Development and validation of ID-LC-MS/MS method for L-tryptophan and its metabolites / 中华检验医学杂志

Objective:To establish an isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method for the determination of L-tryptophan and its metabolites in serum.Methods:The methodology was established and evaluated using serum samples collected from 166 healthy subjects undergoing physical examinations at West China Hospital from November 2022 to January 2023 were collected. Isotope-labeled markers of L-tryptophan (Trp), L-kynurenine (Kyn), and kynurenic acid (KA) were used as internal standards. After protein precipitation treatment of serum samples, LC-MS/MS was used to determine Trp, Kyn, and KA simultaneously. The selectivity, specificity, linearity, detection limit (LOD), quantification limit (LOQ), carry-over, precision, recovery rate, matrix effect, and dilution integrity of the method were evaluated.Results:The linearity of Trp, Kyn, and KA was demonstrated to be 0.999. The LODs were 0.10 μmol/L, 0.01 μmol/L and 1.00 nmol/L, respectively. The LOQs were 0.20 μmol/L, 0.04 μmol/L and 2.00 nmol/L, respectively. The intra-batch precision and inter-batch precision were below<10%. The average recovery rate and the relative matrix effect were all about 100%. The samples over the upper limit of quantitation can be diluted up to 16 times. The Trp concentration, Kyn concentration, KA concentration, Kyn/Trp ratio, and KA/Kyn ratio in serum of healthy subjects were 59.55±10.92 μmol/L, 1.85±0.43 μmol/L, 39.89±17.93 nmol/L, (31.64±8.19)×10 -3 and 21.51±6.72, respectively. Conclusion:An ID-LC-MS/MS method was successfully established for the quantitative determination of Trp, Kyn, and KA in serum. The method proved to be simple, rapid, sensitive, accurate, and reliable, providing robust support for clinical research related to these analytes.

Targeted therapy of post-transplant lymphoproliferative disease / 中华实用儿科临床杂志

Post-transplant lymphoproliferative disease(PTLD) results from the uncontrolled proliferation of lymphocytes after hematopoietic stem cell transplantation and solid organ transplantation.PTLD greatly reduces the survival of both patients and grafts.The treatments for PTLD include reducing the use of immunosuppressive agents, chemotherapy, EB virus-specific cytotoxic T lymphocytes (CTL), B lymphocyte depletion therapy, targeted inhibitors, etc.However, all of them have shortages.Specific biological target drugs aiming at a certain link in the pathogenesis of PTLD show a good curative effect and small adverse reactions, and thus serve as new options for its prevention and treatment.Because of the limited data, clinical studies are still needed to confirm these drugs.In this article, the application of targeted therapy in the treatment of PTLD was summarized.

A case report of BCL11B mutation induced neurodevelopmental disorder and literature review / 中华儿科杂志

Objective@#To analyze the clinical , immunological and genetic features of a child with BCL11B mutation induced neurodevelopmental disorder.@*Methods@#The clinical data and genetic test of a child with BCL11B mutation hospitalized in the Department of Rheumatology and Immunology in Children′s Hospital of Chongqing Medical University in December 2018 were extracted and analyzed. The literature was searched with "BCL11B mutation" and "immunodeficiency 49" as key words in Chinese databases and Pubmed until January 2019 was reviewed.@*Results@#A male patient aged 3 years and 11 months with facial dysmorphisms and delayed language and motor development was admitted due to neurodevelopmental retardation over two years. Laboratory tests showed normal human immunoglobulin (IgG 12.90 g/L, IgA 1.02 g/L, IgM 1.15 g/L, IgE 532 000 U/L), Trec (228) and proliferation of T and B cells. The lymphocyte subsets revealeda reduced percentage of B cells (0.108) but normal absolute numbers (0.574×10-3/L), and an increased percentage (0.828) as well as absolute numbers (4.415×10-3/L) of T cells. A heterozygous BCL11B mutation was detected by sanger sequencing, showing a de novo frameshift mutation c.1887_c.1893delCGGCGGG in exon 4. Two papers were found which were all in English, with total of 14 patients(13 patients with complete information). Thirteen mutations were reposed, including 7 frameshift, 2 nonsense, 2 missense, and 2 chromosomal rearrangements; Thirteen patients had heterozygous mutations. All patients had delayed language and motor development and facial dysplasia which were mainly hypertelorism, thin eyebrows and small palpebral fissures. Some patients had dental anomalies, ametropia and allergy, and a few were combined with immune impairment, but without overt signs of immunodeficiency. Only one patient had multisystem anomalies and profound immune deficiency.@*Conclusions@#BCL11B is essential for development of the nervous and the immune system. In this study, the de novo mutation of BCL11B gene resulted in neurodevelopmental and immunological disorders.

Clinical and immunological analysis of the patient with autoimmunity due to germline STAT3 gain-of-function mutation / 中华儿科杂志

Objective@#To investigate the clinical and immunological laboratory features and gene mutation in a female patient who carried a germline gain-of-function mutation in STAT3.@*Method@#A patient with lymphadenopathy and pancytopenia, visited the Department of Rheumatology and Immunology of Children′s Hospital of Chongqing Medical University in May 2016. The clinical and laboratory characteristics, results of immunophenotyping and exome sequencing were analyzed retrospectively and related literature was reviewed.@*Result@#The patient was a four years old girl. The clinical manifestation consisted of autoimmune pancytopenia, lymphadenopathy and recurrent infections. Multiple exams showed that peripheral blood leukocyte count was (2.2-4.9)×109/L, red blood cell count was (2.09-5.75)×109/L, hemoglobin level was 64-165 g/L, platelet count was (52-138) ×109/L. Percentages of lymphocyte subsets showed that CD3+ T lymphocyte was 0.716 0 (CD4+ T lymphocyte was 0.326 0, CD8+ T lymphocyte was 0.323 0 and CD4- CD8-T TCRαβ+ lymphocyte was 0.029 0), CD19+ B lymphocyte was 0.235 0 (transitional B was 0.004 3), NK was 0.032 0. Percentages of CD4+ T lymphocyte release IL-4, IFN-γ, IL-17 and IL-21 were 0.014 9, 0.213, 0.024 0 and 0.021 0, respectively. Lymphocyte proliferation function and TCRVβ diversity were normal. The serum immunoglobulin levels were 16.4 g/L (IgG), 1.53 g/L (IgA), 3.99 g/L (IgM) and 3.20 kU/L (IgE). The patient carried a missense variant in the 21st exon of STAT3, c. 1974G>C, p.K658N, which was previously described as a gain-of-function mutation. The patient was treated with methylprednisolone and prednisone intermittently. There were significant improvements of hepatosplenomegaly, lymphadenopathy and pancytopenia. We searched internal database and literature for cases with gain-of-function mutations in STAT3. A total of 19 cases were identified, all were non-Chinese. Among 16 cases who had clinical data, age of onset of 11 patients was less than 5 years. 14 cases had autoimmune hemolytic anemia, autoimmune thrombocytopenia or autoimmune neutropenia. Twelve patients had lymphadenopathy while 11 had infections and 5 had endocrine abnormalities.@*Conclusion@#The patient with Primary immunodeficiency disease (PID) due to gain-of-function mutation in STAT3 gene often has early-onset autoimmune disorders, lymphadenopathy and recurrent infections. Since the routine immunological examination may be normal or slightly abnormal, comprehensive evaluation of immune function should be done. Genetic testing ultimately helps to confirm the diagnosis.

Clinical and immunological analysis of patients with activated phosphoinositide 3-kinase δ syndrome resulting from PIK3CD mutation / 中华儿科杂志

Objective@#To explore the clinical and immunological features, gene mutations, treatment and prognosis in patients with activated phosphoinositide 3-kinase δ syndrome (APDS) caused by PIK3CD gene heterozygous germline mutation.@*Method@#The data of clinical, immunological phenotype, treatment, and prognosis of 15 patients with APDS, who visited Children′s Hospital of Chongqing Medical University, Peking Union Medical College Hospital, and Shenzhen Children′s Hospital from June 2014 to November 2016, were collected and analyzed.@*Result@#Of the 15 patients, 11 were males, remaining 4 patients were females. The median age of disease onset was 1 year, and median age at diagnosis was 4 years and 4 months. All patients had the de novo heterozygous germline mutation in PIK3CD (c. 3061G>A, p. E1021K). The common initial symptoms were respiratory infections, including pneumonia (12 cases) , bronchiectasis (5 cases). Other common clinical manifestations were recurrent and chronic diarrhea (11 cases), Epstein-Barr virus (EBV) and/or cytomegalovirus (CMV) viremia (10 cases), hepatosplenomegaly (13 cases), and lymphadenopathy (10 cases). The main immunological features were increased IgM (11 cases), decreased IgG (6 cases), decreased numbers of CD4+ T cell (7 cases) especially naïve CD4+ T cell (9 cases), reduced numbers of B cells (11 cases) particularly naïve B cells (9 cases), increased numbers of transitional B cells (5 cases) and CD8+ terminally differentiated effector memory T cells (5 cases). After 1-29 months follow up, 13 of the 15 cases remain survived, of whom 5 cases received regular intravenous immunoglobulin (IVIG) therapy, with reduced frequency of infections and improved severity of infections; of whom 3 cases received oral rapamycin therapy at the dosage of 1 mg/ (m2·d) and with a decrease in nonneoplastic lymphoproliferation.@*Conclusion@#E1021K is a hotspot for mutation in the PIK3CD gene in patients with APDS. Regular IVIG can improve their quality of life. Targetel treatment with rapamycin could mitigate hepatosplenomegaly.

DNA repair defects in primary immunodeficiency diseases / 中华实用儿科临床杂志

DNA repair defects are classified as combined immunodeficiencies with associated or syndromic features,including 8 kinds of diseases with mutation of 9 pathogenic gene (ATM,MRE11,NBS1,BLM,RNF168,DNMT3B,ZBTB24,PMS2,MCM4),which are mainly autosomal recessive and monogenic inheritance.This article mainly reviews the pathogenesis,clinical manifestation,immunophenotype,and diagnosis of these diseases.