Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine Chapter 2: Problem 7
Matching: Match each of the following complementregulatory proteins with the pathological manifestation that would develop if this factor were defective: A. C1INH 1\. Atypical hemolytic uremic syndrome B. Factor \(\mathrm{H}\) \& factor \(\mathrm{I}\) 2\. Hereditary angioedema C. DAF 3\. Paroxysmal nocturnal hemoglobinuria
Short Answer
Expert verified
A-2, B-1, C-3
Step by step solution
01
- Match C1INH with Its Pathology
C1 inhibitor (C1INH) is a regulatory protein that prevents spontaneous activation of the complement system. When defective, it leads to excessive complement activation. This is most commonly associated with hereditary angioedema. Hence, C1INH matches with 2 (Hereditary angioedema).
02
- Match Factor H & Factor I with Their Pathology
Factors H and I regulate the complement pathway by inactivating C3b, preventing uncontrolled activation of the complement system. Defects in these factors can result in atypical hemolytic uremic syndrome, a condition where there is unregulated complement activity leading to damage of blood vessels and kidneys. Therefore, Factors H and I match with 1 (Atypical hemolytic uremic syndrome).
03
- Match DAF with Its Pathology
Decay-accelerating factor (DAF) protects cells from being lysed by complement by accelerating the decay of C3/C5 convertases. When DAF is defective, it results in increased red blood cell destruction, known as paroxysmal nocturnal hemoglobinuria. Thus, DAF matches with 3 (Paroxysmal nocturnal hemoglobinuria).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91影视!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
C1 inhibitor
C1 inhibitor (C1INH) is a crucial regulatory protein within the complement system. It essentially acts as a brake, stopping the pathway from being activated unnecessarily. This maintains balance and prevents damage from unintended complement activation. A defect in C1INH can lead to a condition called hereditary angioedema. This condition is characterized by episodic swelling in various parts of the body, including the extremities, face, gastrointestinal tract, and airways. In summary, C1INH is essential to keep the complement system in check and prevent disorders like hereditary angioedema.
Factor H
Factor H is a plasma protein that plays a pivotal role in regulating the alternative pathway of the complement system. It binds to C3b, a component of the pathway, and promotes its degradation. This limits the formation of the C3 convertase, thereby preventing excessive activation of the complement cascade. Defects in Factor H can contribute to atypical hemolytic uremic syndrome (aHUS), a severe condition characterized by the destruction of red blood cells, low platelet counts, and acute kidney injury. In essence, Factor H ensures the complement pathway does not become overactive and cause damage to the host's tissues.
Factor I
Factor I, like Factor H, is essential in regulating the complement system. It is a serine protease that cleaves and inactivates C3b and C4b, preventing the formation of C3/C5 convertases. Malfunctions in Factor I can also lead to atypical hemolytic uremic syndrome (aHUS). Patients with Factor I deficiency have an overactive complement system, resulting in the same symptoms seen with Factor H deficiencies like damaged blood vessels and compromised kidney function. Therefore, Factor I works alongside Factor H to maintain complement system homeostasis and prevent unwarranted cell destruction.
Decay-accelerating factor
Decay-accelerating factor (DAF) is a membrane protein that protects host cells from the complement system by accelerating the decay of C3/C5 convertases on the cell surface. Without DAF, cells become vulnerable to attack by the complement pathway, leading to conditions such as paroxysmal nocturnal hemoglobinuria (PNH). PNH is a rare genetic disorder where red blood cells are destroyed by the complement system, leading to hemoglobin release into the urine, fatigue, and other symptoms. Essentially, DAF is vital for protecting cells from being mistakenly lysed by the body's own immune system.
Hereditary angioedema
Hereditary angioedema (HAE) is a genetic disorder resulting from a deficiency or malfunction of the C1 inhibitor (C1INH). In HAE, the lack of proper C1INH leads to unchecked activation of the complement system, causing episodic swelling in various body parts. These swellings can be painful and sometimes life-threatening if they occur in the airways. HAE is typically inherited in an autosomal dominant fashion, meaning only one defective gene from a parent can cause the disorder. Treatment often involves the use of C1 inhibitors to manage and prevent acute episodes.
Atypical hemolytic uremic syndrome
Atypical hemolytic uremic syndrome (aHUS) is a rare, life-threatening disease marked by the destruction of red blood cells (hemolysis), low platelet counts (thrombocytopenia), and acute kidney damage (uremia). It arises from genetic or acquired defects in complement regulatory proteins like Factor H and Factor I. These defects allow the uncontrolled activation of the complement system, leading to blood vessel damage and kidney injury. Diagnosis typically involves blood tests, and treatment includes therapies aimed at inhibiting complement activity to prevent further damage.
Paroxysmal nocturnal hemoglobinuria
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder resulting from mutations that affect the synthesis of decay-accelerating factor (DAF), along with other proteins. Without these protective factors, red blood cells become susceptible to complement-mediated lysis, leading to symptoms such as dark urine (hemoglobinuria) especially in the morning, severe fatigue, and increased risk of blood clots. PNH is a chronic condition and can be serious if not managed properly. Treatment may include medications that inhibit the complement system and bone marrow transplants in severe cases.
