Central serous chorioretinopathy(CSC)is a macular disease predominantly affecting young to middle-aged adults, characterized by serous retinal detachment in the posterior pole, leading to symptoms such as decreased central vision, visual distortion, and color changes. The disease has a certain degree of self-limitation but can recur. The pathogenesis is still uncertain and the treatment is controversial. Commonly used treatments include medication, retinal laser, photodynamic therapy(PDT)and vitreous anti-vascular endothelial growth factor(VEGF)therapy which have emerged in recent years, but the treatment of recurrent CSC is still tricky. The purpose of this article is to review the current therapeutic approaches regarding CSC, with a view to providing a reference for clinical treatment.

【Objective】 To identify the specificity of alloantibody against high-frequency antigens in one case suffering with severe hemolytic diseases of the fetus and newborn (HDFN) and to screen for matching blood for transfusion. 【Methods】 The HDFN test and the antibody serological identification tests in the mother were performed. Several common high frequency antigens of maternal red blood cells (RBCs) were determined. IgG subtype coated on the RBCs of the newborn was determined. The phagocytic efficiency of the antibody was tested using the monocyte phagocytosis of sensitized erythrocyte by flow cytometry in vitro. Sanger sequencing of DI gene was performed in the mother, father and mother’s brother. The diluted maternal plasma was used for large scale screening of matching blood using IAT in Coomb’s gel card. 【Results】 Di(b-) phenotype was identified in the mother of the newborn and anti-Di^b (titer: 512) related HDN was detected in the newborn. IgG1 and IgG2 subtypes of anti-Di^b were detected and the rate of monocyte phagocytosis was 88.83%(74.7/84.09). The compatible blood was not detected in the maternal relatives. Subsequently, the newborn received the matching RBCs of two Di(b-) donors identified from 5 520 blood donors and discharged from the hospital. We screened out 17 Di(b-) donors out of 51 334 blood donors, indicating that the distribution frequency of Di(b-) among blood donors in Guangzhou was about 0.033% (17/51 334). 【Conclusion】 By serology and molecular biology methods, the newborn was identified with HDFN caused by anti-Di^b, and an effective large-scale screening method for Di (b -) rare blood types was established to find matching blood, which supported the establishment of rare Di(b-) blood database.

Objective To elucidate the prediction ability of monocyte monolayer assay(MMA)used in hemolytic dis-ease of fetus and newborn(HDFN)caused by IgG anti-M.Methods Plasma from eight pregnant women containing IgG an-ti-M were collected,and were divided into two groups(4 cases with HDFN,with severe clinical symptoms such as fetal hy-drops,and 4 cases without HDFN)according to the clinical outcomes.M antigen positive cells were sensitized with dithioth-reitol(DTT)treated plasma from eight pregnant women respectively.MMA was performed by coincubation with monocytes and sensitized M cells,along with negative and positive control set up.T-test was conducted to compare the difference in phagocytic efficiency between two groups.Results The phagocytic efficiency in group with HDFN were 15.37%,13.05%,9.17%and 24.50%respectively,with the mean value of 15.52%,while the group without HDFN were 8.74%,11.07%,5.12%and 6.23%respectively,with the mean value of 7.79%.There was no significant difference in phagocytic efficiency between two groups(P>0.05).The mean values of both groups were not significantly different from the negative control(P>0.05),but both were significantly lower than positive control(P<0.05).Conclusion The low phagocytic efficiency couldn't convince that the MMA is an effective predictor for the HDFN caused by IgG anti-M,indicating that another mech-anism might be responsible for it rather than monocyte phagocytosis.The assessment of the peak systolic velocity in middle cerebral artery of the fetal should be considered in the management for pregnant women who produce IgG anti-M to estimate the situation of fetal anemia.

Objective:To develop a genotyping method for the Junior blood type and report on a rare blood type with Jr(a-).Methods:Healthy O-type RhD+ volunteer donors of the Shenzhen Blood Center from January to May 2021 ( n=1 568) and a pedigree with difficult cross-matching ( n=3) were selected as the study subjects. Serological methods were used for proband′s blood type identification, unexpected antibody identification, and antibody titer determination. Polymerase chain reaction-sequence specific primer (PCR-SSP) method was used for typing the proband′s RHD gene. ABCG2 gene coding region sequencing and a PCR-SSP genotyping method were established for determining the genotypes of the proband and his family members and screening of Jra antigen-negative rare blood type among the 1 568 blood donors. Results:The proband′s ABO and RhD blood types were respectively determined as B and partial D (RHDDVI.3/RHD01N.01), Junior blood type Jra antigen was negative, and plasma had contained anti-D and anti-Jra. Sequencing of the ABCG2 gene revealed that the proband′s genotype was ABGG201N.01/ABGG201N.01 [homozygous c. 376C>T (p.Gln126X) variants], which is the most common Jr(a-) blood type allele in the Asian population. Screening of the voluntary blood donors has detected no Jr(a-) rare blood type. Statistical analysis of the heterozygotes suggested that the allelic frequency for ABCG2*01N.01 (c.376T) was 0.45%, and the frequency of Jr(a-) rare blood type with this molecular background was about 0.2‰. Conclusion:A very rare case of partial DVI.3 type and Jr(a-) rare blood type has been identified. And a method for identifying the Junior blood type through sequencing the coding regions of the ABCG2 gene and PCR-SSP has been established.

Objective To construct hns gene overexpression strains of Burkholderia thailandensis BPM,and explore the effects of hns overexpression on bacterial growth,motility,biofilm formation ability and susceptibility to antimicrobial drugs.Methods The hns genes 03253 and 05307 were respectively cloned into the expression vector pTAC-Cm to yield recombinant vectors pTAC-03253 and pTAC-05307.Then the 2 types of plasmids were electroporated into the BPM competent strain to obtain recombinant strains,and their phenotypic changes in growth,motility,biofilm,and drug sensitivity were detected.Results The strains of hns overexpression were successful constructed,and they presented significantly inhibited growth and motility,markedly enhanced ability to form biofilms,decreased sensitivity to levofloxacin and minocycline when compared with the wild-type BPM strain.Conclusion H-NS protein plays an important role in the regulation of virulence and drug resistance in Burkholderia thailandensis BPM,and can become a new target for the treatment of infections caused by Burkholderia thailandensis.

【Objective】 To solve the difficulty of RhD blood group typing in a patient with double population(DP) of red blood cells for RhD antigen by serological and genotyping analysis. 【Methods】 Separation of the two populations of red blood cells of the patient was performed using capillary centrifugation method. ABO, RhD and RhCE typing, direct anti-human globulin test (DAT), irregular antibody screening, antibody identification and blood crossmatching of the patient were conducted using the standard serological methods. The hybrid Rhesus zygosity analysis of the RHD gene was performed by PCR-RFLP method. RHD and RHCE genotype of the patients were identified by PCR-SSP method. 【Results】 The patient was B type but with DP of red blood cells for RhD, Rhc and RhE antigens. DAT of the patient was positive and the alloanti-D was detected in serum. The RHD zygosity was D-/D- homozygote. PCR-SSP testing showed the RHD gene deletion (RHD * 01N. 01/01N.01 genotype) and Ccee of RHCE genotype in the patient, which was consistent with RHD zygosity analysis. 【Conclusion】 This is a special case with D-negative phenotype which was wrongly detected as D-positive type after D-positive red blood cells transfusion in emergency. When the DP of red cells for D antigen encountered like this case, the RhD typing can be accurately determined by using RHD genotyping analysis to provide strong evidence to the clinical blood transfusion.

【Objective】 To identify the antibody specificity in a pregnant women who had no history of blood transfusion but presented the antibodies against high-frequency antigens. 【Methods】 ABO, RhD blood group antigens were identified by saline. Antibody screening and identification were performed by saline and indirect Coomb’s technique. Further antibody identification tests were conducted using papain, trypsin and chymotrypsin-treated cells. Antibody titer in serum was tested. PCR amplification and sequencing analysis of 16 exons of ABCG2 gene were conducted. 【Results】 The blood type of the patient were B, RhD positive. The serum reacted with antibody screening/identified cells by indirect antiglobin test(both 2+ ) but not by saline. The agglutination was enhanced after papain treatment (4+ ), but remained unchanged after trypsin and chymotrypsin treatment (2+ ). The IgG titer was 1∶2. The sequencing analysis of ABCG2 gene revealed a homozygous nonsense mutation(c.376C>T, p. Gln126X) in exon 4 of the women. 【Conclusion】 In this case, the development of anti-Jr^a in Jr(a-) mother was stimulated by mother-child serology incompatibility during pregnancy.

【Objective】 To establish an experimental method for detecting phagocytosis of sensitized red blood cells in vitro by flow cytometry. 【Methods】 Mononuclear cells were isolated from the peripheral blood of blood donors and cultured in a cell incubator for 1 hour, and then adherent monocytes were isolated and obtained. Di^b-positive red blood cells (RBCs) were labeled with PKH26 and then sensitized with IgG anti-Di^b. The sensitized RBCs were added to monocytes for in vitro phagocytosis assay. Monocytes were labeled with FITC anti-human CD14, then phagocytosis was measured by flow cytometry, and the phagocytic efficiency was calculated. The method was used to detect the phagocytic efficiency of monocytes on human IgG anti-D sensitized RBCs with different titers. 【Results】 The phagocytic efficiency of monocytes was averaged at 5% (1.2%~7.6%, SD 3.30) versus 81% (71.4%~92.7%, SD 8.65) in the negative versus positive control group, respectively. Phagocytic activity of monocytes mediated by anti-D was correlated with the antibody titer. The phagocytosis efficiency was within 10% when the antibody titer was lower than 32 and increased sharply when the titer was between 32 to 128, it entered a plateau and stabilized at 80% at the titer above 256. 【Conclusion】 A detection platform for detecting phagocytosis-sensitized RBCs in vitro by flow cytometry has been successfully established. It can be used to assess the clinical significance of red blood cell allotype or autologous IgG antibodies.

【Objective】 To establish a high-throughput detection method for ABCG2^*376T allele of Jr(a-), and apply it to the study of the frequency of this allele in the Chinese population. 【Methods】 The specific primers were designed and synthesized, the sample carrying homozygous ABCG2^*376T alleles, obtained in the previous study, was used as the homozygous positive control, and the sample carrying heterozygous allele as the heterozygous positive control. The wild-type sample was used as a negative control, and a high-resolution melting curve(HRM) method for detecting this allele was established. The established method was used to screen DNA samples from blood donors in Guangzhou, and the samples carrying ABCG2^*376T alleles were sequenced to confirm the accuracy of the HRM method. 【Results】 A HRM method, which can detect ABCG2^*376T allele and accurately type homozygotes and heterozygotes at the same time, had been established successfully. Fifteen individuals with heterozygous alleles were screened out of 1 560 blood donors in Guangzhou, while none homozygous allele was detected. 【Conclusion】 The HRM method can be used to accurately screen and type ABCG2^*376T allele. The frequency of this allele in Chinese population is about 0.48%(15/3120).

Objective:To investigate the factors affecting phenotypes in the patients of methylmalonic acidemia combined with homocysteinemia cblC type with MMACHC c. 609G>A homologous variant. Methods:A retrospective study on the clinical manifestations, complications, treatment, and outcome in 164patients of cblC type with MMACHC c. 609G>A homologous variant was conducted.The patients were diagnosed by biochemical and genetic analysisfrom January 1998 to December 2020. Results:Among the 164 patients, 2 cases were prenatally diagnosed and began treatment after birth. They are 3 and 12 years old with normal physical and mental development. Twenty-one cases were diagnosed by newborn screening. Among them, 15 cases had with normal development. They were treated fromthe age of two weeks at the asymptomatic period. Six cases began treatment aged 1 to 3 months after onset. Their development was delayed. One hundred and forty-one cases were clinically diagnosed. Their onset age ranges from a few minutes after birth to 6 years old. 110 cases had early-onset (78.0%). 31 cases had late-onset (22.0%). Five of them died. 24 patients lost to follow-up. Of the 141 clinically diagnosed patients, 130 (92.2%) with psychomotor retardation, 69 (48.9%) with epilepsy, 39 (27.7%) with anemia, 30 (21.3%) had visual impairment, 27 (19.1%) had hydrocephalus, 26 (18.4%) had feeding difficulties, 7 (5.0%) with liver damage, and 5 (3.5%) with metabolic syndrome. The frequency of hydrocephalus and seizures was significantly higher in the early-onset group. The urinary methylmalonic acid increased significantly in the patients with epilepsy. During the long-term follow-up, the level of plasma total homocysteine in the seizure-uncontrolled group was significantly higher than that in the seizure-controlled group, the difference had a statistical significance ( P<0.05). Conclusion:Most of the patients with MMACHC c. 609G>A homozygous variant had early-onset disease, with a high mortality and disability rate. If not treated in time, it will lead to neurological damage, resulting in epilepsy, mental retardation, hydrocephalus, and multiple organ damage. Pre-symptomatic diagnosis and treatment are crucial to prevent irreversible neurological damage. Neonatal screening and prenatal diagnosis are important to improve the outcome of the patients.