[A control study of steroid withdrawal protection strategy after kidney transplantation in children]

Objective: To study the influence of steroid withdrawal protection strategy on height growth in pediatric patients after kidney transplantation. Methods: The prospective cohort study enrolled 40 stage 5 chronic kidney disease children receiving kidney transplantation from July 2017 to September 2022 at Guangzhou Women and Children's Medical Center. Based on the primary preoperative disease, patients with immune abnormality-associated glomerular diseases or unknown causes were assigned to the steroid maintenance group, in which patients received steroid tapering within 3 months after surgery to a maintenance dose of 2.5 to 5.0 mg/d. While patients with hereditary kidney disease or congenital urinary malformations were assigned to the steroid withdrawal group, in which patients had steroids tapered off within 3 months. The characteristics of height catch-up growth and clinical data were compared between the 2 groups at baseline, 6, 12, 18 and 24 months after kidney transplantation. T-test, repeated measurement of variance analysis, Mann-Whitney U test, and Fisher exact test were used for the comparison between the 2 groups. Results: Among the 40 children, 17 were males, 23 were females, 25 were in the steroid withdraw group ((7.8±2.8) years old when receiving kidney transplantation) and 15 cases were in the steroid maintenance group ((7.6±3.5) years old when receiving kidney transplantation). The study population was followed up for (26±12) months. The total dose per unit body weight of steroids in the steroid withdrawal group was lower than that in the steroid maintenance group ((0.13±0.06) vs. (0.36±0.19) mg/(kg·d), t=5.83, P<0.001). The height catch-up rate (ΔHtSDS) in the first year after kidney transplantation in the steroid withdraw and steroid maintenance groups was 1.0 (0.7, 1.4) and 0.4 (0.1, 1.0), respectively; in the second year, the ΔHtSDS in the steroid withdraw group was significantly higher than that in the steroid maintenance group (1.1 (0.2, 1.7) vs. 0.3 (0, 0.8), U=28.00, P=0.039). The HtSDS in the steroid withdrawal group at the five follow-up time points was -2.5±0.8, -2.0±0.8, -1.5±0.8, -1.3±0.9 and -0.5±0.3, respectively, while in the steroid maintenance was -2.4±1.3, -2.2±1.1, -2.0±1.0, -1.8±1.0 and -1.6±1.0, respectively. There were statistically significant differences in HtSDS at different follow-up time points in both 2 groups (F=19.81, P<0.01), but no statistical differences in overall impact between the 2 groups (F=1.13, P=0.204). The steroid treatment was interaction with the increase of follow-up time (F=3.62, P=0.009). At the 24^th month after transplantation, the HtSDS in the steroid withdrawal group was significantly higher than that in the steroid maintenance group (P=0.047). Six patients in the steroid withdrawal group experienced antibody-mediated immune rejection (AMR), while 3 did in the steroid maintenance group. Moreover, there was no significant difference in AMR between the two groups (χ²=0.06, P=0.814). Conclusion: The steroid withdrawal protection strategy favors the height catch-up growth in pediatric patients after kidney transplantation and does not increase the risk of postoperative antibody-mediated immune rejection.