Interference with serum indices measurement, but not chemical analysis, on the Roche Modular by Patent Blue V

Abstract

The effects observed on the Roche Modular serum index measurements with Patent Blue raises the novel concept of interference in methods routinely used to detect interference. Despite Patent Blue having no direct effect on chemical analysis, failure to reliably detect potential interference, particularly haemolysis, may lead to misleading results being issued.

Measurement of icteric index as approach to detect abnormal total bilirubin values

“…In some cases, the II photometric measurement may be influenced by interferences due to the presence of dyes. For instance, an interference on serum indices by Patent Blue V, an inert dye used during cancer surgery, was reported on Roche Modular system 2. Particularly, a significant negative interference was observed on the II, while no interference was found on TB measurement on serum samples that on visual inspection turned out to be bright green 2.…”

“…For instance, an interference on serum indices by Patent Blue V, an inert dye used during cancer surgery, was reported on Roche Modular system 2. Particularly, a significant negative interference was observed on the II, while no interference was found on TB measurement on serum samples that on visual inspection turned out to be bright green 2. More importantly, it is worth to keep in mind that, in general, haemolysis, icteric and lipemic indices measured automatically on serum and plasma are only semi-quantitative tests aimed to assess sample quality as indicators of interference.…”

Effect of Patent Blue V® dye on sample interference indices on the Abbott Architect

“…We read with interest an article on the interference caused by Patent Blue V w dye in the serum sample interference indices on the Roche modular (F Hoffmann-La Roche, Basel, Switzerland), 1 after noticing the same dye caused a similar effect on these indices on the Abbott Architect (Abbott Laboratories, Chicago, IL, USA). Patent Blue V w is a dye that is used in certain surgical procedures, in particular to guide sentinel lymph node biopsy.…”

“…These findings are consistent with those of the study on the effect of Patent Blue V w on the Roche modular sample interference indices. 1 Scanning spectrophotometry (between 326 and 700 nm) using a Unicam UV/visible spectrophotometer (Unicam Analytical Systems, Madison, WI, USA) revealed a peak at 630 nm in the green samples (Figure 1), which was not present in the serum sample with a normal appearance. The presence and size of the peak at 630 nm correlated with the change in the sample interference indices.…”

“…1 However, the interference caused by Patent Blue V w has the potential to mask the presence of haemolysis or icterus, and exaggerate the presence of lipaemia. Therefore, in theory, a spurious result could be issued in such samples, e.g.…”