Your patient is a 23-year-old man who admits that he has chlamydia. He complains of lower abdominal pain and nausea, and says he has swelling in one testicle. He also says the pain has been increasing for the last couple of days. Which of the following should you suspect?

All of the following are true about the classical pathway except

a. Begins with formation of C1 from C1q, C1r, and C1s molecules b. Consists of C5b and C6-C9 c. Is regulated by two mechanisms in the fluid phase d. Is regulated on cell surfaces with complement control proteins

Which of the following tests would help differentiate primary polycythemia from secondary polycythemia?

a. EPO b. Vitamin B12 c. Iron d. LAP score