Introduction: Burns, depending on the degree of severity, induce a significant pathophysiological response in the body. The complement system participates in the body's defenses as well as in immune responses after burn-induced trauma. Objectives: The main objective of the study was to examine how burn severity affects serum C3 and serum C4 complement values; whether burn severity correlates with serum C3 and C4 complement, and establish the predictive value of the serum C3 complement and serum C4 complement for assessing the severity of the burn.  Patients and methods: According to the degree of TBSA, patients were classified into three groups: group with %TBSA<15% (30 patients), group with %TBSA >15% -25% (30 patients), and group with %TBSA > 25% to 40% (30 patients). According to the depth of burns, patients were classified into two groups partial-thickness burns (39 patients) and full-thickness burns (51 patients). We followed laboratory parameters: value serum C3 complement and serum C4 complement on the first and seventh day after burn trauma. Results: Serum C3 complement was significantly lower in patients with %TBSA>25%-40% and in the group with %TBSA>15%-25% compared to patients with %TBSA<15% on the first and seventh day after burn trauma. Serum C3 complement was significantly lower in patients with %TBSA >15%-25% compared to patients with %TBSA<15% on day one and day seven after burn trauma. Serum complement C4 was not significantly different between burn groups on the first and seventh day. Full-thickness burns have significantly lower levels of serum complement C3, compared to partial-thickness burns, on the 1st and 7th day. Full-thickness burns result in a decrease in serum C4 complement compared to partial-thickness burns on the 7th day after burn trauma, but this decrease is not significant. On the 1st day after burn trauma, we found a negative correlation between %TBSA with serum C3 complement. Serum C4 complement was not correlated with %TBSA on the day 1st. Conclusions: %TBSA and depth of burn result in a significant decrease in serum C3 complement but not serum C4 complement. There is a negative correlation of %TBSA and C3 complement but not serum C4 complement on the 1st day after burn trauma. Serum C3 complement is a significant predictor of burn severity. The predictory significance of the C4 complement is not statistically significant.

Introduction: Burn, depending on the degree of severity and depth, induces significant pathophysiological  response of the body. Our study is the  prospective study  for  assessment of  T lymphocyte  immunological changes in patients with burns, with different degrees of  %TBSA  and depth of burns. Research objectives : Objectives of this study were to assess %CD3+Ly, % CD4+Ly,  %CD8+Ly, %CD3+HLA-DR+Ly, %CD4+Ly /CD8+Ly), of burned body with different   %TBSA degrees, different depth burns and to establish predictive value of of immune suppression  these  parameters. Patients and methods: According  to %TBSA, patients were classified into three groups:  mild  burns with TBSA% 25% to 40%  (30 patients).  According to the depth of burns, patients were classified into two groups, partial-thickness burns, (39 patients), and full-thickness burns (51 patients). We followed laboratory  parameters :  % CD3+Ly , % CD3+ CD4+Ly,  % CD3+CD8+Ly,  % CD3+HLA-DR+Ly, CD4 / CD8 (%) lymphocytes (on    day 7th and on   day 14th). Results: Percentage of CD3+ lymphocytes was significantly lower in severe  burns compared to the moderate  heavy  burns  andsignificantly lower compared to the mild  burns . Percentage of CD3+CD4+ lymphocytes was significantly lower in severe burns   compared to moderate  heavy burns   and  in relation to  mild burns  (results on day 14th );  also  are lower in moderate severe burn compared  to  mild burns. On day 14th, the% CD4 / CD8 ratio was not significantly lower in the severe burns versus the moderate  burns. On day 14th, the  % CD4 / CD8 ratio wassignificantly lower in severe burns compared to mild burns; significantly lower in moderateburns  compared  to  mild  burns. % CD3+HLA-DR + cells was significantly lower   in severe   burn and moderately  severe  burns  compared to the mild burns  on day 7th, and also on day 14th .  Full- thickness burns have significantly lower  %CD3+lymphocytes, %CD3+CD4+ lymphocytes,  %CD3+HLA-DR+ lymphocytes, ratio of % CD4/CD8 lymphocytes compared to partial-thickness burns  . Conclusions : Peripheral blood T lymphocytes are one of the key indicators of immunosuppression of patients with burns of different % TBSA and different degrees of burn depth.   Larger %TBSA and full- thickness burns injected stronger systemic immunosuppresion,   compared to smaller %TBSA and partial-thickness burns.