Introduction

The allogeneic Hematopoietic Stem Cells Transplantation (alloHSCT) is associated with the risk of Graft versus Host Disease (GvHD) and infections. The pathogenesis of acute GvHD is related to T-lymphocytes, which identify alloantigens on host's Antigen Presenting Cells, induce production of IFN-γ and IL-2, recruit the immunological effectory cells and destroy tissues and organs.

Aim

The aim of the study was to analyse the relationship between IL-2 and IFN-γ serum concentrations and acute GvHD and infections.

Material and methods

The study involved 62 patients, 30 (48%) male and 32 (52%) female, aged at median 49.5 (19–68) years, after alloHSCT from sibling (n=12) or from unrelated donor (n=50) performed for acute myeloid leukemia (AML) with myeloablative conditioning (n=26, 42%) and with non-myeloablative conditioning (n=36, 58%) in Katowice in years 2012–2014. All patients received standard immunosuppressive therapy with cyclosporin-A and methotrexate plus pre-transplant anti-thymocyte globulin in unrelated setting. Blood samples were collected pre-transplant before start and after (on day -1) the conditioning therapy and on days +2 +4, +6, +10, +20, +30 after alloHSCT. The IL-2 and IFN-γ serum concentrations were determined with use of ELISA assay. Before statistical analysis patients were divided into 4 groups according to the presence of acute GvHD and clinical manifestation of bacterial, viral or fungal infection.

Results

Group I – patients with neither acute GvHD nor infectious complications, n=15 (24%), group II – patients with infectious complications without acute GvHD, n=17 (27%), group III – patients with acute GvHD without infectious complications, n=9 (15%), and group IV – patients with both acute GvHD and infectious complications, n=21 (34%). IFN-γ levels were higher in group II than in other groups on days +20 (p=0.014) and +30 (p=0.008). The POST-HOC tests revealed lower levels of IFN-γ on day +30 in group I (p=0.039) and in group IV (p=0.017) as compared to group II. The concentration of IL-2 was undetectable in almost all patients at all studied time points.

Conclusion

Serum concentration of IFN-γ following alloHSCT gradually increases. High serum concentration of IFN-γ is related to infectious complications rather than to acute GvHD. Undetectable serum concentration of IL-2 in majority of patients prevents from drawing conclusions.