How are Type IV hypersensitivity reactions different from all other types (I, II, or III) of hypersentivity reactions?
The usual types of reactions are mediated by antibodies.
B-lymphocytes produce the offending substances.
They typically occur with the first exposure to an antigen.
Delayed reactions are characterized by cytokine release.
The Correct Answer is A
A) The usual types of reactions are mediated by antibodies:
Correct. Types I, II, and III hypersensitivity reactions are mediated by antibodies (IgE, IgG, or IgM) that bind to antigens and trigger immune responses. In contrast, Type IV hypersensitivity reactions are T-cell mediated and do not involve antibodies.
B) B-lymphocytes produce the offending substances:
This statement is incorrect. B-lymphocytes are involved in antibody-mediated immune responses (types I, II, and III hypersensitivity reactions), not Type IV hypersensitivity reactions, which are primarily mediated by T-lymphocytes.
C) They typically occur with the first exposure to an antigen:
This statement is incorrect. Type IV hypersensitivity reactions usually require sensitization upon initial exposure to an antigen, and subsequent exposures elicit the delayed hypersensitivity response. This is similar to types I, II, and III hypersensitivity reactions, which also involve sensitization upon initial exposure.
D) Delayed reactions are characterized by cytokine release:
This statement is partially correct. Type IV hypersensitivity reactions are characterized by a delayed onset (typically 24 to 72 hours after exposure) and involve the release of cytokines from activated T-lymphocytes, leading to inflammation and tissue damage. However, other types of hypersensitivity reactions may also involve cytokine release, so this feature alone does not differentiate Type IV from other types of reactions.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
The client's symptoms, along with the elevated serum amylase and lipase levels, suggest the development of acute pancreatitis as a postoperative complication. Here's a detailed explanation for why option A is the correct choice:
A) Acute pancreatitis:
Correct. Acute pancreatitis is characterized by inflammation of the pancreas, which can be triggered by various factors, including gallstones, alcohol consumption, and certain medications. In this case, the client's recent cholecystectomy for cholelithiasis (gallstones) may have led to the development of acute pancreatitis. The persistent upper abdominal pain radiating to the back, along with vomiting and fever, are classic symptoms of acute pancreatitis. Elevated serum amylase and lipase levels are common laboratory findings in acute pancreatitis due to pancreatic cell injury and leakage of these enzymes into the bloodstream.
B) Surgical site infection:
While surgical site infections are potential complications of cholecystectomy, the client's symptoms, including upper abdominal pain, vomiting, and fever, are more indicative of a systemic inflammatory process rather than localized infection at the surgical site.
C) Hepatorenal failure:
Hepatorenal failure, also known as hepatorenal syndrome, refers to kidney dysfunction that occurs as a complication of advanced liver disease. The client's symptoms and laboratory findings are not consistent with hepatorenal failure, as there are no signs of significant liver dysfunction or advanced liver disease.
D) Biliary duct obstruction:
While biliary duct obstruction can lead to symptoms similar to those of acute pancreatitis, such as upper abdominal pain and vomiting, the presence of elevated serum amylase and lipase levels strongly suggests pancreatic involvement rather than isolated biliary duct obstruction.
Correct Answer is C
Explanation
Chronic osteoarthritis (OA) is a degenerative joint disease characterized by the breakdown of joint cartilage and underlying bone changes. The pathophysiological process of OA involves various factors contributing to joint pain and inflammation. Here's why option C is the correct choice:
A) Inflammation results from deposition of crystals in the synovial space of joints producing irritation:
This statement is more characteristic of crystal-induced arthritis, such as gout or pseudogout, where crystals (e.g., urate or calcium pyrophosphate crystals) deposit in the joints and cause acute inflammation and irritation. While inflammation may occur in OA, it is primarily a result of mechanical stress and cartilage degradation rather than crystal deposition.
B) Inflammation is caused by immune complex and autoantibody deposition in connective tissue:
This statement is more characteristic of autoimmune diseases such as rheumatoid arthritis (RA), where immune complex deposition and autoantibody production lead to chronic inflammation and joint damage. In OA, inflammation is not primarily mediated by immune complex deposition or autoantibodies.
C) Joint inflammation occurs when chondrocyte injury destroys joint cartilage, producing osteophytes:
Correct. In osteoarthritis, joint inflammation occurs as a result of chondrocyte injury and cartilage breakdown. Over time, the degenerative changes in the joint lead to the formation of osteophytes (bone spurs) at the joint margins. These changes can irritate surrounding tissues, including the synovium, ligaments, and tendons, contributing to joint pain and inflammation.
D) Joint destruction happens due to an autoimmune inflammation involving IgG response to an antigen:
This statement is more characteristic of autoimmune arthritis, such as rheumatoid arthritis (RA), where autoantibodies (e.g., rheumatoid factor, anti-citrullinated protein antibodies) target joint tissues, leading to chronic inflammation and joint destruction. In OA, joint destruction primarily results from mechanical stress and wear-and-tear on the joint structures rather than autoimmune mechanisms.
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