Due to its unique clinical, immunological and molecular genetic characteristics, biclonal lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changes (POEMS) syndrome is extremely rare in clinical practice, and there is no standard treatment for patients afflicted with this condition. In the present case report, a rare case of double LPL/WM with POEMS syndrome is described. The patient, a 65-year-old male, exhibited significant renal impairment and polylymphadenopathy. The patient was treated with rituximab and his symptoms were resolved following two courses of treatment. A review of the literature was performed, comparing the present case with previous cases. It is hoped that this case report will enable clinicians to gain a better understanding of this disease.

UNASSIGNED: With limited data available from Central Africa, the aim of our study was to evaluate the anti-SARS-CoV-2 Ab prevalence in indigenous residents of Bomassa, a village located in the Sangha region in the Republic of Congo.
UNASSIGNED: Plasma and oropharyngeal swab samples were collected from 304 healthy adult individuals, randomly recruited in May 2021 before vaccine introduction in the area. In addition, 82 plasma samples from the same area in 2019 were included as controls for the investigation of cross-reactivity against other coronaviruses. The SARS-CoV-2 virus was detected by qRT-PCR and sequenced using next-generation sequencing. ELISA was used for detecting IgG, IgM, and neutralizing Ab against SARS-CoV-2 antigens.
UNASSIGNED: Around 4.9% (15/304) of the participants were SARS-CoV-2 positive, with B.1.631 being the only variant identified. Of 109 individuals harboring anti-SARS-CoV-2 IgG and/or IgM Ab, 45.9% (50/109) had anti-SARS-CoV-2 neutralizing Ab. Of the control samples collected before the pandemic, 3.7% (3/82) were positive for IgG, but negative for neutralizing Ab.
UNASSIGNED: Seroprevalence against SARS-CoV-2 occurred in 25% of the indigenous population sample, with almost 50% of these seropositive participants possessing neutralizing antibodies. These findings suggest that the spread of SARS-CoV-2 has been underestimated in the Republic of Congo.

UNASSIGNED: A nationwide cross-sectional epidemiological survey was conducted to capture the true extent of coronavirus disease 2019 (COVID-19) exposure in Senegal.
UNASSIGNED: Multi-stage random cluster sampling of households was performed between October and November 2020, at the end of the first wave of COVID-19 transmission. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies were screened using three distinct ELISA assays. Adjusted prevalence rates for the survey design were calculated for each test separately, and thereafter combined. Crude and adjusted prevalence rates based on test performance were estimated to assess the seroprevalence. As some samples were collected in high malaria endemic areas, the relationship between SARS-CoV-2 seroreactivity and antimalarial humoral immunity was also investigated.
UNASSIGNED: Of the 1463 participants included in this study, 58.8% were female and 41.2% were male; their mean age was 29.2 years (range 0.20-84.8.0 years). The national seroprevalence was estimated at 28.4% (95% confidence interval 26.1-30.8%). There was substantial regional variability. All age groups were impacted, and the prevalence of SARS-CoV-2 was comparable in the symptomatic and asymptomatic groups. An estimated 4 744 392 (95% confidence interval 4 360 164-5 145 327) were potentially infected with SARS-CoV-2 in Senegal, while 16 089 COVID-19 RT-PCR laboratory-confirmed cases were reported by the national surveillance. No correlation was found between SARS-CoV-2 and Plasmodium seroreactivity.
UNASSIGNED: These results provide a better estimate of SARS-CoV-2 dissemination in the Senegalese population. Preventive and control measures need to be reinforced in the country and especially in the south border regions.

Age has been found to be one of the main risk factors for the severity and outcome of COVID-19. However, differences in SARS-CoV-2 specific antibody responses among COVID-19 patients of different age groups remain largely unknown. In this study, we analyzed the IgG/IgM responses to 21 SARS-CoV-2 proteins and 197 peptides that fully cover the spike protein against 731 sera collected from 731 COVID-19 patients aged from 1 to We show that there is no overall difference in SARS-CoV-2 antibody responses in COVID-19 patients in the 4 age groups. By antibody response landscape maps, we find that the IgG response profiles of SARS-CoV-2 proteins are positively correlated with age. The S protein linear epitope map shows that the immunogenicity of the S-protein peptides is related to peptide sequence, disease severity and age of the COVID-19 patients. Furthermore, the enrichment analysis indicates that low S1 IgG responses are enriched in patients aged <50 and high S1 IgG responses are enriched in mild COVID-19 patients aged >60. In addition, high responses of non-structural/accessory proteins are enriched in severe COVID-19 patients aged >70. These results suggest the distinct immune response of IgG/IgM to each SARS-CoV-2 protein in patients of different age, which may facilitate a deeper understanding of the immune responses in COVID-19 patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as a global pandemic. Seroprevalence surveillance is urgently needed to estimate and monitor the growing burden of coronavirus disease 2019 (COVID-19). The aim of this study is to estimate the seroprevalence of SARS-CoV-2 infection among worker population residing in areas under lockdown in Kuwait and investigated their risk factors associated with a positive status. From April 18 to May 10, 2020 a randomly sampled, worker-based survey was conducted in 7 governorate in Kuwait (Ahmadi, Farwaniya, Hawali, Asma, Jahra, and Mubarak Alkabeer) among 10,256 workers. SARS-CoV-2 IgG and IgM antibodies was assessed using a commercially point-of-care lateral flow immunoassay (Biozek medical COVID-19 IgG/IgM Rapid Test Cassette). We estimated an overall seroprevalence (IgG or IgM positive) of 5.9% (95% CI: 5.4-6.3). Notably, SARS-CoV-2 seropositivity was significantly higher in males (6.2%) than females (1.9%) ( p < 0.001). Furthermore, the seroprevalence was significantly different by age group, governorate, and nationality of the workers. These results highlighted that the relatively low prevalence of anti-SARS-CoV-2 antibodies in hotspot areas in a specific population. Thus, we emphasize to repeat the serosurvey in the general population to assess the magnitude of viral spread and monitor the growing burden of COVID-19 in Kuwait.

Background: Currently, a large number of hospitalized coronavirus infectious disease-2019 (COVID-19) patients have met the clinical discharge criteria and have been discharged. Little is known about the sequelae and herd immunity, two important factors influencing the life quality and safety of COVID-19 survivors. Methods: Discharged COVID-19 patients from four medical facilities in Wuhan, China, were followed in order to record and investigate possible post-COVID-19 sequelae and herd immunity. After hospital discharge, patients reported to Fangcang shelter hospitals for an initial 14-day period of mandatory clinical monitoring. After release from these shelter hospitals, patients returned home for self-quarantine. Real-time quantitative PCR (RT-qPCR) was used for severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) detection. Colloidal gold-based immunochromatographic strip assay (ICGSA) was used for anti-SARS-CoV-2 immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody testing. The data for this study are derived from case reports, medical records, and self-reports. Results: A total of 3,677 COVID-19 survivors [median age = 59 years, interquartile range (IQR) = 47-68, range = 10-98; 55.5% female] who were released from four hospitals in Wuhan, China, between January 18 and March 29, 2020 were followed for a median of 144 days (IQR = 135-157). During follow-up, 976 (26.5%) patients had at least one post-COVID-19 sequela. The incidence of post-COVID-19 sequelae among elderly COVID-19 survivors (age ≥60 years) was slightly increased compared to that of young COVID-19 survivors (age <60 years; relative risk = 1.05, 95% CI = 1.02-1.10, p = 0.007). During follow-up, a dramatic reduction of anti-SARS-CoV-2 IgG (88.0%, 95% CI = 84.2-90.4) and IgM (93.2%, 95% CI = 88.5-96.4) antibodies was observed. Among these COVID-19 survivors, 1.2% (n = 45) retested positive for SARS-CoV-2 and 1.0% (n = 37) died during follow-up. Of those who died during follow-up, 70.3% were male and all were negative for both IgG and IgM, except for one person who was IgG-positive. Conclusions: Our study documents significant post-COVID-19 sequelae that impair functions of multiple organ systems in COVID-19 survivors, suggesting that the long-term effects of this disease will negatively impact survivors\' quality of life, continue to strain health care systems, and result in extended periods of lost productivity. Furthermore, female gender and anti-SARS-CoV-2 immunity may play an essential role in the survival after COVID-19 infection.

Toxoplasmosis causes serious complications in immunocompromised and pregnant women. Serological tests for the detection of toxoplasmosis are often designed from parasitic tachyzoites antigens. The process of producing these antigens is very difficult. The purpose of this study was evaluation of T. gondii-rGRA5 for the immunodiagnosis and molecular detection of Toxoplasma infection using enzyme-linked immunosorbent assay (ELISA) and LAMP methods in hemodialysis patients. The GRA5 gene was successfully expressed and purified by affinity chromatography assay and evaluated by western blot. Then it was used to design an ELISA assay. A total of 260 samples were tested for anti-Toxoplasma IgG and IgM antibodies using a commercial ELISA kit and designed ELISA kit. Finally, the LAMP method was used to evaluate the precision and reliability of the results obtained by commercial and designed ELISA kits. The consistency of the results of two methods was analyzed using the Kappa coefficient of agreement. The rGRA5 revealed higher immunoreactivity with 1:100 dilution of sera from toxoplasmosis patients. The specificity and sensitivity of the assay were 93% and 96%, respectively. According to the Kappa coefficient, there was a substantial correlation between the results of ELISA and LAMP based on rGRA5 (≈98%, p < 0.001). Also it showed that rGRA5 protein can be used as an antigenic protein for designing sero-diagnostic tests to identify Toxoplasma infection especially in hemodialysis patients.

OBJECTIVE: This study intended to investigate the dynamics of anti-spike (S) IgG and IgM antibodies in COVID-19 patients.
METHODS: Anti-S IgG/IgM was determined by a semi-quantitative fluorescence immunoassay in the plasma of COVID-19 patients at the manifestation and rehabilitation stages. The immunoreactivity to full-length S proteins, C-terminal domain (CTD), and N-terminal domain (NTD) of S1 fragments were determined by an ELISA assay. Clinical properties at admission and discharge were collected simultaneously.
RESULTS: The positive rates of anti-S IgG/IgM in COVID-19 patients were elevated after rehabilitation compared to the in-patients. Anti-S IgG and IgM were not apparent until day 14 and day ten, respectively, according to Simple Moving Average analysis with five days\' slide window deduction. More than 90% of the rehabilitation patients exhibited IgG and IgM responses targeting CTD-S1 fragments. Decreased total peripheral lymphocytes, CD4+ and CD8+ T cell counts were seen in COVID-19 patients at admission and recovered after the rehabilitation.
CONCLUSIONS: Anti-S IgG and IgM do not appear at the onset with the decrease in T cells, making early serological screening less significant. However, the presence of high IgG and IgM to S1-CTD in the recovered patients highlights humoral responses after SARS-CoV-2 infection, which might be associated with efficient immune protection in COVID-19 patients.

BACKGROUND: Coronavirus disease in 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a global pandemic. Published data suggests that patients with a history of or active malignancy are at increased risk of infection and developing COVID-19 related complications. To date, the published data has analyzed the seroprevalence of COVID-19 infection in the general population, but not in cancer patients. Here we present the results of prevalence of IgG and IgM antibodies against SARS-CoV-2 in cancer patients from the University Hospital of Torrejón (Torrejón de Ardoz, Madrid, Spain).
METHODS: SARS-CoV-2 IgG and IgM antibodies was assessed using a commercially available rapid test (Testsealabs® IgG/IgM Rapid Test Cassette) and collect the result from cancer outpatients who attended the medical oncology consult at University Hospital of Torrejón between June 1st and June 19th, 2020.
RESULTS: We analyzed the serological test results of 229 cancer patients. We estimated an overall seroprevalence (IgG or IgM positive) of 31.4%. The probability of SARS-CoV-2 seropositivity was similar between men and women, type of treatment and cancer stage. The probability of seropositivity was significantly higher in cancer patients with pneumonia compared with cancer patients without pneumonia (Odds Ratio (OR) 7.65 [95% confidence interval (CI) 1,85-31,58]).
CONCLUSIONS: Our results show a higher rate of SARS-CoV-2 antibodies in cancer patients than in the general population. The role of those antibodies in the immune response against the virus infection is unclear.

Polyclonal immunoglobulin therapeutics comprising dosed IgG and IgM combinations are powerful tools in fighting cancer and severe infections. The inability of protein ligands to produce polyclonal IgG- and IgM-enriched formulations and recover monoclonal IgM calls for novel ligands with superior biorecognition activity. In this study, a peptoid ligand discovered by our group, and integrated into affinity adsorbents LigaTrap Technologies\' \"Human IgG\" and \"Human IgM\", were utilized to purify IgG and IgM from complex fluids. IgG purification from human serum using LigaTrap IgG afforded 94.6% purity and 62.9% yield, on par with Protein A/G resins. When challenged with CHO and HEK cell culture harvests with low IgG titer (<1 mg/mL), LigaTrap IgG returned values of yield and purity well above 60% and 90%. LigaTrap IgM was evaluated for purifying IgM in comparison with commercial adsorbents, and afforded a product purity of 93% from a CHO harvest (IgM titer of 1 mg/mL) and 75.1% yield from a HEK harvest (0.5 mg/mL). LigaTrap-M provided IgM enrichment up to 11-fold higher than HiTrap resin. The peptoid adsorbents separated IgG-depleted human serum into IgM- and IgA-enriched fractions. These results demonstrate the potential of the peptoid ligand for manufacturing polyclonal Ig formulations and monoclonal IgM therapeutics.