Factors associated with IgG levels in adults with IgG subclass deficiency

BMC Immunology

Table 3 Characteristics of 115 adults with IgGSD and subnormal IgG3 only^a

Women, % (n)	87.8 (105)
Mean age at diagnosis, y ± 1 SD	47 ± 13
Autoimmune condition(s), % (n)^b	31.3 (36)
Atopy, % (n)^c	27.8 (32)
Autoimmune condition(s) and atopy, % (n)	6.1 (7)
Mean IgG, g/L ± 1 SD	10.00 ± 1.87
Median IgG1, g/L (range)	5.77 (4.23, 10.70)
Mean IgG2, g/L ± 1 SD	3.23 ± 1.20
Mean IgG3, g/L ± 1 SD	0.28 ± 0.08
Median IgG4, g/L (range)	0.23 (0.01, 2.37)
Median IgA, g/L (range)	1.85 (0.71, 5.55)
Median IgM, g/L (range)	1.19 (0.43, 5.16)

^aIgGSD, IgG subclass deficiency; SD, standard deviation. Subnormal IgG3 is defined as a value < 2 SD below the mean. No patient had subnormal serum levels of IgG1, IgG2, IgG4, IgA, or IgM. Six of 101 women (5.9%) had elevated IgA. Sixteen of 101 women (15.8%) had elevated IgM. Neither elevated IgA nor elevated IgM was observed in the ten men represented herein
^bAutoimmune condition(s) were diagnosed in 36 patients: anti-nuclear antibody > 1:80 without other explanation (5); anti-phospholipid antibody syndrome (1); autoimmune thyroiditis (2); Behçet syndrome (1); Crohn’s disease (2); Graves disease (1); mixed connective tissue disorder (1); psoriasis (3); psoriatic arthritis (2); rheumatoid arthritis (8); sarcoidosis (1); Sjögren syndrome (6); systemic lupus erythematosus (3); ulcerative colitis (1); and vitiligo (1)
^cAtopy was diagnosed in 32 patients (22 allergic asthma; 10 allergic rhinitis; 3 allergic eczema). Three of the 32 patients (9.4%) had two atopy conditions

ISSN: 1471-2172