The aim of this study was to observe the difference in respect to the leukocyte reduction efficiency and quality of fresh-frozen plasma (FFP) from filtered whole blood between two types of in-line filters wherein only filter materials were surface modified by the two methods respectively. Whole blood was kept in refrigerator and filtered within 6 h of collection at ambient temperature. Samples were taken pre- and post filtration for analysis of WBC numbers, coagulation factors and complement activation (n = 8 for each type of filter). All filtered units contained < 2. 5 x 10(6) residual leucocytes. RBCs recovery was over 93%. No significant difference between group A and B was seen. But group B appeared to take longer time for filtration than did group A (9'29" vs. 8'01"). Neither group A nor group B showed statistically significant losses of total protein, album, IgG, IgM, fibrin, factors VIII, IX, vWF and C3 (P > 0.05). Factor V, XI and AT-III decreased significantly in two group filters. Group B showed more significant losses of IgA content and factor V activity than did group A, which appeared to be related to the difference in surface character between group A and group B filters. These two types of filters could remove leukocytes effectively, and no significant changes were observed in the quality of FFP from the filtered whole blood. It is presumed that the filter material with better bio-compatibility will give a high recovery of plasma protein and coagulation factors after filtration.
Blood Coagulation Factors ; metabolism ; Filtration ; instrumentation ; methods ; Humans ; Leukocyte Count ; Leukocyte Reduction Procedures ; instrumentation ; methods

Objective:To investigate the clinical characteristics and short-term follow-up outcomes of primary nephrotic syndrome (PNS) children infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the Omicron variant outbreak in Shanghai, and to provide a reliable reference for clinicians in the diagnosis and treatment.Methods:It was a case-control study. The clinical data of children with PNS (PNS group) who were diagnosed and followed-up up to 1 year in the nephrology department of four children's medical centers in Shanghai, and the children (control group) who had no underlying diseases and were infected with SARS-CoV-2 in Shanghai Jinshan Public Health Center, including the data when they were infected with SARS-CoV-2, were retrospectively analyzed.Results:(1) From March 30th to April 13th, 2022, 6 PNS children in Shanghai were infected with SARS-CoV-2, including 5 boys and 1 girl. The median age was 4.5 (2.0, 11.0) years old. And 30 children were matched by sex, age and disease type as control group, including 20 males and 10 females. The median age was 4.5 (2.0, 9.0) years. There were no significant differences between the PNS group and the control group in clinical symptoms (including fever duration), treatment regimens, vaccine doses and virus clearance time (all P>0.05). (2) The 6 children with PNS included 3 cases of steroid-sensitive type, 3 cases of steroid-resistant type, 2 cases of minimal change disease, 2 cases of focal segmental glomerulosclerosis and 2 cases with no renal biopsy. Before SARS-CoV-2 infection, their primary disease-PNS were stable, and urine protein was negative, four of them were under maintenance treatment with oral steroids or immunosuppressive drugs. At the time of SARS-CoV-2 infection, the symptoms of all of the 6 cases were mild, no severe, critical or fatal cases, and they were all cured and discharged from hospital through medical isolation observation or symptomatic treatment of infections. (3) Five cases of them still had discomfort symptoms such as cough, anorexia, and fatigue after being discharged from the hospital, which lasted for about 1 week. Within 1 year of follow-up, none of the children have suffered from "recurrent positive PCR results" or "secondary infection" of the SARS-CoV-2. (4) Among them, 4 cases of PNS relapsed after SARS-CoV-2 infection, timely addition of steroids was effective, their urine protein quickly turned negative, and there was no recurrence after 1 year of follow-up. (5) Before infection with SARS-CoV-2, the levels of immunoglobulin IgG were lower than the normal reference value in the 4 cases with PNS recurrence. Conclusions:During the Omicron variant outbreak in Shanghai, the infection of SARS-CoV-2 in children with PNS are resulted in high transmission among household contacts. Most of them have mild symptoms and good prognosis. PNS is prone to relapse after SARS-CoV-2 infection, and steroid therapy is effective and safe for these relapse. IgG may be a potential marker for the prognosis of PNS children infected with SARS-CoV-2.