[A comparison of clinical characteristics between patients with and without"recurrence"RNA positive with COVID-19].

Objective: To analysis the clinical characteristics of"recurrence"RNA positive patients with Coronavirus disease 2019 （COVID-19） and compared with those without"recurrence". Methods: 98 patients with COVID-19 in Wuhan Jinyintan Hospital and designated treatment hospitals in Quanzhou were included in this study from February 2020 to April 2020. There were 55 males and 43 females， aged from15 to 83 years， with a median age of 57.5 years， in which 20 cases were complicated with basic diseases. 15 of these patients had been diagnosed and hospitalized had been found as"recurrence"2019-nCoV RNA positive after discharge while the other 83 cases were all negative. The clinical classification of all patients was common type. Clinical data of the COVID-19 RNA"recurrence"patients were collected， and general situations， symptoms， laboratory examinations and CT images were also observed and analyzed. The patients were divided into 2019-nCoV"recurrent"group and 2019-nCoV"non-recurrent"group. There are 10 males and 5 females in 2019-nCoV"recurrent"group while 45 males and 38 females in"non-recurrent"group （χ²=0.800，P=0.371）. The age of 2019-nCoV"recurrent"group （57±21） was higher than that of"non-recurrent"group（53±17）. 8 of 15 the COVID-19"recurrent"group patients and 12 of 83"non-recurrent"patients have basic diseases. IgG and IgM of 2019-nCoV， IL-6， procalcitonin， ESR， CRP， BNP and other serum biochemical index levels were measured and compared between groups. Results: （1） The proportion of patients with common type of COVID-19 was 15.3% during 2-week medical observation after discharge. （2） All of the 2019-nCoV"recurrent"patients were hospitalized due to COVID-19 RNA positive， when they were quarantined after discharged from hospital. All the patients with mild symptoms which were clarified as common type， including 5 cases of fever， 6 cases of cough， 5 cases of expectoration， and 2 cases of slight shortness of breath. The time of symptoms appeared on （5.73±2.82） days after discharge. （3） The serum procalcitonin of all 2019-nCoV"recurrent"group patients were normal（all<0.05 ng/ml）. The BNP of"recurrent"group （151±171） ng/L， was higher than that of"non-recurrent"group （63±78） ng/L （t = 3.207， P = 0.000）. There was no significant difference in laboratory tests like leukocyte ［（6.17±2.4） and （6.04±2.41）×109/L］， lymphocyte［（1.59±0.52） and （1.32±0.64）×109/L］， CRP ［（12.54±28.20） and （21.74±25.63）mg/L］， ESR ［（31.07±28.72） and （34.10±22.16）mm/1 h］， AST ［（24.73±9.15） and （30.24±23.20）U/L］， ALT ［（22.60±12.82） and （36.47±34.12）U/L）， LDH ［（268±208） and （270±164）U/L］， D-dimer ［（0.60±0.50） and （0.84±0.98）µg/L］， ferritin ［（294±195） and （395±319）µg/L］， IL-6 ［（9.17±6.42） and （14.28±17.74）ng/Lï¼½ and BUN （5.77±2.66） and （4.74±2.81）U/Lï¼½ between"recurrent"and"non-recurrent"groups （all P>0.05）. （4） In"recurrent"group， ground glass， exudative or solid lesions could be found in most of the chest CT performed on re-admission. Meanwhile， fibrosis lesion was relatively rare. （5） There were no secondary transmissions were found to be caused by the 2019-nCoV"recurrent"group patients. Conclusions: Most of the 2019-nCoV patients had underlying diseases and active lesions were still found in CT images， so the possibility of virus replication may still exist. All"recurrent"patients had mild illness which may suggest that they were in recovery stage, and no evidence of transmission is found.

CpG Oligodeoxynucleotide1826 combined with radioresistant cancer cell vaccine confers significant antitumor effects.

Immunotherapy is a hot issue in cancer research over the years and tumor cell vaccine is one of the increasing number of studies. Although the whole tumor cell vaccine can provide the best source of immunizing antigens, there is still a limitation that most tumors are not naturally immunogenic. CpG Oligodeoxynucleotides (CpG ODNs), synthetic oligonucleotides containing a cytosine-phosphate-guanine(CpG) motif, was shown to enhance immune responses to a wide variety of antigens. In this study, we generated the radioresistant Lewis lung cancer cell by repeated X-ray radiation and inactivated it as a whole tumor cell vaccine to enhance the immunogenicity of tumor cell vaccine. Mice were subcutaneously immunized with this inactivated vaccine combined with CpG ODN1826 and then inoculated with autologous Lewis lung cancer (LLC) to estimate the antitumor efficacy. The results showed that the radioresistant tumor cell vaccine combined with CpG ODN1826 could significantly inhibit tumor growth, increased survival of the mice and with 20% of the mice surviving tumor free in vivo compared with the unimmunized mice bearing LLC tumor. A significant increase of apoptosis was also observed in the tumor prophylactically immunized with vaccine of inactivated radioresistant tumor cell plus CpG ODN1826. The potent antitumor effect correlated with higher secretion levels of tumor necrosis factor-alpha(TNF-α) and lower levels of interleukin-10(IL-10) concentration in serum. Furthermore, the results suggested that the antitumor mechanism was probably depended on the decreased level of programmed death ligand-1(PD-L1) which plays an important role in the negative regulation of immune response by the inhibition of tumor antigen-specific T cell activation. These findings clearly demonstrated that the radioresistant tumor cell vaccine combined with CpG ODN1826 as an appropriate adjuvant could induce effective antitumor immunity in vivo.