Total homocysteine plasmatic levels as a marker of clinical severity in septic patients

Introduction

Homocysteine is a sulfur-containing amino acid formed during methionine metabolism that has been appointed as a marker of cardiovascular disease. The mechanisms involved are unclear, but include an increase in oxidative stress, excessive thrombogenesis, mitotic alterations in smooth muscular cells and endothelial dysfunction. Some of these mechanisms are present in septic patients, suggesting that total homocysteine (tHcy) levels might be implicated in the pathogenesis of organ dysfunction. The objective of this study is to correlate tHcy levels and the severity of septic process, evaluated by SOFA score.

Methods

In this prospective clinical trial, patients admitted in a tertiary universitary intensive care unit with severe sepsis were included, before 48 hours of organ dysfunction diagnosis. Patients with acute renal failure were excluded. Blood samples were collected after 8 hours of starvation, and SOFA parameters, on days 1, 3, 7 and 14 after inclusion. Statistical analysis was done using the Kappa test.

Results

We studied tHcy in 30 samples of 10 patients (three female and seven male) with a mean age of 46.9 ± 24.5 years and a mean APACHE score of 19.5 ± 8.4 (minimum 10, maximum 35). The mean tHcy values for each day studied were 6.299 ± 3.183 μmol/l (n = 10), 5.425 ± 1.343 μmol/l (n = 9), 7.216 ± 3.091 μmol/l (n = 7), and 7.024 ± 4.265 μmol/l (n = 4) for days 1, 3, 7 and 14, respectively. The mean SOFA scores were 2.00 ± 0.98 (n = 10), 1.58 ± 0.72 (n = 9), 1.32 ± 0.62 (n = 7), and 0.68 ± 0.55 (n = 4) for days 1, 3, 7 and 14, respectively. After analysis with the Kappa test, the concordance coefficient (K_w) was 0.02 with a z_cal of 0.20 (not significant), resulting in a poor level of agreement between these two parameters.

Conclusion

Our results suggest that homocysteine levels could not be related to organ dysfunction in this septic patient population. These results must be confirmed in a larger population of septic patients.