Abstract:
There are over fifty methods which have been described for the
assessment of immune complexes in sera or plasma. The measurement of
circulating immune complexes in sera of patients with different diseases has
been frequently used for the assessment of disease activity for the purposes
of disease management/therapy and control. Complement 1q (C1q) binding
assay has been the most widely used. In the present study circulating
immune complexes (CIC), were measured for the purposes of assessing the
relationship with the severity of Plasmodium falciparum severe malarial
anaemia. Three methods were used, with two being C1q-based assays and a
novel CR1 binding assay. The ability of the methods to discriminate between
the severe malarial anaemia cases and their controls was assessed with
reference to a common heat aggregated human IgG standard. The three
methods used showed a similar trend in detection of levels of CIC in sera and
all methods showed elevated levels of CIC in sera of severe malarial anaemia
cases compared to their controls. When the cases were compared to their
symptomatic controls, the commercial Quidel C1q kit showed a significance
difference between SA and UM of p = 0.04 while C1q in-house assay
showed a highly significant difference for the two groups (p = 0.01). CR1
binding assay also showed a significance difference between SA and UM (p
= 0.04). When cases were compared to their symptomatic controls, Quidel
C1q kit had p = 0.001, C1Q in-house assay had p = 0.006 while CR1 binding
assay had p = 0.01.Their level of detection differed and this can be attributed to different tracing
principles and the nature or properties of the immune complexes detected.
From the results it shows that for the screening of CIC in sera, the use of two
or more methods will enable detection of ICs of various sizes and
complexities, and the nature of IC should be considered so as to select the
most appropriate method that will enable a valid assessment to be carried out
