Infection prevention and control of bedside blood purification treatment in patients with COVID-19 / 北京大学学报(医学版)

OBJECTIVE@#To explore the infection prevention and control strategy of bedside blood purification treatment in corona virus disease 2019 (COVID-19) isolation ward, and to evaluate the effect of infection prevention and control management measures.@*METHODS@#We summarized and analyzed the clinical features, infection status, outcome and infection prevention and control measures of bedside blood purification treatment patients in COVID-19 isolation ward from February 8, 2020 to March 31, 2020, analyzed the COVID-19 cross-infection between the patients and medical staffs, and the blood-borne pathogens cross-infection situation between the patients, and analyzed the effect of bundle prevention and control measures in controlling the occurrence and spread of cross-infection.@*RESULTS@#A total of 101 COVID-19 patients were hospitalized in this COVID-19 isolation ward, of whom 10 patients (9.90%) received bedside blood purification treatment and the blood purification treatment method was continuous hemodialysis filtration (CVVHDF), and the 10 patients received 79 times of blood purification treatment in total. The prevention and control management measures adopted included divisional isolation, patient behavior isolation and patient placement, operator personal protection and hand hygiene, dialysis waste fluid disposal, isolation room air purification, object surfaces, medical devices and medical fabrics dis-infection management. There were no occurrence and spread of COVID-19 in the medical healthcare workers and blood-borne pathogens cross-infection in the patients. And all the twice throat swabs (two sampling interval > 1 day) of the medical staffs in COVID-19 virus nucleic acid test were negative. The 2 suspected COVID-19 patients' throat swab virus nucleic acid test and the COVID-19 IgG, IgM were always both negative, the chest CT showed no viral pneumonia.@*CONCLUSION@#Bedside blood purification treatment in the COVID-19 isolation ward, the occurrence and spread of healthcare associated infection can be effectively controlled through effective infection prevention and control management, including divisional isolation, patient behavior isolation and patient placement, operator personal protection and hand hygiene, dialysis waste fluid disposal, isolation room's air purification, object surfaces, medical devices and medical fabrics disinfection, which can provide experience for diagnosis, treatment and prevention and control of patients in the respiratory infectious disease ward.

Human cytomegalovirus induces apoptosis of human promyelocytic leukemic cells via direct infection in vitro / 中国实验血液学杂志

The study was purposed to investigate the proliferation and the suppression effect of human cytomegalovirus (hCMV) on human promyelocyte cell line HL-60, and to study whether hCMV can induce apoptosis of HL-60 via direct infection in vitro and its mechanism. Promyelocyte cell line HL-60 and hCMV AD169 strain were co-cultured. PCR was used to detect the direct infection of HL-60 cells by hCMV IEA expression. The apoptosis cells were analyzed by morphologic observation, DNA ladder formation, flow cytometry with Annexin V/PI stain. The results indicated that hCMV AD169 suppressed the differentiation and proliferation of HL-60 cells in vitro significantly (P < 0.05). The suppression was dose-dependent. hCMV DNA was successfully detected in HL-60 cells of viral infection groups by PCR. The apoptotic cells were confirmed by morphologic observation and DNA ladder formation. The results of flow cytometry showed that the percentage of apoptotic cells increased along with the increase of hCMV titer and the time after infection. It is concluded that the promyelocyte can be infected directly by hCMV AD169 strain. hCMV AD169 strain inhibited the differentiation and proliferation of promyelocyte. The apoptosis of HL-60 cells can be induced by hCMV infection. With the increase of viral infectious titer and the time after infection, the percentage of apoptotic cells also increase and produce in dose-dependent and time- dependent manner. Induced apoptosis may be one of the mechanisms of granulocytopenia induced by hCMV infection.

Human cytomegalovirus aggravates apoptosis of human megakaryocytes via direct infection in vitro / 中国实验血液学杂志

The megakaryocyte and platelet lineage may be one of the major sites of human cytomegalovirus (HCMV) infection. However, whether HCMV aggravates apoptosis in normal megakaryocytes was not well investigated. Megakaryocytic cell line CHRF-288-11 and HCMV AD 169 strain were co-cultured in this study. PCR was used to detect the direct infection of the cells by HCMV IEA expression. The apoptotic cells were analyzed by morphologic observation, DNA ladder formation, annexin V/PI and PI assay with flow cytometry. The results showed that HCMV significantly inhibited the growth of CHRF cells in three different concentrations of viral infection groups (10(-3), 10(-2), 10(-1)). The viability levels in each infection groups were 77%, 73% and 68% respectively after incubation for 7 days, compared with 98% in the control group. Using annexin V/PI with flow cytometry, it was shown that the percentages of apoptotic cells viral infection in groups (10(-3), 10(-2), 10(-1)) were (21.3 +/- 2.49)%, (25.8 +/- 3.65)% and (31.4 +/- 3.91)% at 7 days after infection, while the control was (3.68 +/- 1.47)%. The apoptotic cells were further confirmed by morphologic observation and DNA ladder formation. Furthermore, PCR detection also showed the direct infection by identification of HCMV IEA expression in CHRF cells. This study suggested that HCMV could directly infect megakaryocytes and aggravated apoptosis in HCMV-infected megakaryocytes.

Effect of human cytomegalovirus on hematopoietic system / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the mechanism and the suppression effect of human cytomegalovirus (HCMV) on hematopoietic system.</p><p><b>METHODS</b>Semi-solid culture system was used to observe the effect of HCMV AD169 strain on colony forming unit granulocyte/macrophage (CFU-GM), CFU-erythroid (CFU-E), CFU-multipotent (CFU-Mix) and CFU-megakaryocyte (CFU-MK) growth. The techniques of in situ polymerase chain reaction (IS-PCR) and polymerase chain reaction (PCR) were used to demonstrate the existence of HCMV DNA in the colony cells of cultured CFU-GM, CFU-Mix, CFU-MK and CFU-E, respectively. The immediate early antigen (IEA) mRNA in CFU-MK and late antigen (LA) mRNA in CFU-E were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). HCMV early protein P52 was detected with immunohistochemical technique.</p><p><b>RESULTS</b>HCMV AD169 suppressed the differentiation and proliferation of CFU-GM, CFU-E, CFU-Mix and CFU-MK in vitro significantly (P < 0.05). The suppression was dose-dependent. HCMV DNA was successfully detected in CFU-GM, CFU-Mix, CFU-MK colony cells from viral infection groups by IS-PCR, and was detected in CFU-E by PCR, while it was negative in blank control or mock control groups. CFU-MK colony cells expressed HCMV IEA mRNA with the size of 340 bp in virus infection groups of 10(3) plague forming unit (PFU), 10(4) PFU and 10(5) PFU, respectively. The HCMV LA mRNA was detected by RT-PCR and was 263 bp long in positive control group of HCMV-infected human embryonic fibroblasts. The expression of HCMV LA mRNA in CFU-E was negative. The early protein P52 of HCMV in 10(4) PFU group was also identified by immunohistochemical staining.</p><p><b>CONCLUSION</b>HCMV AD169 strains inhibited the differentiation and proliferation of CFU-GM, CFU-E, CFU-Mix and CFU-MK by the infection of the hematopoietic progenitors. HCMV might cause the suppression of hematopoiesis by direct infection, which is thought to be one of the reasons of HCMV infection associated with thrombocytopenia, neutropenia and anemia.</p>