Transient plasma cell dyscrasia in COVID-19 patients linked to IL-6 triggering

Immunological memory in infected & exposure näive individuals one year post SARS-CoV-2 vaccination

Background & objectives COVID-19 has affected millions and wreaked havoc on global healthcare systems as well as a devastating impact on the economies of various nations. Vaccines are highly pivotal in promoting an appropriate immune response. Understanding the effectiveness and stability of the vaccines is essential as these may differ across populations. Hence, this study explored the durability and efficacy of the COVISHIELD (ChAdOx1 nCoV-A) vaccine among healthcare workers (HCWs). Methods In this study, 84 HCWs who received two doses of COVISHIELD and had no breakthrough infections or precautionary doses were assessed. Participants were categorised into four groups (A, B, C, and D) based on pre-immunisation antibody status and SARS-CoV-2 RT-PCR results. Group A had prior infection and IgG antibodies, group B had RT-PCR positivity without detectable antibodies, group C had IgG antibodies without RT-PCR testing, and group D was exposure-näive. Humoral immunity was assessed by measuring IgG antibodies to the spike protein, while cell-mediated immunity was evaluated through SARS-CoV-2-specific T-cell markers and immunophenotyping. Results Over one year, a significant decrease in anti-spike IgG levels was observed in all groups (P<0.0001). It was observed that memory B cells declined significantly among all the groups over a period of one year [group A (P<0.0001), group B (P=0.0080), group C (P=0.0158), and group D (P=0.0004)]; no significant decrease inactivated T-cells was observed over a year. The mean of anti-spike IgG levels in samples from exposed participants (group A, B, C) versus non-exposed (group D) was significantly higher (P<0.0001). Interpretation & conclusions These findings indicate the need for regular booster doses of vaccination due to the waning of immunity by the vaccine. We also demonstrate that hybrid immunity (a combination of immune response post-natural infection and vaccination) provides better protection than vaccination alone.

SARS-CoV-2 infection is not associated with the emergence of monoclonal gammopathies

BACKGROUND

Upon infection activated plasma cells produce large quantities of antibodies which can lead to the emergence of a monoclonal component (MC), detectable by serum protein electrophoresis (SPEP). This study aims to investigate any correlation between SARS-CoV-2 infection and MC development and, if identified, whether it persists during follow-up.

METHODS

SPEPs of 786 patients admitted to hospitals between March 01 2020 and March 31 2022 were evaluated. Positive (SARS-CoV-2+) and negative (SARS-CoV-2-) patients to nasopharyngeal swab for SARS-CoV-2 by RT-PCR were included. The persistence/new occurrence of MC was investigated for all patients during follow-up. Patient groups were compared by chi-square analysis.

RESULTS

MC was identified in 12% of all patients admitted to hospital, of which 28.7% were SARS-CoV-2+. The most common immunoglobulin isotype in both groups was IgG-k. There was no correlation between MC development and SARS-CoV-2 infection (p = 0.173). Furthermore, the risk of MC persistence in SARS-CoV-2-negative patients was revealed to be higher than in the SARS-CoV-2+ at follow-up (HR = 0.591, p = 0.05).

CONCLUSIONS

Our study suggests that the detection of MC during SARS-CoV-2 infection is most likely due to the hyperstimulation of the humoral immune system, as also occurs in other viral infections.

Ovarian Cancer Biomarkers in the COVID-19 Era

Ovarian Cancer (OC) diagnosis is entrusted to CA125 and HE4. Since the latter has been found increased in COVID-19 patients, in this study, we aimed to evaluate the influence of SARS-CoV-2 infection on OC biomarkers. HE4 values above the cut-off were observed in 65% of OC patients and in 48% of SARS-CoV-2-positive patients (not oncologic patients), whereas CA125 values above the cut-off were observed in 71% of OC patients and in 11% of SARS-CoV-2 patients. Hence, by dividing the HE4 levels into quartiles, we can state that altered levels of HE4 in COVID-19 patients were mostly detectable in quartile I (151-300 pmol/L), while altered levels in OC patients were mostly clustered in quartile III (>600, pmol/L). In light of these observations, in order to better discriminate women with ovarian cancer versus those with COVID-19, we established a possible HE4 cut-off of 328 pmol/L by means of a ROC curve. These results demonstrate that the reliability of HE4 as a biomarker in ovarian cancer remains unchanged, despite COVID-19 interference; moreover, it is important for a proper diagnosis that whether the patient has a recent history of SARS-CoV-2 infection is determined.

Humoral immune response to Comirnaty (BNT162b2) SARS-Cov2 mRNA vaccine in Thalassemia Major patients

One of the most urgent needs worldwide is to vaccinate against SARS-CoV-2 as many people as possible. We evaluated humoral response to Comirnaty vaccine in Thalassemia Major patients (TM). We measured SARS-CoV-2-specific antibodies against Spike protein in 57 TM patients and 58 healthy blood donors (HBD). TM and HBD subjects revealed a homogeneous serological response to the Comirnaty (Mean ± SD; TM = 1917,21 ± 1384,49; HBD = 2039,81 ± 1064,44; p = 0,5884). No statistically significant differences were observed among two groups. Interestingly, we observed in 73.3% of asplenic patients Ab-S titres above 800 BAU, whereas only in 26% of non splenectomized patients showed Ab-S titres above 800 BAU). This differences were statistically significant p < 0.039. Further measurement on other Ab types was needed for better understanding humoral response to Comirnaty.

Pattern of serum protein capillary electrophoretogram in SARS- CoV-2 infection

BACKGROUND AND AIMS

Monoclonal/biclonalgammopathy of unknown significance (MGUS/BGUS) is observed in COVID-19. This study was conducted to determine the changes in serum protein electrophoresis (SPEP) in COVID-19.

MATERIALS AND METHODS

In this descriptive (cross-sectional) study, serum inflammatory markers (CRP, IL-6 and ferritin) were measured and SPEP was carried out by capillary electrophoresis method in 35 controls and 30 moderate & 58 severe COVID-19 cases.

RESULTS

Serum inflammatory markers were increased in COVID-19 cases with severity. M-band(s), β-γ bridging and pre-albumin band(s) on SPEP were observed in 15.5, 11 & 12% of severe cases and 3, 4 & 0% moderate COVID-19 cases respectively. Area under curve (AUC) of α 1 and α 2 bands of SPEP increased significantly in severe COVID-19.

CONCLUSIONS

We conclude that SPEP changes like the appearance of M-band(s) indicating MGUS(BGUS), β- γ bridging indicating the presence of fast-moving immunoglobulins, pre-albumin band indicating the rise in serum transthyretin level and the increase in AUC of α 1 and α 2 bands indicating the rise in positive acute phase reactants occur in COVID-19. The occurrence and magnitude of these changes are higher in severe COVID-19 than that in moderate COVID-19. The diagnostic and prognostic significance of these SPEP changes are worth exploring.