Question 1

Cold autoimmune hemolytic anemias are usually due to autoantibodies directed against a high frequency Rh antigen on the patient's cells.

Accepted Answer

Cold autoimmune hemolytic anemias are typically caused by autoantibodies that react at cold temperatures, usually IgM, and are directed against the I/i antigens on the red blood cells, not a high frequency Rh antigen.

Question 2

What neutrophil function is defective in leukocyte adhesion defect?

Accepted Answer

In leukocyte adhesion defect, the neutrophils are unable to adhere to the blood vessel walls, which impairs their ability to exit the bloodstream and enter tissues where they are needed to fight infections. This process is known as diapedesis.

Question 3

Patients who present with long bleeding times, easy bruising, and purpura should be evaluated for ________antibodies.

Accepted Answer

The answer of Patients who present with long bleeding times,...

Question 4

Plasma that contains antiphospholipids has prolonged clotting times in test tube assays. However, many patients with these antibodies experience an increased tendency to form blood clots.

Accepted Answer

Antiphospholipid antibodies interfere with the phospholipids involved in the clotting process, leading to prolonged clotting times in vitro. However, paradoxically, in vivo, they increase the risk of clot formation, contributing to conditions like antiphospholipid syndrome.

Question 5

Which of the following indicate that an HIV positive person has progressed into full blown AIDS?

Accepted Answer

All of the options listed are indicators of the progression from HIV positive status to AIDS. Kaposi's sarcoma and Pneumocystis carnii pneumonia are opportunistic infections associated with AIDS. A CD4 count below 200 cells/mm3 is a clinical marker for AIDS, and skin anergy to recall antigens indicates a weakened immune response, which is characteristic of AIDS.

Question 6

Autoantibodies are always damaging to host tissue.

Accepted Answer

Autoantibodies can be damaging and lead to autoimmune diseases, but not all autoantibodies cause harm. Some are naturally occurring and do not lead to tissue damage or clinical symptoms.

Question 7

Systemic lupus erythematosus (SLE)patients who have a false positive syphilis test probably have circulating anticardiolipin antibody.

Accepted Answer

Patients with SLE can have a variety of autoantibodies, including anticardiolipin antibodies, which can lead to a false positive syphilis test (due to cross-reactivity in the assays used for syphilis testing).

Question 8

All of the following are TRUE about the human immunodeficiency virus except

Accepted Answer

HIV is a retrovirus that contains RNA as its genetic material, not double-stranded DNA. Upon entering a host cell, its RNA is reverse-transcribed into DNA, which then integrates into the host's genome. Choices A, B, C, and E accurately describe characteristics and behaviors of HIV.

Question 9

The factor that inhibits complement- mediated lysis of red blood cells by dissociating C3 and C5 convertases is ________. Deficiency of this factor causes ________.

Accepted Answer

Decay accelerating factor (DAF) inhibits complement-mediated lysis of red blood cells by dissociating C3 and C5 convertases. Deficiency of DAF causes paroxysmal nocturnal hemoglobinuria (PNH).

Question 10

The autoantibody most characteristic of Graves' disease is ________.

Accepted Answer

The answer of The autoantibody most characteristic of Graves' disease...

Question 11

A clinical lab scientist observing the staining in an antinuclear antibody (ANA)test noted that the nuclei of interphase cells appeared to have dozens of dots scattered evenly over the entire nucleus. Chromosomes at metaphase did not show any staining. This pattern should be reported as homogeneous.

Accepted Answer

The description given matches the speckled pattern, not the homogeneous pattern. In a homogeneous pattern, the entire nucleus would appear uniformly stained, not dotted or speckled.

Question 12

AIDS is uniformly fatal because the human immune system responds so poorly to the HIV virus.

Accepted Answer

While AIDS is a serious condition, it is not uniformly fatal, especially with current treatments. Antiretroviral therapy can manage HIV infection, preventing its progression to AIDS and allowing individuals to live long, healthy lives.

Question 13

When drugs or viruses change self- antigens such that the immune system recognizes them as foreign, these altered self- antigens are called ________.

Accepted Answer

The answer of When drugs or viruses change self- antigens...

Question 14

An IgM antibody directed at the Fc portion of IgG is called ________.

Accepted Answer

The answer of An IgM antibody directed at the Fc...

Question 15

Deficiencies in complement components 5 through 9 are particularly associated with ________ infections.

Accepted Answer

The answer of Deficiencies in complement components 5 through 9...

Question 16

Individuals who have had their spleens removed may be immunodeficient.

Accepted Answer

The spleen plays a crucial role in filtering blood and mounting an immune response to certain bacteria, so its removal can lead to a compromised immune system, making individuals more susceptible to infections.

Question 17

Patients with active autoimmune diseases often have high blood C- reactive protein levels (CRP)and increased erythrocyte sedimentation rates (ESR).

Accepted Answer

Both C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are markers of inflammation in the body. Patients with active autoimmune diseases often experience inflammation, leading to elevated levels of CRP and increased ESR.

Question 18

A three- year- old child presents with repeated staphylococcal skin infections that take a very long time to resolve. The total white blood cell count is within normal limits and counts of all white blood cell types are within normal limits. All immunoglobulin and complement levels are within normal limits. A nitroblue tetrazolium (NBT)test is performed, and at the end of incubation, all neutrophils appear yellow. What is the best interpretation of these data?

Accepted Answer

The nitroblue tetrazolium (NBT) test is used to diagnose chronic granulomatous disease (CGD). In CGD, neutrophils cannot produce reactive oxygen species (ROS) due to a defect in the NADPH oxidase complex. The NBT test turns blue if neutrophils can produce ROS; yellow neutrophils indicate a failure to produce ROS, consistent with CGD.

Question 19

When kidney biopsies from patients with Goodpasture's syndrome are stained with fluorescent antihuman globulin, bright "beads" of fluorescence can be seen scattered randomly throughout the glomeruli.

Accepted Answer

In Goodpasture's syndrome, when kidney biopsies are stained with fluorescent antihuman globulin, the fluorescence typically outlines the glomerular basement membranes in a smooth, linear pattern rather than showing scattered "beads" of fluorescence. This linear pattern is indicative of the antibodies binding directly to the basement membrane.

Question 20

Rheumatoid arthritis is a progressive, asymmetrical, nondeforming arthritis that begins in the small joints (such as fingers)and progresses to the larger joints (such as hips).

Accepted Answer

Rheumatoid arthritis is a progressive, symmetrical, and potentially deforming arthritis that often begins in the small joints (such as those of the hands and feet) and can progress to larger joints.

Quiz 8: Autoimmune Diseases and Immunodeficiency Disorders