Elevated Levels of Serum Sulfite in Patients with Chronic Renal Failure

Abstract

Abstract. Sulfite, a well known air pollutant, is toxic for humans, especially those with sulfite hypersensitivity. Sulfite is also generated endogenously, during normal metabolism of sulfur-containing amino acids. Mammalian tissues contain the enzyme sulfite oxidase, which detoxifies both endogenous and exogenous sulfite by oxidation to sulfate. Deficiency of sulfite oxidase in humans is fatal, demonstrating its physiologic importance. Nevertheless, information about serum and tissue levels of sulfite in normal and pathologic conditions is limited. Using a sensitive HPLC assay, it is shown here that sera from patients with chronic renal failure (CRF) contain significantly higher amounts of sulfite than those from healthy subjects. Mean ± SD of serum sulfite in healthy subjects (n = 20) was 1.55 ± 0.54 μM, whereas those in patients under maintenance hemodialysis (HD patients; n = 44) and CRF patients before introducing dialysis therapy (pre-HD patients; n = 33) were 3.23 ± 1.02 μM (P < 0.01) and 3.80 ± 3.32 μM (P < 0.01), respectively. Among pre-HD patients, serum sulfite was positively correlated with serum creatinine (r = 0.714, P < 0.0001), and negatively with serum albumin (r = -0.407, P = 0.0188), hematocrit (r = -0.524, P = 0.0017), and total cholesterol (r = -0.375, P = 0.0318). There was no significant association between sulfite and patient age, gender, or leukocyte counts. Multiple regression analysis revealed serum creatinine as the sole independent predictor of serum sulfite levels. Each HD treatment was associated with approximately 27% reduction in serum sulfite levels, suggesting the presence of a dialyzable form in serum. Thus, these results indicate that reduced glomerular filtration is a factor that determines serum sulfite levels. Chronic elevation in serum sulfite levels might contribute to tissue or organ dysfunction in patients with CRF.

Strong Anion Determination in Biological Fluids by Capillary Electrophoresis for Clinical Diagnostics

“…In general, biological fluids are analyzed directly after a simple dilution or filtration step with minimal sample workup. Due to its tendency to spontaneously oxidize to sulfate, sulfite analysis is not performed routinely in clinical laboratories despite its relevance to the diagnosis of sulfite oxidase deficiency, chronic renal failure, acute pneumonia, sulfite-related allergies, and other disorders associated with sulfur metabolism and/or molybdenum deficiency. Qualitative urine test strips are used for detection of sulfite when performing confirmatory testing of sulfite oxidase deficiency; however, they suffer from false-positives due to matrix interferences and false-negatives if samples are not properly stored .…”

Ultrafast Detection of Sulfur Dioxide Derivatives by a Distinctive “Dual-Positive-Ion” Platform that Features a Doubly Activated but Irreversible Michael Addition Site

“…Accumulating studies have verified that the concentrations of SO 2 in pathophysiologic conditions are higher than those in normal physiological environments. For example, serum sulfite concentrations in pneumonia patients and healthy subjects were determined to be 3.75 ± 0.88 and 1.23 ± 0.48 μM, and the concentrations of serum sulfite in chronic renal failure patients and healthy subjects were 3.80 ± 3.32 and 1.55 ± 0.54 μM, respectively. Especially, the fluorescence intensity of CMQ showed good linearity against the concentrations of HSO 3 – in the range of 0–6 μM.…”

Dicyanoisophorone-Based Near-Infrared-Emission Fluorescent Probe for Detecting NAD(P)H in Living Cells and in Vivo

“…The fluorescence intensities at 660 nm only increased dramatically when NAD­(P)H was added, but all the other analytes occupied quite low responses (Figure ). Notably, sulfite has a considerably higher fluorescence-intensity change than other materials, but it is still negligible compared with that of NAD­(P)H because of its low in vivo concentration (0.2 and 4.87 μM). − Meanwhile, after DCI-MQ reacted with NADH, the fluorescence intensities yielded negligible changes after the addition of various reactive oxygen species (ROSs), including O 2 ·– , H 2 O 2 , NaClO, t -BuOOH, and NO (Figure S2), which indicates that the reaction product also has high stability. These data further validate that DCI-MQ possesses high selectivity for NAD­(P)H under physiological conditions and therefore could be used potentially for the specific detection of NAD­(P)H in biological samples.…”