Multivariate analyses of immune reconstitution in children after allo-SCT: risk-estimation based on age-matched leukocyte sub-populations.

The speed of immune recovery after allo-SCT is of central importance to overcome infectious complications and relapse. To evaluate the immune reconstitution of pediatric patients concerning overall survival, we developed a three-component multivariate model and generated a reference domain of ellipsoidal shape on the basis of normal leukocyte subtype values of 100 healthy children and adolescents. The leukocyte subtypes include absolute nos. of leukocytes, CD14(+) monocytes, lymphocytes, CD3(+) T cells, CD3(+)CD4(+) helper T cells, CD3(+)CD8(+) cytotoxic T cells, CD3(-)CD56(+) natural killer-cells and CD19(+) B cells, all of which are correlated, thus, requiring the application of multivariate as opposed to multiple univariate modeling. According to their immune reconstitution, 32 pediatric patients post allo-SCT were classified into low-risk and high-risk groups on the basis of our new model. Therefore, we evaluated if the patients reached the ellipsoid of normal leukocyte sub-population values post SCT. We detected a significantly higher number of long-time survivors among the low-risk group compared with the high-risk group at days 200 (P=0.001) and 300 (P<0.0001). This is superior to our previously published univariate analysis. Combined with the clinical observation, a classification into risk groups based on an extended patient cohort may represent a predictor for complications.