Evaluation of Haemolytic Activity in Smokers by Using Non-Linear Regression

<b>Background and Objective:</b> Smokers are poorly protected against pathogens. Many studies have focused on the concentrations of complement components in comparison to smokers while ignoring the practical sequencing of complement components. There are numerous methods for estimating haemolytic activity (CH50%), all of which need a large number of samples and dilution, in addition to a typically expensive test kit. This novel study attempts to use statistical analysis and use the non-linear regression 'power equation' to extract the CH50% by using 5 serum dilutions only. <b>Materials and Methods:</b> The power equation can multiply the five practical dilutions into hundreds of mathematical loops within the sample range. The (CH50%) value is highly accurate for both the study and comparison sample and was evaluated in11 smokers. <b>Results:</b> The results were contrasted with a control composed of 11 individuals, matched by age and sex. The power equation showed a 6.48% significant reduction in (CH50%) in smokers compared with non-smokers, where a 17.54% reduction was observed. <b>Conclusion:</b> The current study suggests a decrease in the function of the classical complement pathway (CH50%) in smokers. On the other hand, the study provided a new statistical pattern, linking the practical values with default values within the range of dilution and formulating an equation that could be used to extract the value of CH50% with high accuracy.