Effect of storage time and temperature on the results of analysis of synovial and mesothelial fluids.

The research article explores how the storage time and temperature of equine body fluid samples affect analytical results and diagnostic interpretation, focusing on proteins and cell parameters. The results showed that delays in sample analysis, particularly at higher storage temperatures, led to changes in neutrophil and cell count, potentially impacting clinical judgments.

Objective and Methods

• The research aimed to understand how the length of storage and temperature can alter the results derived from equine synovial and mesothelial cavity fluids. The objective was chiefly to determine if any such changes could distort clinicopathological explanations.
• The samples for the study were obtained during diagnostic investigations on horses. Each sample was stored and analyzed at 4 or 22 degrees Celsius at various time intervals: immediately and after 24, 48, and 72 hours.
• The analytical parameters under scrutiny in this study were total protein concentration (TP), total nucleated cell count (TNCC) and neutrophil morphology. A linear mixed model was employed to analyze the effects of fluid type and storage conditions on these parameters.

Results

• Among the 32 samples collected from 23 horses, storage time and temperature had no discernible effect on the TP.
• Cell count decreased significantly over time and was influenced by the type of fluid. It reduced significantly at T for storage at 4°C and at T, T, and T for 22°C.
• Neutrophil morphology was also affected, showing a significant increase at T, T, and T compared to T, irrespective of whether they were stored at 4 or 22°C.
• The storage conditions resulted in changes in the diagnostic interpretation for nine samples.
• While the specificity and positive predictive value at each analysis point retained a 100% score, the sensitivity and negative predictive value decreased with higher storage durations and temperature.

Conclusions

• The study concluded that the TNCC and neutrophil morphology of body fluid samples undergo modifications when the analysis is postponed, especially when stored at higher temperatures. These changes can influence diagnostic interpretations and clinical decision-making.
• It is suggested that body fluid samples should be analyzed as immediately as possible post-collection to minimize pre-analytical errors brought about by their storage.