Furthermore, we have constructed quantitative assays for the determination of MASP -2 activity in serum or plasma, either when present as part of the MBL/MASP complex or as free MASP not associated with MBL. Pat. No. 7,083,786, which is a division of application Ser. No. 09/054,218, filed Apr. 2, 1998, now abandoned, which claims the benefit of Provisional Application No. 60/042,678, filed Apr. 3, 1997, all of which are hereby incorporated by reference. For a recent review on MBL, see ref. 6. Relatively high frequencies of MBL mutations associated with MBL-deficiency have been reported in all populations studied. This observation has led to the hypothesis that MBL may, in certain cases, render the individual more susceptible to certain intracellular infectious agents exploiting MBL to gain access to the target tissues21.
Reportedly, the level of MBL in plasma may be genetically determined9,10,11. MBL deficiency is associated with susceptibility to frequent infections with a variety of microorganisms in childhood12,13 and, possibly, in adults13,14.