FM4 Immunology- Dr. Artaza Quiz 3 01/24/24

A 28-year-old HIV positive man is brought to the emergency department because of severe respiratory compromise. He is diagnosed with Pneumocystis pneumonia. Improved function of which of the following cells will aid in prevention of future infections?

• CD4+ T lymphocytes

• CD8+ T lymphocytes

• NK cells

• B lymphocytes

Answer explanation

Pneumocystis pneumonia or PCP is a fungal infection in one or both lungs. It can cause an opportunistic infection in people who have a weak immune system, such as people who have AIDS. AIDS stands for acquired immunodeficiency syndrome and is the final stage of infection with HIV. Not everyone with HIV develops AIDS if they are treated promptly. There are many medications that can control the HIV viral load and maintain the CD4 cell counts. These medications are called antiretroviral therapy (ART). Prompt treatment with ART prevents opportunistic infections such as PCP.

A newborn appears jaundiced at birth. Cord blood typing shows the neonate to be A positive. The mother is O positive. The most likely cause of this patient's disease is transplacental transfer of which of the following antibody types? 

• IgA

• IgE

• IgG

• IgM

Answer explanation

In ABO hemolytic disease of the newborn (also known as ABO HDN) maternal IgG antibodies with specificity for the ABO blood group system pass through the placenta to the fetal circulation where they can cause hemolysis of fetal red blood cells which can lead to fetal anemia and HDN.

IgA, IgE and IgM do not cross the placenta.

A 24-year-old female being treated for acute myeloid leukemia (AML) receives a bone marrow transplant from her sister. Day 10 post-transplant, she developed a diffuse skin rash, diarrhea, elevated liver enzymes and increased bilirubin. No evidence of infection or drug reaction is identified. Which of the following mechanisms is the most likely cause of the clinical symptoms?

• Host neutrophils binding to antineutrophilc antibody activating Donor cells

• Donor T-cells reacting against Host cells

• Host plasma cells secreting antibodies against Donor cells

• Donor macrophages secreting cytokines and affecting Host cells.

Answer explanation

Acute Graft-versus-host disease (GVHD) is a common, and sometimes serious side effect of an allogeneic transplant. GVHD happens when the cells from the donor (the graft) see the hosts cells (the recipient) as different and attack them.

Common acute symptoms include:

• Abdominal pain or cramps, nausea, vomiting, and diarrhea.

• Jaundice (yellow coloring of the skin or eyes) or other liver problems.

• Skin rash, itching, redness on areas of the skin.

• Increased risk for infections.

Chronic GVHD usually starts more than 3 months after a transplant, and can last a lifetime. Chronic symptoms may include: Dry eyes, burning sensation, or vision changes. Dry mouth, white patches inside the mouth, and sensitivity to spicy foods.