Steroid treatment suppresses the CD4+ T-cell response to the third dose of mRNA COVID-19 vaccine in systemic autoimmune rheumatic disease patients

Prolonged steroid treatment has a suppressive effect on the immune system, however, its effect on the cellular response to mRNA vaccine is unknown. Here we assessed the impact of prolonged steroid treatment on the T-cell and humoral response to the SARS-CoV-2 spike (S) peptide following the third dose of the BNT162b2 vaccine in systemic autoimmune rheumatic disease patients. We found that CD4 T-cell response to the S peptide in patients on high-dose long-term steroid treatment showed significantly less S-peptide specific response, compare to low-dose or untreated patients. Remarkably, these results were not reflected in their humoral response, since almost all patients in the cohort had sufficient antibody levels. Moreover, S-peptide activation failed to induce significant mRNA levels of IFNγ and TNFα in patients receiving high-dose steroids. RNA-sequencing datasets analysis implies that steroid treatments' inhibitory effect of nuclear factor kappa-B signaling may interfere with the activation of S-specific CD4 T-cells. This reveals that high-dose steroid treatment inhibits T-cell response to the mRNA vaccine, despite having sufficient antibody levels. Since T-cell immunity is a crucial factor in the immune response to viruses, our findings highlight the need for enhancing the efficiency of vaccines in immune-suppressive patients, by modulation of the T-cell response.

Humoral Response to the Third Dose of Sars-Cov-2 Vaccine in Kidney Transplant Recipients

BACKGROUND

Most solid organ transplant recipients did not develop an appreciable serologic response after 2 doses of the mRNA SARS-CoV-2 vaccine.

METHODS

We analyzed the humoral response after a third dose of the BNT162b2 vaccine in 130 kidney transplant recipients, compared to 48 health care workers, and associated factors, including prevaccine cellular immune response, by evaluating intracellular cytokine production after stimulation of donor's peripheral blood mononuclear cells.

RESULTS

After 2 doses, most of the controls (47 out of 48, 98%) and only 40% of kidney recipients (52 of 130) kidney recipients were seropositive (P < .001). Most seronegative recipients developed a serologic response after the booster (47 out 78, 60%), thus bringing the total number of seropositive recipients to 99 out of 130 (76%). After the third dose, there was a significant increase in antibodies titers in both groups. Decreased humoral response was significantly associated with an older age, lower lymphocyte count, and a lower level of antibodies before booster administration. CD4+TNFα+ and CD4+INFγ+ were correlated with mean increase in antibody titers.

CONCLUSIONS

A third dose of the BNT162b2 mRNA vaccine in kidney recipients is safe and effectively results in increased IgG anti-S levels, including in individuals who were seronegative after 2 doses. Long-term studies of the length of the immune response and protection are required.

The effect of a third-dose BNT162b2 vaccine on anti-SARS-CoV-2 antibody levels in immunosuppressed patients

OBJECTIVES

The recent surge in coronavirus disease 2019 cases led to the consideration of a booster vaccine in previously vaccinated immunosuppressed individuals. However, the immunogenic effect of a third-dose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in immunosuppressed patients is still unknown.

METHODS

This was an observational cohort study of 279 previously vaccinated immunosuppressed patients followed at a single tertiary hospital in Israel. Patients were administered a third dose of the Pfizer-BioNTech mRNA vaccine (BNT162b2) between July 14 and July 21, 2021. Levels of IgG antibodies against the spike receptor-binding domain of SARS-CoV-2 were measured 3 to 4 weeks after vaccination.

RESULTS

Of the cohort of 279 patients, 124 (44.4%) had haematologic malignancies, 57 (20.4%) had rheumatologic diseases, and 98 (35.1%) were solid organ-transplant recipients. Anti-SARS-CoV-2 antibody levels increased in 74.9% of cases. Across the entire cohort, the median absolute antibody levels (expressed in AU/mL) increased from 7 (interquartile range (IQR), 0.1-69) to 243 (IQR, 2-4749) after the booster dose. The response significantly varied across subgroups: The transplant cohort showed the greatest increase in absolute antibody levels (from 52 (IQR, 7.25-184.5) to 1824 (IQR, 161-9686)), followed by the rheumatology (from 22 (IQR, 1-106) to 1291 (IQR, 6-6231)) and haemato-oncology (from 1 (IQR, 0.1-7) to 7.5 (IQR, 0.1-407.5)) cohorts. The χ2 test was 8.30 for difference in fold change (p = 0.016). Of the 193 patients who were seronegative at baseline, 76 became seropositive after vaccination, corresponding to a 39.4% (95% CI, 32.8%-46.4%) seroconversion rate. Transplant patients had the highest seroconversion rate (58.3% (95% CI, 44.3%-71.2%)), followed by rheumatology (44.1% (95% CI, 28.9%-60.5%)) and haemato-oncology (29.7% (95% CI, 22%-38.8%); χ2 = 11.87; p = 0.003) patients.

DISCUSSION

A third dose of BNT162b2 is immunogenic in most immunosuppressed individuals, although antibody response may differ based on the type of disease and immunosuppression. The antibody level that correlates with protection is still unknown; thus, future studies are needed to evaluate clinical outcomes.

Immunogenicity of a third dose of the BNT162b2 mRNA Covid-19 Vaccine in Patients with impaired B cell reconstitution after cellular therapy - a Single Center Prospective Cohort Study

Patients with delayed B-cell reconstitution/B-cell aplasia after cellular therapy show decreased immunogenicity to the BNT162b2 mRNA COVID-19 vaccine. We prospectively evaluated both humoral and cellular immune response to a third vaccine dose in patients after allogeneic HCT (n = 10) or CD19-based chimeric antigen receptor T cells (CAR-T) therapy (n = 6) with low absolute B cell numbers and who failed to mount a humeral response after 2 vaccine doses. Humoral response was documented in 40% and 17% after allogeneic HCT and CAR-T therapy, respectively. None of the patients with complete B-cell aplasia developed anti-vaccine antibodies. Cellular response was documented in all patients after allogeneic HCT and in 83% of the patients after CAR-T. T-cell subclasses levels were not predictive for response, while a longer duration from infusion of cells was associated with a better cellular response. We conclude that cellular response develops with repeated vaccine doses even in patients with B-cell aplasia or delayed B-cell reconstitution, and these patients should therefore be vaccinated. These results should be considered in future studies analyzing immunogenicity in this population. Larger and longer follow-up studies are required to confirm whether cellular immunogenicity translates into vaccine efficacy.

Epidemiology and Transmitted HIV-1 Drug Resistance among Treatment-Naïve Individuals in Israel, 2010-2018

Despite the low prevalence of HIV-1 in Israel, continuous waves of immigration may have impacted the local epidemic. We characterized all people diagnosed with HIV-1 in Israel in 2010–2018. The demographics and clinical data of all individuals (n = 3639) newly diagnosed with HIV-1 were retrieved. Subtypes, transmitted drug-resistance mutations (TDRM), and phylogenetic relations, were determined in >50% of them. In 39.1%, HIV-1 transmission was through heterosexual contact; 34.3% were men who have sex with men (MSM); and 10.4% were people who inject drugs. Many (>65%) were immigrants. Israeli-born individuals were mostly (78.3%) MSM, whereas only 9% of those born in Sub-Saharan Africa (SSA), Eastern Europe and Central Asia (EEU/CA), were MSM. The proportion of individuals from SSA decreased through the years 2010–2018 (21.1% in 2010–2012; 16.8% in 2016–2018) whereas those from EEU/CA increased significantly (21% in 2010–2012; 27.8% in 2016–2018, p < 0.001). TDRM were identified in 12.1%; 3.7, 3.3 and 6.6% had protease inhibitors (PI), nucleotide reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI) TDRM, respectively, with the overall proportion remaining stable in the studied years. None had integrase TDRM. Subtype B was present in 43.9%, subtype A in 25.2% (A6 in 22.8 and A1 in 2.4%) and subtype C in 17.1% of individuals. Most MSM had subtype B. Subtype C carriers formed small clusters (with one unexpected MSM cluster), A1 formed a cluster mainly of locally-born patients with NNRTI mutations, and A6 formed a looser cluster of individuals mainly from EEU. Israelis, <50 years old, carrying A1, had the highest risk for having TDRM. In conclusion, an increase in immigrants from EEU/CA and a decrease in those from SSA characterized the HIV-1 epidemic in 2010–2018. Baseline resistance testing should still be recommended to identify TDRM, and improve surveillance and care.

The association of maternal SARS-CoV-2 vaccination-to-delivery interval and the levels of maternal and cord blood antibodies

OBJECTIVE

To evaluate the correlation of maternal and cord blood levels of SARS-CoV-2 antibodies in pregnant women immunized against COVID-19.

METHODS

A prospective cohort study was performed of pregnant women who delivered at a single university affiliated tertiary medical center. Women who received the COVID-19 vaccine (BNT162b2 Pfizer©) were approached. The correlation between levels of maternal sera and umbilical cord SARS-CoV-2 specific IgG was assessed.

RESULTS

Overall, 58 women were included; of them, 19 had received a single dose and 39 received two doses of the COVID-19 vaccine. Positive levels of umbilical cord IgG were found in 13/19 (68.4%) and 38/39 (97.4%) women after the administration of a single dose and two doses of the vaccine, respectively. The levels of SARS-CoV-2 IgG antibodies in the maternal sera of vaccinated women were positively correlated to their respective concentrations in cord blood sera (ρ = 0.857; R² linear = 0.719; P < 0.001). Thirteen days after vaccination, the ratio of maternal-to-umbilical cord anti Spike IgG antibodies was approximately 1, indicating relatively similar levels in maternal and cord sera.

CONCLUSION

After the SARS-CoV-2 vaccine, levels of maternal and cord blood antibodies were positively correlated, especially when tested after 13 days following administration of the first dose of the vaccine.

Kidney transplant recipients vaccinated before transplantation maintain superior humoral response to SARS-CoV-2 vaccine

Majority of transplant recipients did not develop an appreciable humoral response following SARS-CoV-2 vaccine, in contrast to dialysis patients and healthy individuals. We analyzed the serologic response to BNT162b2 (Pfizer-BioNTech) vaccine in a cohort of 19 kidney transplant recipients, vaccinated prior to transplantation, compare to 109 recipients vaccinated after transplantation, and to 39 healthcare workers, by determining the level of anti-spike antibodies after transplantation. All controls and 17 of 19 (90%) of recipients vaccinated before transplant were seropositive, while only 49 of 109 (45%) recipients vaccinated post-transplant had positive serology (P < .001). Median anti-spike IgG in the group of kidney transplant recipients vaccinated after transplantation (10.7 AU/ml, [IQR 0-62.5]) was lower than the patients vaccinated before transplantation (66.2 AU/ml [21.6-138]), which was significantly lower than in the controls (156 AU/ml [99.7-215.5]). Negative humoral response was associated with vaccination post transplantation (odds ratio 22.4), older age (OR = 1.04), and longer time on dialysis (OR = 1.02), while higher lymphocyte count at time of vaccination was protective (OR = .52). Our findings of sustained superior humoral response to SARS-CoV-2 vaccine in kidney transplant recipients vaccinated prior to transplantation strongly support the recommendations of SARS-CoV-2 vaccination of transplant candidates, especially those younger than 60 years.

Immunogenicity and Safety of the BNT162b2 mRNA COVID-19 Vaccine Among Actively Treated Cancer Patients

Background

Activity and safety of the SARS-CoV-2 BNT162b2 vaccine in actively treated patients with solid tumors is currently unknown.

Methods

We conducted a retrospective study of 326 patients with solid tumors treated with anticancer medications to determine the proportion of cancer patients with immunogenicity against SARS-CoV-2 following 2 doses of the BNT162b2 vaccine. The control group comprised 164 vaccinated healthy adults. Anti-SARS-CoV-2 S immunoglobulin G antibodies were measured using a level greater than 50 AU/mL as a cutoff for seropositivity. Information on adverse effects was collected using a questionnaire. All statistical tests were 2-sided.

Results

Most patients (205, 62.9%) were treated with chemotherapy either alone or with additional therapy; 55 (16.9%) were treated with immune checkpoint inhibitors and 38 (11.7%) with targeted therapy alone; 28 (8.6%) received other combinations. The vaccine was well tolerated, and no severe side effects were reported. Among patients with cancer, 39 (11.9%) were seronegative compared with 5 (3.0%) of the control group (P = .001). Median immunoglobulin G titers were statistically significantly lower among patients with cancer compared with control (931 AU/mL vs 2817 AU/mL, P = .003). Seronegativity proportions were higher in the chemotherapy-treated group (n = 19; 18.8%) compared with the immune checkpoint inhibitor–treated patients (n = 5; 9.1%) and with those treated with targeted therapy (n = 1; 2.6%) (P = .02). Titers were also statistically significantly different among treatment types (P = .002).

Conclusions

The BNT162b2 vaccine is safe and effective in actively treated patients with cancer. The relatively lower antibody titers and lower proportion of seropositive patients, especially among chemotherapy-treated patients, call for continuing the use of personal protective measures in these patients, even following vaccination.

Low immunogenicity to SARS-CoV-2 vaccination among liver transplant recipients

BACKGROUND & AIMS

Two SARS-CoV-2 mRNA vaccines were approved to prevent COVID-19 infection, with reported vaccine efficacy of 95%. Liver transplant (LT) recipients are at risk of lower vaccine immunogenicity and were not included in the registration trials. We assessed vaccine immunogenicity and safety in this special population.

METHODS

LT recipients followed at the Tel-Aviv Sourasky Medical Center and healthy volunteers were tested for SARS-CoV-2 IgG antibodies directed against the Spike-protein (S) and Nucleocapsid-protein (N) 10-20 days after receiving the second Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine dose. Information regarding vaccine side effects and clinical data was collected from patients and medical records.

RESULTS

Eighty LT recipients were enrolled. Mean age was 60 years and 30% were female. Twenty-five healthy volunteer controls were younger (mean age 52.7 years, p = 0.013) and mostly female (68%, p = 0.002). All participants were negative for IgG N-protein serology, indicating immunity did not result from prior COVID-19 infection. All controls were positive for IgG S-protein serology. Immunogenicity among LT recipients was significantly lower with positive serology in only 47.5% (p <0.001). Antibody titer was also significantly lower in this group (mean 95.41 AU/ml vs. 200.5 AU/ml in controls, p <0.001). Predictors for negative response among LT recipients were older age, lower estimated glomerular filtration rate, and treatment with high dose steroids and mycophenolate mofetil. No serious adverse events were reported in either group.

CONCLUSION

LT recipients developed substantially lower immunological response to the Pfizer-BioNTech SARS-CoV-2 mRNA-based vaccine. Factors influencing serological antibody responses include age, renal function and immunosuppressive medications. The findings require re-evaluation of vaccine regimens in this population.

LAY SUMMARY

The Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine elicited substantially inferior immunity in liver transplant recipients. Less than half of the patients developed sufficient levels of antibodies against the virus, and in those who were positive, average antibody levels were 2x less compared to healthy controls. Factors predicting non-response were older age, renal function and immunosuppressive medications.

Reduced humoral response to mRNA SARS-CoV-2 BNT162b2 vaccine in kidney transplant recipients without prior exposure to the virus

COVID-19 is associated with increased morbidity and mortality in transplant recipients. There are no efficacy data available regarding these patients with any of the available SARS-CoV-2 vaccines. We analyzed the humoral response following full vaccination with the BNT162b2 (Pfizer-BioNTech) in 136 kidney transplant recipients, and compared it to 25 controls. In order to exclude prior exposure to the virus, only participants with negative serology to SARS-CoV-2 nucleocapsid protein were included. All controls developed a positive response to spike protein, while only 51 of 136 transplant recipients (37.5%) had positive serology (p < .001). Mean IgG anti-spike level was higher in the controls (31.05 [41.8] vs. 200.5 [65.1] AU/mL, study vs. control, respectively, p < .001). Variables associated with null humoral response were older age (odds ratio 1.66 [95% confidence interval 1.17-2.69]), high-dose corticosteroids in the last 12 months (1.3 [1.09-1.86]), maintenance with triple immunosuppression (1.43 [1.06-2.15]), and regimen that includes mycophenolate (1.47 [1.26-2.27]). There was a similar rate of side effects between controls and recipients, and no correlation was found between the presence of symptoms and seroconversion. Our findings suggest that most kidney transplant recipients remain at high risk for COVID-19 despite vaccination. Further studies regarding possible measures to increase recipient's response to vaccination are required.

POS1206 SEROPREVALENCE OF SARS-CoV-2 ANTIBODIES IN AUTOIMMUNE INFLAMMATORY RHEUMATOLOGIC PATIENTS

Background:

Immune responses in AIIRD patients may be reduced and influenced by immunosuppressive treatments[1].The effect of immunosuppression on the mounting of SARS-CoV-2 antibodies in AIIRD is not clear.

Objectives:

To assess the prevalence of SARS-CoV-2 antibodies in AIIRD patients and to define clinical factors affecting this prevalence.

Methods:

Consecutive consenting AIIRD patients from the Rheumatologic department in Tel Aviv Medical Center participated in the study.

Patients answered a questionnaire and were tested for SARS-CoV-2 antibodies. A two stage antibody testing was done in order to increase specificity.

Results:

The study included 560 AIIRD patients (229 RA, 149 PsA, 84 SLE, 55 vasculitidies, 40 SpA, 3 other CTD), of them 26 patients were found to have SARS-CoV-2 IgG antibodies (4.6%) (Table 1). This was more than double than a previous prevalence in the same clinic population studied after the first wave of the pandemic in Israel, which was 2.07% (accepted for publication).

A lower rate of immunosuppression was found for positive SARS-CoV-2 IgG patients compared to negative serology patients (Table 1, p=0.009). There was also a trend for the subgroup of patients on biologic DMARDS (26.92% vs. 47% respectively, p=0.06).

Positive SARS-CoV-2 PCR test was reported and confirmed in 36 patients, of them 14 (38.89%) had negative serology. Patients who did not have antibodies had numerically more than double rates of glucocorticoids and bDMARDs treatment. The time between positive PCR test to positive serology test was significantly shorter (mean±standart deviation 75.57±40.44 days) than the time between positive PCR to negative serology test (130.79±86.47 (p=0.04) (Table 1 and Figure 1) suggesting a fading of the antibody response with time.

Conclusion:

The prevalence of SARS-CoV-2 IgG was 4.6% in a population of AIIRD patients from a single tertiary medical center in Israel. SARS-CoV-2 seroprevalence tended to be low among AIIRD patients on immunosuppressive treatment, including in patients with a confirmed history of positive SARS-CoV-2 PCR, similar to other studies [3].

As in individuals without AIIRD, the mounting of SARS-CoV-2 IgG seems to fade with time.

Larger studies are needed to confirm the potential effect of immunosuppression on the antibody response in AIIRDs.

Table 1.

Demographic and clinical characteristics of patients with negative and positive SARS-CoV-2 IgG, and in the subgroup with positive SARS-CoV-2 PCR test

Total population (n=560)Positive PCR population (n=36)Negative IgG(n=534)Positive IgG(n=26)PNegative IgG(n=14)Positive IgG(n=22)PFemale n (%)360 (67.42)22 (84.62)0.0810 (71.43)18 (81.82)0.68Age median (95% CI)57 (54.95-57.58)52.5 (46.55-58.6)0.2342 (35.46-53.11)52.5 (47.62-60.65)0.06No. of comorbiditiesmean±STD (95%CI)0.88±1.15 (0.78-0.98)0.92±1.2 (0.44-1.41)0.860.79±1.12 (0.14-1.43)0.96±1.3 (0.4-1.51)0.68AIIRD treatments n(%)Total immunosuppression401 (75.09)13 (50)0.00911 (78.57)12 (54.54)0.175GC113 (21.16)3 (11.54)0.325 (35.71)3 (13.64)0.32csDMARDS257 (48.13)13 (50)17 (50)13 (59.09)0.73bDMARDS251 (47)7 (26.92)0.069 (64.29)7 (31.82)0.09Anti CD-2036 (6.74)00.41 (7.14)00.39

SARS-CoV-2, severe acute respiratory syndrome-coronavirus-2; IgG, immunoglobulin G; PCR, polymerase chain reaction; n, number; 95%CI, 95% confidence interval; GC, glucocorticoids; csDMARDS, conventional synthetic disease modifying antirheumatic drugs; bDMARDS, biologic disease modifying antirheumatic drugs.

References:

[1]V. Furer et al., “Incidence and prevalence of vaccine preventable infections in adult patients with autoimmune inflammatory rheumatic diseases (AIIRD): a systemic literature review informing the 2019 update of the EULAR recommendations for vaccination in adult patients wit,” RMD Open, vol. 5, no. 2, p. e001041, Sep. 2019.

[2]D. Simon et al., “Patients with immune-mediated inflammatory diseases receiving cytokine inhibitors have low prevalence of SARS-CoV-2 seroconversion,” Nat. Commun., vol. 11, no. 1, pp. 1–7, 2020.

Acknowledgements:

This study was performed in collaboration with the Israeli Ministry of Health.

Disclosure of Interests:

None declared.

Immunogenicity of Pfizer-BioNTech COVID-19 vaccine in patients with inborn errors of immunity

Background

In mid-December 2020, Israel started a nationwide mass vaccination campaign against coronavirus disease 2019 (COVID-19). In the first few weeks, medical personnel, elderly citizens, and patients with chronic diseases were prioritized. As such, patients with primary and secondary immunodeficiencies were encouraged to receive the vaccine. Although the efficacy of RNA-based COVID-19 vaccines has been demonstrated in the general population, little is known about their efficacy and safety in patients with inborn errors of immunity (IEI).

Objective

Our aim was to evaluate the humoral and cellular immune response to COVID-19 vaccine in a cohort of patients with IEI.

Methods

A total of 26 adult patients were enrolled, and plasma and peripheral blood mononuclear cells were collected from them 2 weeks following the second dose of Pfizer-BioNTech COVID-19 vaccine. Humoral response was evaluated by testing anti–SARS-CoV-2 spike (S) receptor-binding domain and antinucleocapsid antibody titers and evaluating neutralizing ability by inhibition of receptor-binding domain–angiotensin-converting enzyme 2 binding. Cellular immune response was evaluated by using ELISpot, estimating IL-2 and IFN-γ secretion in response to pooled SARS-CoV-2 S- or M-peptides.

Results

Our cohort included 18 patients with a predominantly antibody deficiency, 2 with combined immunodeficiency, 3 with immune dysregulation, and 3 with other genetically defined diagnoses. Twenty-two of them were receiving immunoglobulin replacement therapy. Of the 26 patients, 18 developed specific antibody response, and 19 showed S-peptide–specific T-cell response. None of the patients reported significant adverse events.

Conclusion

Vaccinating patients with IEI is safe, and most patients were able to develop vaccine-specific antibody response, S-protein–specific cellular response, or both.

Neglect of skin wounds and the risk of becoming a Staphylococcus aureus nasal carrier: a cohort study

Background

Nasal carriers of Staphylococcus aureus have an increased risk of acquiring skin and soft tissue infections, which could manifest as outbreaks, especially in crowded settings. Current prevention programs are ineffective, antibiotic resistance is rising and risk factors for becoming a carrier are incompletely understood. We aimed to examine whether a behavior, the neglect of skin wounds, is a risk factor for becoming a Staphylococcus aureus carrier during training.

Methods

We conducted a field-based cohort study among male infantry trainees in three seasons in Israel during 2011–12. Participants underwent anterior nares cultures and answered structured questionnaires on potential risk factors on two occasions: before and 3 weeks after start of training (N = 542). Attitudes and practices toward neglect of skin wounds were defined as perseverance in training at all costs, despite having a wound. Samples were processed within 18 hours for identification of Staphylococcus aureus. Univariable and multivariable logistic regression analyses were performed to assess risk factors for becoming a carrier.

Results

Carriage prevalence increased by 43.3 % during training, from 33.2 % to 47.6 % (p < 0.01). One-fourth (25.4 %) of those with a negative culture before training became carriers. None of the socio-demographic characteristics was a risk factor for becoming a carrier while the risk was lower in the winter (Odds ratio [OR] = 0.42; 95 % confidence interval [CI]: 0.23-0.78, p < 0.01) and spring (OR = 0.46; 0.26-0.81, p < 0.01) seasons compared to the summer season. Neglect of skin wounds in practice and attitude was a risk factor for becoming a carrier (OR = 2.40; 1.13-5.12, p = 0.02), as well as neglect in practice or attitude (OR = 1.86; 1.04-3.34, p = 0.04) compared to no neglect when controlled for season. The preventable fraction in the population attributed to neglect of skin wounds was 33 %.

Conclusions

Neglect of skin wounds is an independent, common and strong risk factor for becoming a Staphylococcus aureus carrier during training. This preventable behavior should not be ignored and should be addressed in public health programs during training and in other settings. Further research on behavioral determinants of Staphylococcus aureus carriage and infection is warranted.

Molecular analysis of noroviruses involved in acute gastroenteritis outbreaks in military units in Israel, 1999–2004

The study presented here was conducted to determine the genetic properties of noroviruses (NoVs) identified between 1999 and 2004 in army recruits with acute gastroenteritis. Partial sequence analysis of the RNA-dependent RNA polymerase gene revealed the presence of two major sub-genogroups, all of which were related to genogroup II of NoV. Serological analysis using recombinant antigens confirmed this observation. Local strains associated with a 1999 outbreak were closely related to GII-6 strains, while those identified later were very closely related to GII-4 strains. GII-4 strains were also associated with an outbreak in civilian nursing homes in Israel in 2002 and samples from this outbreak were included in this study for comparison. This is the first report describing the molecular properties of NoV strains associated with diarrhea-related morbidity in Israel.

A large-scale gastroenteritis outbreak associated with Norovirus in nursing homes

An increase in gastroenteritis outbreaks due to Norovirus has been reported worldwide. We investigated a large-scale outbreak affecting 246 residents and 33 staff members in six nursing homes in the Tel-Aviv district, Israel, during 3 weeks in 2002. Person-to-person spread was noticed in all nursing homes. The spread of disease could not be attributed to social interactions. Among the elderly residents, the hospitalization rate was 10.2% and the case-fatality rate was 2.0%. Bacteriological cultures were negative. Overall, 7 out of 15 stool specimens were positive for Norovirus by RT-PCR. All were sequenced and found to be 90% identical. The characteristics of this outbreak and the RT-PCR results suggest that illness was caused by Norovirus. Due to the high case-fatality rate of Norovirus gastroenteritis, there should be a high index of suspicion when encountering a gastroenteritis outbreak among the elderly. This will enable prompt action to stop the spread of illness.

An Outbreak of Norovirus Gastroenteritis on an Israeli Military Base

BACKGROUND

Noroviruses (NVs) are a predominant cause of viral gastroenteritis outbreaks, but they are difficult to identify because they cannot be cultivated in cell culture. Therefore, reverse-transcriptase polymerase chain reaction (RT-PCR) assays are widely used in the testing of clinical stool specimens for NV. However, testing of perianal swabs in the context of an outbreak is considered to be an insensitive method for identification of NV using the RT-PCR technique. An outbreak of acute gastroenteritis involving 159 soldiers on a training base of the Israel Defense Force in December 1999 allowed us to evaluate this identification method.

PATIENTS AND METHODS

An epidemiologic investigation, a sanitation survey and a case-control study of exposure to different food items served up to 48 h preceding the outbreak were conducted. Stool samples in the form of post-defecation perianal swabs were collected from 24 ill personnel and three non-ill food handlers. Swabs were tested for the presence of NV by RT-PCR assay.

RESULTS

Epidemiologic data were consistent with a pointsource food-borne outbreak which was associated with consumption of fresh vegetable salad in the base mess hall (OR = 4.38, 95% CI 1.51-13.35). Both epidemiologic and clinical features were suggestive of gastroenteritis caused by NV, and upon laboratory analysis perianal swabs from four of 24 cases were positive for NV.

CONCLUSION

The combination of practical specimen collection with perianal post-defecation swabs, and the utilization of a molecular epidemiology approach, can simplify the rapid identification of outbreaks caused by NVs.

Association study of CAG repeats in the KCNN3 gene in Israeli patients with major psychosis

OBJECTIVES

Several studies reported contradictory findings regarding the association of major psychosis with CAG repeats in the KCNN3 gene. We investigated the contribution of the CAG repeat at the KCNN3 gene, localized to chromosome 1q21.3, to the genetic susceptibility for schizophrenia, schizoaffective and bipolar disorders.

METHODS

Analysis of the number of CAG repeats and the differences in allele length were performed for Israeli Ashkenazi Jews, non-Ashkenazi Jews, and Arabs diagnosed with major psychosis (n=181) versus matched ethnic controls (n=207).

RESULTS

We found no significant difference in the number of CAG repeats between the entire sample of patients and controls. However, an analysis of the differences of allele length revealed a significantly greater number of patients with identical allele length (43.1%) when compared with normal controls (30.4%). Furthermore, an earlier age of non-paranoid schizophrenia onset was found associated with differences in allele sizes. There were no significant differences in the number of CAG repeats and the differences in allele length when subjects were grouped according to gender, ethnic origins of their parents, family history, and diagnostic groups.

CONCLUSIONS

Our results support the hypothesis that a contribution of the KCNN3 gene to genetic susceptibility to major psychosis and their phenotypic polymorphism may be related to the difference of allele length rather than to the number of CAG repeats.

An association of CAG repeats at the KCNN3 locus with symptom dimensions of schizophrenia

BACKGROUND

In 1999 Cardno et al reported that long CAG repeats in the calcium-activated potassium channel gene hSKCa3/KCNN3 are associated with higher negative symptom dimension scores in schizophrenia patients. There has been no attempt to replicate the results. In this study, we investigated whether a symptom polymorphism of schizophrenia is associated with both the CAG repeat numbers and the difference in allele sizes.

METHODS

We tested the association of CAG repeats with symptom models of schizophrenia in 117 unrelated Jewish patients. A multivariate analysis (MANOVA) of two models of schizophrenia with the repeat distribution and the difference in allele sizes was performed.

RESULTS

We found a significant positive association of the number of CAG repeats with negative syndrome, anergia, activation, and paranoid symptoms. In addition, nonparanoid schizophrenia patients who had differences in allele sizes were characterized by earlier onset of illness.

CONCLUSIONS

The study supports the hypothesis that the combined effect of long CAG repeats and the differences in allele sizes contribute to symptom expression of schizophrenia, particularly on the anergia-activation-paranoid axis.

Characterization of Chloroplast Clp proteins in Arabidopsis: Localization, tissue specificity and stress responses

The ATP-dependent Clp protease is one of the newly identified proteolytic systems in plant organelles that incorporate the activity of molecular chaperones to target specific polypeptide substrates and avoid inadvertent degradation of others. We describe new nuclear-encoded ClpC (ClpC1) and ClpP (ClpP3-5) isomers in Arabidopsis thaliana that raise the total number of identified Clp proteins to 19. The extra Clp proteins are localized within the stroma of chloroplasts along with the ClpD, -P1 and -P6 proteins. Potential differential regulation among these Clp proteins was analysed at both the mRNA and protein level. A comparison between different tissues showed increasing amounts of all plastid Clp proteins from roots to stems to leaves suggested the greatest abundance of proteins was in chloroplasts. The increases in protein were mirrored at the mRNA level for most ClpP isomers (ClpP1, -3, -4 and -6) but not for the three Hsp100 proteins (ClpC1, -C2 and -D) and ClpP5, which exhibited little change in transcript levels, suggesting post-transcriptional/translational regulation. Potential stress induction was also tested for all chloroplast Clp proteins by a series of brief and prolonged stress conditions. Short-term moderate and severe stresses (desiccation, high salt, cold, heat, oxidation, wounding and high light) all failed to elicit significant or rapid increases in any chloroplast Clp protein. However, increases in mRNA and protein content for ClpD and several ClpP isomers did occur during long-term high light and cold acclimation of Arabidopsis plants. These results reveal the great complexity of Clp proteins within the stroma of plant chloroplasts, and that these proteins, rather than being rapidly induced stress proteins, are primarily constitutive proteins that may also be involved in plant acclimation to different physiological conditions.

ATP-dependent association between subunits of Clp protease in pea chloroplasts

The chloroplast ATP-dependent Clp protease (EC 3.4.21.92) is composed of the proteolytic subunit ClpP and the regulatory ATPase, ClpC. Although both subunits are found in the stroma, the interaction between the two is dynamic. When immunoprecipitation with antibodies against ClpC was performed on stroma from dark-adapted pea (Pisum sativum L. cv. Alaska) chloroplasts, ClpC but not ClpP was precipitated. However, when stroma was supplemented with ATP, both ClpC and ClpP were precipitated. Co-immunoprecipitation was even more efficient in the presence of ATP-gamma-S, suggesting that the association between regulatory and proteolytic subunits is dependent on binding of ATP to ClpC, but not its hydrolysis. To further test this association, stroma was fractionated by column chromatography, and the presence of Clp subunits in the different fractions was monitored immunologically. When stroma depleted of ATP was fractionated on an ion-exchange column, ClpP and ClpC migrated separately, whereas in the presence of ATP-gamma-S both subunits co-migrated. Similar results were observed in size-exclusion chromatography. To further characterize the precipitated enzyme, its proteolytic activity was assayed by testing its ability to degrade beta-casein. No degradation was observed in the absence of ATP, and degradation was inhibited in the presence of phenylmethylsulfonyl fluoride, consistent with Clp being an ATP-dependent serine protease. The activity of the isolated enzyme was further tested using chimeric OE33 as a model substrate. This protein was also degraded in an ATP-dependent manner, supporting the suggested role of Clp protease as a major housekeeping protease in the stroma.

The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines

Sambucus nigra L. products - Sambucol - are based on a standardized black elderberry extract. They are natural remedies with antiviral properties, especially against different strains of influenza virus. Sambucol was shown to be effective in vitro against 10 strains of influenza virus. In a double-blind, placebo-controlled, randomized study, Sambucol reduced the duration of flu symptoms to 3-4 days. Convalescent phase serum showed a higher antibody level to influenza virus in the Sambucol group, than in the control group. The present study aimed to assess the effect of Sambucol products on the healthy immune system - namely, its effect on cytokine production. The production of inflammatory cytokines was tested using blood - derived monocytes from 12 healthy human donors. Adherent monocytes were separated from PBL and incubated with different Sambucol preparations i.e., Sambucol Elderberry Extract, Sambucol Black Elderberry Syrup, Sambucol Immune System and Sambucol for Kids. Production of inflammatory cytokines (IL-1 beta, TNF-alpha, IL-6, IL-8) was significantly increased, mostly by the Sambucol Black Elderberry Extract (2-45 fold), as compared to LPS, a known monocyte activator (3.6-10.7 fold). The most striking increase was noted in TNF-alpha production (44.9 fold). We conclude from this study that, in addition to its antiviral properties, Sambucol Elderberry Extract and its formulations activate the healthy immune system by increasing inflammatory cytokine production. Sambucol might therefore be beneficial to the immune system activation and in the inflammatory process in healthy individuals or in patients with various diseases. Sambucol could also have an immunoprotective or immunostimulatory effect when administered to cancer or AIDS patients, in conjunction with chemotherapeutic or other treatments. In view of the increasing popularity of botanical supplements, such studies and investigations in vitro, in vivo and in clinical trials need to be developed.

Plant mitochondria contain proteolytic and regulatory subunits of the ATP-dependent Clp protease

The proteolytic machinery of plant organelles is largely unknown, although indications so far point to several proteases of bacterial origin. In this study an Arabidopsis thaliana cDNA was isolated that encodes a homologue of bacterial ClpX, a molecular chaperone and regulatory subunit of the ATP-dependent, serine-type Clp protease. Computer analysis of the predicted plant ClpX revealed a putative mitochondrial transit peptide at the N-terminus, as well as overall sequence similarity to other eukaryotic ClpX homologues. Specific polyclonal antibodies were made to the Arabidopsis ClpX protein and used to confirm its localization in plant mitochondria. In addition to ClpX, a ClpP protein located in mitochondria was also identified from the numerous ClpP isomers in Arabidopsis. Localization of this nuclear-encoded protein, termed ClpP2, was determined first by its close sequence similarity to mitochondrial ClpP human, and later experimentally using ClpP2-specific antibodies with isolated plant organellar fractions. In Arabidopsis, transcripts for both clpX and clpP2 genes were detected in various tissues and under different growth conditions, with no significant variation in mRNA level (i.e. 2-fold) for each gene between samples. Using beta-casein as a substrate, plant mitochondria were found to possess an ATP-stimulated, serine-type proteolytic activity that could be strongly inhibited by antibodies specific for ClpX or ClpP2, suggesting an active ClpXP protease. The recent discovery of homologous mitochondrial ClpX and ClpP proteins in mammals suggests that this type of protease may be common to multicellular eukaryotes.

The effects of early and late administration of M-20 derived interleukin-1 inhibitor on experimental systemic lupus erythematosus

M-20 interleukin-1 inhibitor is produced by a myelomonocytic cell line. The effects of this molecule, mediated via IL-1 inhibition, include decreased proliferative responses of mouse thymocytes, human T-cells and fibroblasts and reduction in parameters of acute inflammation. Previously, we have demonstrated the emergence of a disease resembling systemic lupus erythematosus (SLE) in naive mice immunized with anti-DNA antibodies carrying different pathogenic idiotypes. The disease was manifested by increased titers of various mouse antibodies, concomitant with the appearance of elevated erythrocyte sedimentation rate (ESR), proteinuria and leukopenia. We have applied this model of experimental SLE (immunized with MIV-7, a human monoclonal antibody) to evaluate the influence of M-20 IL-1 inhibitor, administered at different stages (2 weeks before, 1 month and 3 months following immunization) for a period of 2 weeks, on the findings of the disease in mice. It was shown that M-20 IL-1 inhibitor given 2 weeks prior to the immunization resulted in suppression of the disease induction as documented by lower antibody titer level (30%-50% in the immunized mice as compared with controls). Furthermore, reduced autoantibody levels were accompanied by other beneficial findings consisting of lower ESR, less severe proteinuria and elevated leukocyte counts. No beneficial effects of M-20 IL-1 inhibitor were observed when the agent was administered 1 or 3 months following immunization. We conclude that M-20 IL-1 inhibitor has a favorable effect on experimental SLE in mice, provided it is administered before induction of the disease.

Degradation of mistargeted OEE33 in the chloroplast stroma

OEE33, a component of the oxygen-evolving enzyme in chloroplasts, normally resides in the thylakoid lumen. In an attempt to study the fate of mistargeted proteins in chloroplasts, we substituted the bipartite transit peptide of OEE33 with that of CAB7, an integral thylakoid-membrane protein. As a result, when imported into isolated chloroplasts, the chimeric protein protein was targeted to the stroma instead of the thylakoid lumen. Whereas the wild-type OEE33 was totally stable for at least 2 h, the chimeric protein was rapidly degraded, with a half-life of 60 min. Degradation of the chimeric protein was stimulated by ATP supplementation. Degradation could also be observed in lysed chloroplasts, in an ATP-stimulated manner. When lysates were fractionated, the proteolytic activity was found to be associated mainly with the stromal fraction. This activity was very effectively inhibited by all tested inhibitors of serine proteases. Western blot analysis demonstrated that the stromal fraction active in degrading the chimeric OEE33 contains ClpC and ClpP, homologues of the regulatory and proteolytic subunits, respectively, of the bacterial, ATP-dependent, serine-type Clp protease.

In vivo anti-inflammatory effects of the M20 IL-1 inhibitor: II. Effects on serum reactants

We have previously described an IL-1 Inhibitor derived from the M20 myelomoncytic cell line. This line also secretes several molecules of IL-1. We have shown that this factor is specific to IL-1 in vitro, as well as in vivo. In vitro IL-1 induced proliferative responses of mouse thymocytes, human T cells and fibroblasts and IL-1 stimulated PGE2 secretion from fibroblasts, were all inhibited by the M20 IL-1 Inhibitor. In vivo, the IL-1 Inhibitor reduced parameters of acute inflammation such as fever, leukocytosis and local inflammation. This study describes additional effects of the M20 IL-1 Inhibitor on inflammatory serum reactants. Levels of corticosterone and fibrinogen were increased by injection of IL-1, and decreased by the IL-1 Inhibitor. IL-1 reduced zinc and iron plasma levels and elevated copper plasma levels. The M20 IL-1 Inhibitor reversed these changes in a dose dependent manner. Similar effects produced by IL-6 and TNF were unaffected by the M20 IL-1 Inhibitor. Our results indicate that the M20 IL-1 Inhibitor acts specifically on IL-1 induced responses in vivo. Therefore we conclude that this IL-1 Inhibitor has a great potential as an anti-inflammatory agent.

In vivo anti inflammatory effects of the M20 IL-1 inhibitor: I. Effects on acute inflammatory parameters

Previous studies have described an IL-1 Inhibitor produced by a myelomonocytic line developed in our laboratory (Eur J Immunol 1986; 16: 1449). This IL-1 Inhibitor was secreted by the M20 line constitutively in addition to IL-1, from which it could be separated. We have recently shown that the M20 IL-1 Inhibitor is distinct from the IL-1ra. In vitro this factor inhibited IL-1 induced proliferative responses as well as PGE2 secretion by IL-1 induced fibroblasts. We also showed for the first time (Lymphokine Research 1988; 7(3): 268) that an IL-1 inhibitor can reduce IL-1 induced inflammatory effects. This study describes the specific effect of the M20 IL-1 Inhibitor on IL-1 induced parameters of inflammation: fever, leukocytosis and local foot pad swelling or lymph node enlargement. Purified preparations of the IL-1 Inhibitor, when injected together with IL-1, or before the IL-1, reduced fever, leukocytosis, foot pad swelling and lymph node enlargement caused by IL-1. Similar responses were obtained by injection of IL-6 or TNF, but were unaffected by the IL-1 Inhibitor, when injected together. These results indicate that the M20 IL-1 Inhibitor acts specifically on IL-1 induced responses in vivo. The potential importance of this factor as an anti-inflammatory and immune regulatory factor, is supported by the findings of this study.

The M20 IL-1 inhibitor. II. Biological characterization

Interleukin-1 (IL-1) is an important mediator in inflammation and immunological processes. The findings of native IL-1 inhibitors suggest a negative feedback mechanism to down-regulate IL-1 mediated acute inflammation. IL-1 inhibitors were also found elevated in disease states associated with high IL-1 levels. We have previously described one such IL-1 inhibitor derived from the human M20 myelomonocytic cell line. In this paper we present several biological and biochemical characteristics of the M20 IL-1 inhibitor. Various in vitro activities of the inhibitor are described and its IL-1 specificity in these assays is demonstrated. Purification of the inhibitor was performed by DEAE-high performance liquid chromatography, isoelectric focusing, gel filtration and dye ligand chromatography column. This protein factor has a MW of 52 +/- 4 kDa and a pI of 4.15 +/- 0.1. The inhibitor has no cross-reactivity against a panel of known cytokines (IL-1 alpha, IL-1 beta, IL-2, sIL-2R, IL-6, tumor necrosis factor (TNF), interferon-gamma (IFN-gamma)) and is distinct from the IL-1 receptor antagonist (IL-1ra). The purified IL-1 inhibitor was destroyed by trypsin, 2-mercaptoethanol, sodium dodecyl sulfate and extremes in pH and in temperature. Only IL-1 induced (but not the IL-2, IL-6 or TNF induced) thymocyte proliferation and PGE2 production by fibroblasts were inhibited by the inhibitor, thus showing specificity to IL-1 in these assays.

The M20 IL-1 inhibitor. I. Purification by preparative isoelectric focusing in free solution

An interleukin-1 (IL-1) inhibitor produced by the M20 myelomonocytic cell line has been shown to be active in various in vitro and in vivo IL-1 induced parameters. This inhibitor has been purified from the conditioned medium by gel filtration through a Sephacryl S-300 column or dye ligand chromatography on Affi-Gel blue column, followed by isoelectric focusing in free solution in the pH range 3-5 using the Rotofor cell. When gel filtration by FPLC with the Superose 12 column was used as the final step, the combined sequence of purification procedures resulted in a 1600-fold purification of the IL-1 inhibitor. The purified IL-1 inhibitor has a molecular weight of approximately 52 +/- 4 kDa and a pI of 4.15 +/- 0.1. By SDS-PAGE analysis the inhibitor preparation thus obtained showed the presence of two protein bands, while a few closely spaced protein bands were seen by analytical isoelectric focusing in polyacrylamide gels (pH 3-6). Some of these bands in PAGIF might correspond to different degrees of glycosylation of the inhibitory protein. Although the M20 IL-1 inhibitor has not yet been purified to homogeneity, it should be stressed that the procedures used, allowed us to remove the great majority of the proteins present in the medium in which the M20 cells were cultured, and to recover in satisfactory yield the inhibitor which we consider likely to be present in the conditioned medium in subnanomolar concentrations.

The specific IL-1 inhibitor from the human M20 cell line is distinct from the IL-1 receptor antagonist

Several inhibitors of IL-1 have been described. Four appear to be the same: one purified from urine of patients with monocytic leukemia, another from IgG-stimulated monocytes, a third from PMA-induced U937 cels, and a fourth from keratinocytes. Because these IL-1 inhibitors compete with bona fide IL-1 for occupancy of IL-1 receptors, they are now called the IL-1 receptor antagonist (IL-1ra) or IL-1 receptor antagonist protein (IRAP). We have described another IL-1-specific inhibitor produced by the human myelomonocytic leukemia cell line, M20. This inhibitor specifically blocks IL-1-induced effects both in vitro and in vivo. In the present study, we compared the M20 IL-1 inhibitor with IL-1ra using neutralization in an IL-1 bioassay and immunoblotting with an anti-IL-1ra antibody that recognizes natural IL-1ra. Neutralization experiments, immunoblotting, and western blotting obtained after transfer from SDS-PAGE revealed that anti-IL-1ra does not recognize the M20 IL-1 inhibitor. In addition, the isoelectric point and molecular weight of the M20 IL-1 inhibitor were different from those of the IL-1ra. From these data, we conclude that the M20 IL-1 inhibitor is antigenically unrelated to the IL-1ra but is a distinct and specific IL-1 inhibitor.