and anti-HCV (negative). These findings support a diagnosis of

Which of the following hepatitis viruses is transmitted by the fecal-oral route?

Quantitative tests for HCV RNA are used to

The serum of an individual who received all doses of the hepatitis B vaccine should contain

The most common cause of congenital infections is

In the laboratory, heterophile antibodies are routinely detected by their reaction with

All of the following apply to HIV except

Antibodies to which of the following viral antigens are usually the first to be detected in HIV infection?

Which of the following genes is responsible for the coding of reverse transcriptase

Which of the following is typical of the latent stage of HIV infection?

The decrease in T-cell numbers in HIV-infected individuals is due to

Which of the following combinations of bands would represent a positive Western blot for HIV antibody?

All of the following are likely immunologic manifestations of HIV infection except

The RT-PCR is a highly sensitive method that involves

The most common means of HIV transmission worldwide is through