The author experienced the remarkable effect of the IgG replacement therapy in a patient with intractable pyogenic infections who had a selective IgG4 deficiency. For extending this experiences to patients with chronic or recurrent pyogenic
infections,
the author measured the IgG subclasses serum levels of thirty children who had recurrent pyogenic in fection(Tabel 1). All the other immunological studies of these patients were normal
The modified radial immunodiffusion (RID) technique was used for the screening test, Briefly, polyclonal subclass monospecific antiserum mixed with 2% agarose in 0.05M Tris buffer (aniserum concentration : 1mg/ml), and 2ml of this mixture poured
onto
the coated 2ml of this mixture poured onto the coated glass (26×57mm : coated with 0.02% noble agar). The subclass antisera (which were of sheep orgin) were supplied by The Binding site (Birmingham, England). The prepared gel was punched out to
make 18
wlls (diamenter 1.75mm, volume approximately 3μl). These wells were filled with appropriately diluted samples an standard serum, and incubated two days at room temperature. Dilution factor for human serum samples : IgG1 1 : 10, IgG2 1 : 10, IgG3
&
IgG4
neat. The diameter of the rings were measured, and actual value were calculated with standard curve. The data were compared with arbitrary normal ranges in childhood(fig. 2) which the author depicted form the data reported worldwide.
Four of thirty children have IgG3 serum levels below the low limits,and the other four children have IgG4 serum levels below the low limits. There findings suggest that IgG-subclass deficiency may play an etiologic role in chronic or recurrent
pyogenic
infections.(fig.1).
Therefore, the author concludes that it is important to screen patients with chromic or recurrent infection for IgG-subclass deficiencies in view of the reported beneficial response to gamma-globulin therapy.
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