Study On The Clinical And Immunological Characteristics Of 5 Patients With WHIM Syndrome And The Occurrence Of BO In RSV Infected HSCT Mice

PARTⅠCLINICAL AND IMMUNOLOGICAL CHARACTERISTICS OF 5 PATIENTS WITH WHIM SYNDROMEObjective:To analyze the clinical data and gene mutations of 5patients with WHIM syndrome,and to perform immunological phenotype analysis and functional verification to improve the diagnosis and treatment in clinical practice.Methods:Taking the 5 patients with genetically diagnosed WHIM syndrome who were treated in our hospital from January 2019 to November 2019 as the research objects,collected and summarized clinical data,analyzed the characteristics of gene mutations;peripheral blood were collected for the analysis of lymphocyte subsets;flow cytometry was used to detect the changes of CXCR4 expression in lymphocyte subsets before and after CXCL12 stimulation.Results:(1)Among the 5 patients with WHIM syndrome,there was one CXCR4(p.R334X)mutation,which has been reported as a hot spot mutation,and the other 4 cases were CXCR4(p.V344Lfs*27)mutations in the same family,which is new mutation.(2)All 5 patients had peripheral neutropenia,repeated respiratory tract infection.Among them,bone marrow cell examination of 3 patients showed myelokathexis,two patients had HPV infection-induced warts,and one case had hypogammaglobulinemia.(3)Analysis of lymphocyte subsets showed that all patients had disorders of lymphocyte subsets,The proportion and number of T and B cells in patients with CXCR4(p.R334X)mutation were significantly reduced.The analysis of 5 patients’T cell subsets showed that the naive T cell ratio decreased and the memory T cell ratio increased,the proportion of naive B cells and IgM~hii B cells increased,and the proportion of smB cells and memory B cells decreased.(4)The expression of CXCR4 in lymphocytes of patients were lower than that of the health control,and the CXCR4 internalization of 4 patients with new mutations were impaired after stimulation with CXCL12.Conclusion:This study summarized the clinical manifestations,immunological characteristics,and functional changes of a small cohort of WHIM patients,in which 4 cases from a same family with novel CXCR4 mutation(p.V344Lfs*27)may deepen the understanding of the immunodeficiency of these patients and provides guidance for the diagnosis and treatment of the disease in the future.PARTⅡ STUDY ON THE OCCURRENCE OF BO IN RSV INFECTED HSCT MICEObjective: To construct a allogeneic hematopoietic stem cell transplantation mouse model,infect the post-transplantation mice with respiratory syncytial virus,and monitor the occurrence of occlusive bronchiolitis,so as to clarify the relationship between respiratory syncytial virus infection and the occurrence of BO after hematopoietic stem cell transplantation.Methods: A mixture of bone marrow cells and spleen cells was transplanted into the myeloablatively treated mice via tail vein,and a mouse model of allogeneic hematopoietic stem cell transplantation was established.Flow cytometry was used to detect the chimerism rate at 3 and 7 weeks after transplantation.After transplantation,the mice were infected with RSV by nasal drip.The lung tissues were taken 5 days after infection to detect the infection status,and the lung tissues were subjected to pathological analysis 2 weeks and 2 months after infection.At the same time,the lung function of mice were detected by non-invasive lung functional spectroscopy before transplantation and 2 weeks after RSV infection.Results: The peripheral blood of the recipient rats were collected at 3 and 7 weeks after transplantation,and the chimerism rate were detected by flow cytometry above 90%,indicating successful implantation.5 days after RSV infection,the lung tissue homogenate of mice was inoculated into Hep-2 cells and see the typical lesion effect.Extracting RNA from the diseased cells for PCR can see the RSV F gene band at 239 bp,which all confirmed the successful RSV infection in the lung tissues.HE staining of lung tissue showed obvious inflammatory reaction 2 weeks and 2 months after RSV infection,and Masson staining of lung tissue showed a large amount of collagen fiber deposition 2 months after RSV infection.Lung function showed that Penh in RSV group mice was increased when the concentration of acetylcholine was 50mg/ml 2 weeks after infection.Conclusion: Mice with RSV infection after hematopoietic stem cell transplantation can cause severe lung lesions.With the prolonged infection time,pulmonary lesions did not decrease and fibrosis appeared,and airway resistance increased after infection.That is,RSV infection was closely related to the occurrence of BO after hematopoietic stem cell transplantation.