Comparisons of CVID and IgGSD: Referring Physicians, Autoimmune Conditions, Pneumovax Reactivity, Immunoglobulin Levels, Blood Lymphocyte Subsets, and HLA-A and -B Typing in 432 Adult Index Patients

Table 3

Serum immunoglobulins in 432 adult CVID/IgGSD index patients¹.

Ig isotype	CVID ()	IgGSD ()	Value of
Median IgG, g/L	5.51 (3.75, 6.92)	7.58 (3.43, 21.56)	<0.0001
Subnormal IgG, % ()	100.0 (34)	33.9 (135)	<0.0001
Elevated IgG, % ()	0	1.3 (5)	0.5109
Median IgG1, g/L	3.24 (2.42, 4.37)	4.10 (0.95, 14.60)	<0.0001
Subnormal IgG1, % ()	97.1 (38)	56.3 (228)	<0.0001
Elevated IgG1, % ()	0	0.3 (1)	0.7698
Median IgG2, g/L	1.34 (0.17, 3.50)	2.51 (0.31, 16.50)	<0.0001
Subnormal IgG2, % ()	35.3 (12)	8.8 (35)	<0.0001
Elevated IgG2, % ()	0	0.3 (1)	0.7698
Median IgG3, g/L	0.39 (0.07, 1.06)	0.33 (0.06, 1.76)	0.5821
Subnormal IgG3, % ()	58.8 (20)	70.9 (282)	0.3336
Elevated IgG3, % ()	0	1.5 (6)	0.4709
Median IgG4, g/L	0.08 (0, 0.29)	0.13 (0, 2.37)	0.0008
Subnormal IgG4, % ()	5.9 (2)	3.3 (13)	0.4239
Elevated IgG4, % ()	0	0	—
Median IgA, g/L	0.56 (0.04, 0.69)	1.55 (0.04, 5.55)	<0.0001
Subnormal IgA, % ()	100.0 (34)	5.3 (21)	<0.0001
Elevated IgA, % ()	0	2.5 (10)	0.3497
Median IgM, g/L	0.55 (0.10, 1.88)	1.00 (0.04, 5.16)	<0.0001
Subnormal IgM, % ()	26.5 (9)	13.6 (54)	0.0407
Elevated IgM, % ()	0	7.3 (29)	0.1032

CVID, common variable immunodeficiency; IgGSD, IgG subclass deficiency; Ig, immunoglobulin; SD, standard deviation. Reference ranges (mean ± 2 SD) are IgG 7.00–16.00 g/L; IgG1 4.22–12.92 g/L; IgG2 1.17–7.47 g/L; IgG3 0.41–1.29 g/L; IgG4 0.01–2.91 g/L; IgA 0.70–4.00 g/L; and IgM 0.40–2.30 g/L. Subnormal Ig levels were defined as those below the corresponding lower reference limit. Elevated serum Ig levels were defined as those greater than the upper reference limit. Serum Ig levels are expressed as median (range). Comparisons were made with Mann-Whitney test, Pearson’s test, or Fisher’s exact test, as appropriate.