Deficiencies in C4A and C4B Isotypes of Human Complement Revealed by Isoelectrofocusing and Chemical Reactivity of Activated Forms

M. V. Lakhtin1, L. V. Kozlov1 #, V. M. Lakhtin1 and V. L. D’yakov1


1Gabrichevskii Research Institute of Epidemiology and Microbiology, ul. Admirala Makarova 10, Moscow, 125212, Russia

Received: May 31, 2006;  in final form: February 15, 2007

Abstract.  An approach is proposed to detect deficiencies in isotypes A and B of the C4 component of human complement, based on the calculation of the ratio of their IEA activities and the ratio of their quantities determined by isoelectrofocusing of their desialated forms with chemiluminescent detection in an immunoblot. The ratios of the quantities and activities of C4A/C4B practically coincided when determined in blood serum of 20 patients, many of which had inherited deficiencies in the C4 component isotypes.

Key words:  complement system, isotypes C4A and C4B, functional activity assay, IEA, isoelectrofocusing

Russian Journal of Bioorganic Chemistry 2007, 33 (4): 431-435