CXCL10/IP-10: a missing link between inflammation and anti-angiogenesis in preeclampsia?

Evolution of non-cytotoxic uterine natural killer cells

The immune tolerance and de novo vascularization are two highly intriguing processes at the maternal-fetal interface that appear to be central to normal pregnancy outcome. Immune tolerance occurs despite the local presence of an active maternal immune system including macrophages, dendritic cells and specialized CD56(bright)CD16(-) uterine natural killer (uNK) cells (65-70%). Recent observations indicate that the phenotypic and functional repertoire of uNK cells is distinct from peripheral blood NK and endometrial NK cells, challenging the understanding of their temporal occurrence and function. Origin and specialized programming of uNK cells continue to be debated. uNK cells, replete with an armamentarium to kill the foreign, tolerate the conceptus and facilitate pregnancy. Why do these uNK cells remain non-cytotoxic? Are these NK cells 'multitasking' in nature harboring beneficial and detrimental roles in pregnancy? Are there distinct subpopulations of NK cells that may populate the decidua? We propose that the endometrium/decidua functions as an 'inducible tertiary lymphoid tissue' that supports the recruitment and expansion of CD56(bright)CD16(-) NK cells and induces transcriptional up-regulation of angiogenic machinery in response to exposure to local hormonal factors, cytokine milieu and perhaps hypoxia. The angiogenic features of uNK cells could further result in a 'multitasking' phenotype that still remains to be characterized. This article discusses the factors and pathways that bridge the angiogenic and non-cytotoxic response machineries at the maternal-fetal interface.

Maternal serum concentrations of the chemokine CXCL10/IP-10 are elevated in acute pyelonephritis during pregnancy

OBJECTIVE

Acute pyelonephritis is one of the most frequent medical complications of pregnancy, as well as a common cause of antepartum hospitalization. Interferon (IFN)-gamma inducible protein, CXCL10/IP-10, is a member of the CXC chemokine family with pro-inflammatory and anti-angiogenic properties. The purpose of this study was to determine whether maternal serum concentrations of CXCL10/IP-10 change in patients with acute pyelonephritis during pregnancy.

STUDY DESIGN

This cross-sectional study was conducted to determine the difference in maternal serum concentrations of CXCL10/IP-10 in pregnant women with acute pyelonephritis (N = 41) and normal pregnant women (N = 89). Pyelonephritis was defined in the presence of a positive urine culture, fever, and maternal clinical signs; blood cultures were performed in 36 cases. Maternal serum concentrations of CXCL10/IP-10 were measured by a sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

(1) The median serum concentration of CXCL10/IP-10 in pregnant patients with pyelonephritis was significantly higher than in normal pregnant women (median 318.5 pg/mL, range 78.8-2459.2 vs. median 116.1 pg/mL, range 40.7-1314.3, respectively; p < 0.001); (2) maternal median serum concentrations of CXCL10/IP-10 did not differ significantly among patients with acute pyelonephritis with and without bacteremia (positive blood cultures: median 362.6 pg/mL, range 100.2-2459.2 vs. negative blood cultures: median 298.9 pg/mL, range 108.5-1148.7, respectively; p = 0.3).

CONCLUSIONS

Pyelonephritis in pregnant women is associated with an increased maternal serum concentration of the chemokine CXCL10/IP-10.