## 3 Results  
We demonstrated no correlations between serum HSP90 and CD3+ \(\gamma\delta\) T cells before and after induction chemotherapy (before R = 0.01, after treatment R = \(-\)0.41), CD4+ \(\gamma\delta\) T cells (before R = 0.21, after treatment R = \(-\)0.07) and CD8+ \(\gamma\delta\) (before R = 0.31, after treatment R = 0.09).  
The same investigations also showed no statistically relevant differences among healthy controls (serum HSP90 and CD3+ \(\gamma\delta\) T cells R = 0.45; CD4+ \(\gamma\delta\) T cells R = 0.2; CD8+ \(\gamma\delta\) T cells R = 0.12).  
Analysis showed a strong association between serum HSP90 and CD3+ HLA/DR+ \(\gamma\delta\) T cells in ALL patients before treatment (R = 0.53, \(p<0.05\)) vs after induction protocol (R = 0.13); after removal of the outlier (23.85 ng/mL) the correlation between serum HSP90 and CD3+ HLA/DR+ \(\gamma\delta\) T cells remained still strong (R = 0.53, \(p<0.05\)) (Figure 1). The same patient presented extremely high level of serum HSP90 after treatment (52.51 ng/mL) as well. The difference among the healthy controls was R = \(-\)0.2 (Table 2).  
In our previous report, we demonstrated that patients before and on the 33 rd day of therapy showed decreased serum HSP90 levels compared to healthy controls with a higher difference on the day of diagnosis than after 33 rd day [11].  
Interestingly, CD3+ HLA/DR+ \(\gamma\delta\) T cells were also decreased before chemotherapy relative to the moment after induction protocol.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Serum HSP90**} \\ \hline \multicolumn{3}{c}{**Before Chemotherapy**} & **After Chemotherapy** & **Controls** \\ \hline Diagnosis & & & \\ \hline CD3 + \(\gamma\delta\) T cells & 0.01 & 0 * & 0.45 \\ \hline CD3 + HLA/DR + \(\gamma\delta\) T cells & 0.53 & 0.06 * & \(-\)0.20 \\ \hline CD4 + \(\gamma\delta\) T cells & 0.21 & \(-\)0.08 * & 0.20 \\ \hline CD8 + \(\gamma\delta\) T cells & 0.31 & 0.09 * & 0.12 \\ \hline After chemotherapy & & & \\ \hline CD3 + \(\gamma\delta\) T cells & \(-\)0.41 * & 0.02 & \\ \hline CD3 + HLA/DR + \(\gamma\delta\) T cells & 0.13 * & \(-\)0.27 & \\ \hline CD4 + \(\gamma\delta\) T cells & \(-\)0.07 * & 0.13 & \\ \hline CD8 + \(\gamma\delta\) T cells & 0.09 * & 0 & \\ \hline \hline \end{tabular}  
* results not described in the main text.  
\end{table}
Table 2: The results of the correlation coefficient between serum HSP90 and \(\gamma\delta\) T cells in the research group and controls.  
The median CD3+ HLA/DR+ \(\gamma\)\(\delta\) T cells on the day of the diagnosis was 2.36% (range 0.91-13.00%), and 4.96% (range 0.88-55.17%) on the 33 rd day of therapy. Median CD3+ HLA/DR+ \(\gamma\)\(\delta\) T cells among the control group was 5.24% (range 1.6%-13.88%). We found statistical differences between CD3+ HLA/DR+ \(\gamma\)\(\delta\) T cells in ALL patients in two time points (\(p\) = 0.029, Wilcoxon signed-rank test). Children at disease presentation showed a decreased level of CD3+ HLA/DR+ \(\gamma\)\(\delta\) T cells compared to the healthy controls (\(p\) = 0.026, U Mann-Whitney test). However, there was no statistical significance between the level of the lymphocytes among patients on the 33 rd day of therapy in comparison to the healthy children (\(p\) = 0.627, U Mann-Whitney test) (Figure 2).  
We found no statistical differences before and after chemotherapy (Wilcoxon signed-rank test) in the levels of CD3 + \(\gamma\)\(\delta\) T cells (\(p\) = 0.87), CD4 + \(\gamma\)\(\delta\) T cells (\(p\) = 0.57), and CD8 + \(\gamma\)\(\delta\) T cells (\(p\) = 0.39) (Table 3).  
Figure 1: Correlation of activated serum HSP90 and CD3 + \(\gamma\)\(\delta\) T cells among children with ALL at diagnosis.