Transplantologiya 2014

Correlation between

iNO and NOx	iNO and MetHb	NOx and MetHb
1 – A	r = 0.545, p = 0.129	r = 0.521, P = 0.150	r = 0.720, p = 0.029
2 - Bl	r = 0.828, p = 0.042	r = 0.105, p = 0.843	r = 0.174, p = 0.742
3 - B	R = 0.779, P = 0.013	-	-
4 - D	r = 0.853, p = 0.002	r = 0.880, p = 0.0008	r = 0.900, p = 0.0004
5 - K	r = 0.293, p = 0.573	-	-
6 - M	r = 0.393, p = 0.441	-	-
7 - P	r = -0.693, p = 0.039	r = 0.044, p = 0.911	r = -0.328, p = 0.389

The correlations observed for individual patients also confirm the fact that iNO is metabolized in the body to produce predominantly NOx.

Given the increasing number of LTs performed annually worldwide, enhanced studies are necessary to investigate the NO metabolism in the blood serum of the patients after successful LT and those who experienced an acute or chronic graft rejection. There are only a few reports on the studies to have investigated the levels of stable NO metabolites in patients after LT. So, De Andrade et al. [13] reported a significant increase of the total NOx concentrations in bronchoalveolar lavage (BAL) fluid and in the blood serum of the patients after LT compared to those of control subjects. These authors also demonstrated the correlation between serum NOx levels in the patients and the degree of airway inflammation, and fibrosis due to the transplant rejection [14]. Reid et al. [15] confirmed the findings of increased nitrite levels in patients after LT, however, stratifying the patients into the stable group and the group of those with bronchiolitis obliterans, they observed a significantly increased nitrite level in the BAL fluid in the latter group only. Increased circulating nitrite levels were reported in experimental studies in animals with acute cellular rejection of the graft [16, 17].

In our study, a statistically significant increase of the NOx level, approximately by 3-4 times, was observed in patients at 1-5 days after LT; and a significant positive correlation between the iNO administration and NOx levels was also found. The significant increase in serum NOx in patients at 1-5 days after LT, might be related to iNO metabolism and its transformation to NOx, and also to the activation of iNOS. Further studies of this issue are necessary.

CONCLUSION

The obtained results suggest that the iNO use in lung transplant recipients requires a close monitoring of the administered iNO concentration and the blood levels of MetHb and NOx.