MAC is Membrane Attack Complex which is an integral part of Complement system of the blood. I want to know which diseases are caused due to its deficiency. I am planning a trial for this topic, please revert back.
Recurrent Neisseria infections, particularly meningococcal (esp serogroups W-135 and Y). Confounding this is that other deficiencies in the complement cascade (such as Factor B and D) can manifest with recurrent meningococcal infections. Generally, increased risk of bacteremia is also seen with MAC deficiency, but is also observed with deficiencies in early complement components. I highly recommend reading this review for more info:
Pettigrew, H. D., Teuber, S. S. and Gershwin, M. E. (2009), Clinical Significance of Complement Deficiencies. Annals of the New York Academy of Sciences, 1173: 108–123. doi: 10.1111/j.1749-6632.2009.04633.x
As you know recently a precious help for two very critical syndromes, paroxysmal nocturnal hemoglobinuria and atypical hemolitic uremic syndrome, arrived from a novel MAC inhibitor, eculizumab. This drug is a C5 humanized antibody; when a patient is treated with this drug the only known risk of MAC inhibition is the increased risk of neisseria and all the capsulated bacteria infections.