BACKGROUND:Growth factor is the key effect molecule that plays a role in platelet-rich plasma in clinical treatment.There are differences in the concentration of growth factor after different activators activate platelet-rich plasma,which is an important factor affecting clinical efficacy. OBJECTIVE:To analyze the influence of different activators on the mass concentration of growth factors in platelet-rich plasma. METHODS:Totally 12 healthy volunteers were recruited to collect EDTA-K2 anticoagulant venous blood.Secondary centrifugation was used to prepare platelet-rich plasma.The difference in mass concentrations of growth factors was compared between venous blood and platelet-rich plasma.The platelet-rich plasma was mixed with four activators(normal saline,thrombin,calcium gluconate,calcium gluconate+thrombin)according to the volume ratio of 10:1,and incubated in a constant temperature water bath at 37 °C for 30 minutes.After centrifugation,the supernatant was extracted and the mass concentration of growth factor was detected.The bacterial growth in supernatant was measured by blood agar plate.Pearson correlation was used to analyze the correlation between different activators and the mass concentration of growth factor in platelet-rich plasma,and the correlation between the value of thrombocytometer and the mass concentration of growth factors in platelet-rich plasma. RESULTS AND CONCLUSION:(1)The mass concentrations of platelet-derived growth factor-BB,platelet-derived growth factor-AB,vascular endothelial growth factor,and epidermal growth factor in platelet-rich plasma were 8.7,22.2,2.3,and 2.8 times of those in venous blood,respectively(P<0.05).(2)Compared with normal saline group,the mass concentrations of platelet-derived growth factor BB,platelet-derived growth factor AB,vascular endothelial growth factor,and epidermal growth factor were increased in the thrombin group,calcium gluconate group,and calcium gluconate+thrombin group(P<0.05).The mass concentration of platelet-derived growth factor BB in the thrombin group and calcium gluconate group was higher than that in the calcium gluconate+thrombin group(P<0.05),and the mass concentration of platelet-derived growth factor AB in the thrombin group was higher than that in the calcium gluconate group and calcium gluconate+thrombin group(P<0.05).Epidermal growth factor mass concentration in the thrombin group was lower than that in the calcium gluconate group and calcium gluconate+thrombin group(P<0.05).(3)The results of blood agar plate test showed no bacterial growth in the supernatant of the four groups.(4)Pearson correlation analysis showed that the mass concentration of platelet-derived growth factor BB in platelet-rich plasma was strongly positively correlated with thrombin(r=0.683,P<0.05),and the mass concentration of vascular endothelial growth factor was strongly positively correlated with thrombin,calcium gluconate,calcium gluconate+thrombin stimulant(r=0.730,0.789,0.686,P<0.05).There was no correlation between the value of thrombocytometer and the mass concentration of four kinds of growth factors(P>0.05).(5)The results suggest that different activators have an impact on the concentration of growth factors in platelet-rich plasma.It is suggested to choose different activators to improve clinical efficacy according to different growth factor mass concentrations and treatment needs.

Objective To study the changes in serum immunoglobulin levels in children with thalassemia who undergo repeated blood transfusions and explore their correlation with delayed hemolytic transfusion reactions(DHTR).Methods Serum samples from children with thalassemia who received blood transfusion treatment from June 2022 to April 2023(ob-servation group)and healthy children who underwent physical examination(control group)in our hospital were collected.The levels of serum immunoglobulins(IgG subtype,IgM,IgA,IgE and IgD)were detected using flow cytometry CBA multi-factor quantitative detection technology,and the differences between the two groups were compared.The children were divided into 4 groups according to different transfusion numbers:≤10 numbers,11-30 numbers,31-50 numbers and＞50 numbers,and the differences between different blood transfusion numbers and serum immunoglobulin levels in each group were compared using one-way analysis of variance(ANOVA).Children with thalassemia with DHTR were in the hemolysis group,and children with thalassemia who did not experience DHTR were in the non-hemolysis group.The changes in serum immunoglobulins(IgG subtypes,IgM,IgA,IgE and IgD)between the two groups were compared to explore the correlation between serum immunoglobulins in thalassemia children with repeated transfusion and DHTR.Results The levels of IgG1,IgG3,IgG4 and IgA in the observation group were significantly higher than those in the control group,with the increase of(2.07±2.12),(0.67±2.03),(0.30±0.37)and(6.04±11.40)mg/mL,respectively,while the level of IgD in observation group was significantly lower than that in the control group,with a decrease of(0.03±0.01)mg/mL,P＜0.05.No significant difference was noticed in IgG2,IgM and IgE between the groups(P＞0.05).IgG1 and IgG4 both significantly increased with the number of blood transfusions.The IgG1 in the 4 groups increased sequentially as(0.30±0.62),(0.41±0.51)and(3.60±3.48)mg/mL,and IgG4 increased sequentially as(0.12±0.13),(0.22±0.07)and(0.21±0.38)mg/mL.IgG2,IgM and IgD showed a significant decrease,with IgG 2,IgM,and IgD in four groups decreased as(0.91±1.50),(0.14±0.10)and(0.05±0.05)mg/mL,respectively,showing significant differences with the number of blood transfusions(P＜0.05).No sig-nificant difference was found in IgG3,IgA and IgE with different number of transfusions(P＞0.05).IgG1,IgG3 and IgG4 in the hemolysis group were significantly higher than those in the non-hemolysis group,with an increase of(4.44±3.41),(0.73±1.26)and(0.52±0.40),respectively(P＜0.05).IgD in the hemolysis group was significantly lower than that in the non-hemolysis group,with a decrease of(0.00±0.06)mg/mL,P＜0.05.No significance was noticed in IgG2,IgM,IgA and IgE between the hemolysis group and the non-hemolysis group(P＞0.05).Conclusion The serum immunoglobulin levels of children with thalassemia who undergo repeated blood transfusions are abnormal.There are differences in correlation between the number of blood transfusions and serum immunoglobulin levels among children with thalassemia who undergo repeated blood transfusions.The relevant serum immunoglobulins for DHTR in children with thalassemia who undergo repeated blood transfusions are IgG1,IgG3 and IgG4.

【Objective】 To investigate the changes in cellular immunity (peripheral blood lymphocyte subsets) and humoral immunity (serum immunoglobulin and ferritin) status among children with thalassemia who received repeated transfusions in Yunnan. 【Methods】 Forty-six children with thalassemia who underwent repeated blood transfusions from January 2020 to October 2022 were selected as the observation group. Forty children with thalassemia who did not receive blood transfusion were included in control group 1, and 46 healthy children underwent physical examination were included in control group 2. The differences in lymphocyte subsets, serum immunoglobulin levels and ferritin concentrations were compared among the three groups. 【Results】 For lymphocyte subsets: CD3⁺, CD4⁺ and CD4⁺/CD8⁺ in the observation group was lower than the control group 1 and 2: 57.60±8.36 vs 64.57±7.56 vs 66.58±5.65, 33.16±5.67 vs 38.62±8.36 vs 38.62±6.41 and 1.49±0.09 vs 2.32±0.15 vs 2.13±0.16, respectively; CD16⁺ CD56⁺ in the observation group was lower than the control group 2: 11.21±5.06 vs 16.70±7.92; CD8⁺ in the observation group was higher than control group 1 and control group 2: 26.63± 1.75 vs 20.60±1.43 vs 18.92±0.84; CD19⁺ in the observation group was higher than the control group 2: 24.06±6.42 vs 19.67 ±8.42, P<0.05, but no significant difference was noticed between the two control groups(P>0.05). For serum immunoglobulin and ferritin: IgG and ferritin in the observation group were higher than control group 1 and control group 2: 10.59±3.88 vs 7.02±3.88 vs 5.58±1.98 and 2 037.37±1 377.59 vs 72.63±56.71 vs 59.48±33.88. IgA in the observation group was higher than the control group 2: 1.06±0.92 vs 0.39±0.32(P<0.05), but no significant difference was noticed between the two control groups (P>0.05). The difference of IgM and IgE between the three groups was not significant (P > 0. 05). 【Conclusion】 The proportion of lymphocyte subsets in thalassemia children with repeated blood transfusion was imbalanced,and the level of immunoglobulin in humoral immunity was abnormal.

【Objective】 To share the experience of autologous platelet-rich plasma(PRP) combined therapy in successful treatment of refractory osteomyelitis with fractures in children. 【Methods】 One case of refractory osteomyelitis with fracture in children failed to respond to traditional treatment for more than 14 months. A total of 20 mL of whole blood was collected from the child, and 6 mL of PRP with 4 to 5 times concentration was prepared by secondary centrifugation. To prepare 2 cm×2 cm platelet concentrate gel (PG), 3 mL of PRP was mixed with a 0.3 mL activator which was then covered with an absorbable dressing. A three-way tube sprayed the remaining 3 mL of PRP and 0.3 mL activator into the surrounding tissues. 【Results】 The X-ray film of the patient followed up for 1 week showed that the fracture line was blurred, and the fracture end had obvious callus formation. The X-ray film reexamination at 4 months showed that the fracture end healed well, the fracture surface healed, and the osteomyelitis healed. 【Conclusion】 Autologous PRP has a good effect in the treatment of refractory osteomyelitis combined with fracture in children, which can provide a new method for clinical treatment.