Deficiency in circulating natural killer (NK) cell subsets in common variable immunodeficiency and X-linked agammaglobulinaemia

Abstract

Absolute and relative NK cell numbers were determined in peripheral whole blood by flow cytometry in patients with common variable immunodeficiency (CVID) (n = 55) and X-linked agammaglobulinaemia (XLA) (n = 19) on regular immunoglobulin (IVIG) therapy. Absolute CD3-CD16+ NK cell numbers were significantly reduced in CVID patients (median 108/microl, range 23-815), compared with normal subjects (n = 60) (289/microl, range 56-640, P < 0.001). Total lymphocyte concentrations were significantly lower in CVID (median 1587/microl, range 523-7519) compared with normal subjects (median 2019/microl, range 1124-3149, P = 0.004), with the percentage of NK cells also being significantly decreased (median 7.5%, range 3.0-33. 0%, compared with 14.2%, range 2.6-30.8%, P < 0.001). In XLA, absolute NK cell numbers (median 140/microl, range 32-551, P < 0. 001) but not relative numbers were significantly reduced compared with normal controls. We excluded the possibility that IVIG interferes with in vitro binding of CD16 MoAbs. Further analysis of NK cell subsets showed a deficiency of both CD16+ and CD56+ cells in CVID, most marked in the CD3-CD8dim subpopulation, which may be due to increased homing of these cells to the gut. Serial studies on a small number of patients suggest that IVIG therapy has no short-term effect on NK cells, although we cannot exclude an effect with prolonged use. Although there are no obvious clinical effects of the NK depletion in CVID and XLA, this may be a factor in their predisposition to cancer.

Fig. 1

Effect of increasing concentrations of intravenous immunoglobulin (IVIG) on relative NK cell numbers from a single donor staining with anti-CD16 MoAbs (Ortho Diagnostics anti-CD16 clone 3G8 (•), Becton Dickinson anti-CD16 clone NKP15 (▪), Immunotech anti-CD16 clone 3G8 (▴)). For comparison, the percentage of lymphocytes staining with anti-CD56 (○) is shown. Increasing IgG concentrations do not reduce staining with the Ortho MoAb, but significantly interfere with the Becton Dickinson MoAb, and to a lesser extent with the Immunotech clone.

Fig. 2

Boxplots of absolute (a) and relative (b) numbers of NK cells in lymphocyte subset determinations in common variable immunodeficiency (CVID) (n = 55), X-linked agammaglobulinaemia (XLA) (n = 19) and healthy controls (n = 60). The hatched boxes show the median and the range between the 25th and the 75th percentile, tails show whiskers (defined as values within 1·5 of the interquartile range). ○, Outliers. *P < 0·05; **P < 0·01; ***P < 0·001 by Mann–Whitney U-test when compared with normals.

Fig. 3

(a) CD16⁺3⁻8⁻ and CD56⁺3⁻8⁻ NK cell subsets and co-expression of CD57 in normal subjects, common variable immunodeficiency (CVID) and X-linked agammaglobulinaemia (XLA) patients. (b) CD16⁺3⁻8^dim and CD56⁺3⁻8^dim NK cell subsets and co-expression of CD57 in normal subjects (n = 19), CVID (n = 11) and XLA patients (n = 6). Bars represent the median, tails represent the 25th to 75th percentiles. *P < 0·05; **P < 0·01; ***P < 0·001, by Mann–Whitney U-test when compared with normal subjects.

Fig. 4

NK cells before and after high dose intravenous immunoglobulin (hdIVIG) in patients with eczema (n = 3, ○, Δ, and □) and vasculitis (n = 1, ▴) within the total lymphocytes (a), the CD3⁻CD8^dim subpopulation (b) and the CD3⁻CD8⁻ subpopulation (c). The beginning of the lines represent the values before hdIVIG, the end of the lines the values immediately after hdIVIG. Double-positive cells for CD16 and CD56 become negative for CD16, especially in the CD3⁻CD8^dim subpopulation. Unless otherwise stated the Immunotech MoAb for CD16 is used. CD56 does not change. A discrepancy between Ortho Diagnostic and Immunotech antibodies is demonstrated.