The Concordance between Mumps and Rubella Sero-Positivity among the Israeli Population in 2015.

Mumps and rubella are vaccine-preventable viral diseases through the measles-mumps-rubella-varicella (MMRV) vaccine, administered at 12 months and again at 6 years. We assessed the sero-prevalence of mumps and rubella, identified factors associated with sero-negativity, and evaluated concordance between mumps and rubella sero-positivity. A national cross-sectional sero-survey was conducted on samples collected in 2015 by the Israel National Sera Bank. Samples were tested for mumps and rubella IgG antibodies using an enzyme-linked immunosorbent assay. Of 3131 samples tested for mumps IgG, 84.8% (95%CI: 83.5-86.0%) were sero-positive. Sero-negativity for mumps was significantly associated with age (high odds ratios observed in infants younger than 4 years and 20-29 years old subjects). Of 3169 samples tested for rubella IgG antibodies, 95.2% (95%CI: 94.4-95.9%) were sero-positive. Rubella sero-negativity was significantly associated with age (high odds ratios observed in children younger than 4 years old and adults older than 30 years), males, Jews, and others. Concordant sero-positivity for both mumps and rubella viruses was observed in 83.9% of the tested samples. The Israeli population was sufficiently protected against rubella but not against mumps. Since both components are administered in the MMRV vaccine simultaneously, the mumps component has a lower uptake than rubella and quicker waning.

Seropositivity of measles antibodies in the Israeli population prior to the nationwide 2018 - 2019 outbreak.

Measles vaccine is administered in Israel as part of the routine childhood immunization program, at ages 1 and 6 years. In this study, we assessed seropositivity of the Israeli population against measles before the onset and propagation of the 2018-2019 measles outbreak. From the Israel Center for Disease Control National Serum Bank, 3,164 samples collected during 2015 were tested for measles antibodies. All the tests were performed using Enzyme-Linked Immunosorbent Assay (ELISA) commercial kit (Enzygnost, Anti-Measles Virus/IgG: Behring, Marburg, Germany). The overall seropositivity rate for measles was 90.7%. The seropositivity rate at 6 months and younger was 48.9%, and decreased to 3.8% among infants aged 6-11 months. Seropositivity increased to 90.7% in the 1-4-year age group, and reached 96.1% for 5-9 year-old children. Our results suggest high immunity in the Israeli population against measles virus, but not high enough to prevent outbreaks because of pockets of specific population groups with low immunization coverage. Infants between ages 6 and 11 months and children younger than 2 years had the lowest seropositivity rates being the age groups with the highest attack rates of measles during the epidemic of 2018. Efforts should be aimed at avoiding any delay in vaccination once a child reaches the age of 1 year and improving immunity levels in children aged 1-4 years.

A new risk model to predict time to first treatment in chronic lymphocytic leukemia based on heavy chain immunoparesis and summated free light chain.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is frequently accompanied by immune dysregulation. AIMS: In this multicenter prospective study, we investigated whether heavy + light chains (HLC: IgGκ, IgGλ, IgAκ, IgAκ, IgMκ, IgMλ) and IgG subclasses (IgG1, IgG2, IgG3, and IgG4) could be used as novel prognostic markers of immunoparesis in 105 treatment-naïve patients with CLL. RESULTS: Heavy + light chains immunoparesis of ≥1, ≥2, and ≥3 isotypes was evident in 74 (70%), 58 (55%), and 36 (34%) patients, respectively. Severe HLC immunoparesis was identified in 40 (38%) patients. Of the IgG subclasses, IgG1 and IgG2 were most frequently suppressed, affecting 46 (44%) and 36 (34%) patients, respectively; 63 (60%) patients had low levels of at least one IgG subclass. In multivariate analysis, severe HLC immunoparesis (hazard ratio [HR]: 36.5; P = .010) and ΣFLC ≥ 70 mg/L (HR: 13.2; P = .004) were the only factors independently associated with time to first treatment (TTFT). A risk model including these variables identified patients with 0, 1, and 2 risk factors and significantly different TTFT (P < .001). Patients with two factors represented an ultra-high-risk group with a median TTFT of only 1.3 months. CONCLUSION: The above findings demonstrate the potential for the use of HLC immunoparesis, together with sFLC measurements, as future prognostic biomarkers in CLL.

Performance of Three Common Hepatitis C Virus (HCV) Genotyping Assays for Identification of HCV Genotype 2/1 Chimeras.

Besides seven major hepatitis C virus (HCV) genotypes (GT), a number of intergenotypic recombinant strains have been described. These so-called chimeras combine genetic characteristics of different HCV genotypes. However, correct genotype classification is important, as choice and duration of direct-acting antiviral (DAA) treatment is mainly based on the viral genotype. Therefore, misclassification of chimeras might lead to suboptimal treatment of patients infected with these strains. For example, 2k/1b chimeras are typically described as HCV genotype 2 strains by commercially available hybridization assays, but real-time PCR-based tests recognizing another HCV region might be more suitable for correct chimera detection. In this study, the analytic capacity of the hybridization-assay Versant HCV Genotype 2.0 (LiPA 2.0) and the real-time PCR-based-assays cobas HCV GT and Abbott RealTime HCV Genotype II were tested in a selected cohort of 230 patients infected with HCV genotype 1 (n = 53) and 2 (n = 177) and 48 patients infected with HCV 2/1 chimeric strains. While the Versant HCV Genotype 2.0 (LiPA 2.0) assay failed to identify chimeras in all of the patients (48/48, 100%), cobas HCV GT and Abbott HCV Genotype II assays identified chimeras correctly in 90% (43/48) and 65% (31/48) of the cases, respectively. In conclusion, while the hybridization-based Versant HCV Genotype 2.0 (LiPA 2.0) assay seems to be unsuitable for detection of HCV 2/1 chimeras, use of the real-time PCR-based assays cobas HCV GT and Abbott RealTime HCV Genotype II led to a higher rate of chimera detection.

The seroprevalence of West Nile Virus in Israel: A nationwide cross sectional study.

West Nile Virus (WNV) is endemic in Israel, affecting yearly 40-160 individuals. Israel is located on a central migratory path between Africa and Eurasia and most West Nile Fever (WNF) cases reported in recent years were among residents of the coastal plain. The aim of the study was to evaluate the seroprevalence of WNV among the Israeli population and to assess correlates for WNV infection. A cross-sectional nationwide serologic survey was conducted using 3,145 serum samples collected by the national Israeli serum bank during 2011-2014, representing all age and population groups in Israel. Prevalence rates of WNV IgG antibodies were determined. Logistic regressions models were applied to assess the associations between demographic characteristics and WNV seropositivity. 350 samples were positive to WNV (11.1%; 95%CI: 10.0-12.3%). In the multivariable analysis, there was a significant association between seropositivity and the Arab population group vs. Jews and others (OR = 1.86, 95%CI: 1.37-2.52), the time lived in Israel [50-59 years vs. 0-9 years; OR = 10.80 (95%CI: 1.03-113.46) and ≥60 years vs. 0-9 years; OR = 14.00 (1.32-148.31)] residence area] Coastal Plain, Inland Plain (Shfela) and Great Rift Valley vs. Upper Galilee; OR = 2.24 (95%CI: 1.37-3.65), OR = 2.18 (95%CI: 1.18-4.03), OR = 1.90 (95%CI: 1.10-3.30), respectively [and rural vs. urban settlement (OR = 1.65, 95%CI: 1.26-2.16). People, who reside in the Coastal Plain, Inland Plain and Great Rift Valley, should be aware of the risk of contracting WNV and reduce exposure to mosquito bites, using insect repellents, and wearing protective clothing. The Ministry of Environmental Protection should be active in reducing the mosquito population by eliminating sources of standing water, a breeding ground for mosquitoes.

Origin, prevalence and response to therapy of hepatitis C virus genotype 2k/1b chimeras.

BACKGROUND & AIMS: Little is known about the epidemiology and frequency of recombinant HCV genotype 2/1 strains, which may represent a challenge for direct antiviral therapy (DAA). This study aims to identify the epidemiology and phylogeny of HCV genotype 2/1 strains and encourages genotype screening, to select the DAA-regimen that achieves the optimal sustained virologic response. METHODS: Consecutive samples from HCV genotype 2 infected patients, according to commercial genotyping, from Germany, Italy and Israel were re-genotyped by Sanger-based sequencing. Virologic, epidemiological, and phylogenetic analyses including other published chimeras were performed. RESULTS: Sequence analysis of 442 supposed HCV genotype 2 isolates revealed 61 (genotype 2k/1b (n=59), 2a/1b (n=1) or 2b/1a (n=1)) chimeras. No chimeras were observed in Italy, but the frequency was 14% and 25% in Germany and Israel. Treatment of viral chimera with sofosbuvir/ribavirin led to virologic relapse in 25/27 patients (93%). Nearly all patients treated with genotype 1-based DAA-regimens initially (n=8/9), or after relapse (n=13/13), achieved a sustained virologic response. Most patients with 2k/1b chimeras (88%) were originally from eight different areas of the former Soviet Union. All known 2k/1b chimeras harbour the same recombination breakpoint and build one phylogenetic cluster, while all other chimeras have different phylogenies. CONCLUSIONS: The HCV genotype 2k/1b variant derives from one single recombination event most likely in the former Soviet Union, while other chimeras are unique and develop independently. A relatively high frequency has been observed along the migration flows, in Germany and Israel. In countries with little migration from the former Soviet Union the prevalence of 2k/1b chimeras is expected to be low. Treatment with sofosbuvir plus ribavirin is insufficient, but genotype 1-based regimens seem to be effective. Lay summary: The frequency of recombinant HCV is higher than expected. A novel recombinant variant (HCV genotype 2a/1b) was identified. Screening for recombinant viruses would contribute to increased response rates to direct antiviral therapy.

Evaluation of the NanoCHIP® Gastrointestinal Panel (GIP) Test for Simultaneous Detection of Parasitic and Bacterial Enteric Pathogens in Fecal Specimens.

Infectious gastroenteritis is a global health problem associated with high morbidity and mortality rates. Rapid and accurate diagnosis is crucial to allow appropriate and timely treatment. Current laboratory stool testing has a long turnaround time (TAT) and demands highly qualified personnel and multiple techniques. The need for high throughput and the number of possible enteric pathogens compels the implementation of a molecular approach which uses multiplex technology, without compromising performance requirements. In this work we evaluated the feasibility of the NanoCHIP® Gastrointestinal Panel (GIP) (Savyon Diagnostics, Ashdod, IL), a molecular microarray-based screening test, to be used in the routine workflow of our laboratory, a big outpatient microbiology laboratory. The NanoCHIP® GIP test provides simultaneous detection of nine major enteric bacteria and parasites: Campylobacter spp., Salmonella spp., Shigella spp., Giardia sp., Cryptosporidium spp., Entamoeba histolytica, Entamoeba dispar, Dientamoeba fragilis, and Blastocystis spp. The required high-throughput was obtained by the NanoCHIP® detection system together with the MagNA Pure 96 DNA purification system (Roche Diagnostics Ltd., Switzerland). This combined system has demonstrated a higher sensitivity and detection yield compared to the conventional methods in both, retrospective and prospective samples. The identification of multiple parasites and bacteria in a single test also enabled increased efficiency of detecting mixed infections, as well as reduced hands-on time and work load. In conclusion, the combination of these two automated systems is a proper response to the laboratory needs in terms of improving laboratory workflow, turn-around-time, minimizing human errors and can be efficiently integrated in the routine work of the laboratory.

Association of Vitamin B12 Deficiency with Homozygosity of the TT MTHFR C677T Genotype, Hyperhomocysteinemia, and Endothelial Cell Dysfunction.

BACKGROUND: Hyperhomocysteinemia is associated with increased cardiovascular risk, but treatment with folic acid has no effect on outcome in unselected patient populations. OBJECTIVES: To confirm previous observations on the association of homozygosity for the TT MTHFR genotype with B12 deficiency and endothelial dysfunction, and to investigate whether patients with B12 deficiency should be tested for 677MTHFR genotype. METHODS: We enrolled 100 individuals with B12 deficiency, tested them for the MTHFR C677T polymorphism and measured their homocysteine levels. Forearm endothelial function was checked in 23 B12-deficient individuals (13 with TT MTHFR genotype and 10 with CT or CC genotypes). Flow-mediated dilatation (FMD) was tested after short-term treatment with B12 and folic acid in 12 TT MTHFR homozygotes. RESULTS: Frequency of the TT MTHFR genotype was 28/100 (28%), compared with 47/313 (15%) in a previously published cohort of individuals with normal B12 levels (P = 0.005). Mean homocysteine level was 21.2 ± 16 µM among TT homozygotes as compared to 12.3 ± 5.6 µM in individuals with the CC or CT genotype (P = 0.008). FMD was abnormal ( 6%) in 9/13 TT individuals with B12 deficiency (69%), and was still abnormal in 7/12 of those tested 6 weeks after B12 and folic treatment (58%). CONCLUSIONS: Among individuals with B12 deficiency, the frequency of the TT MTHFR genotype was particularly high. The TT polymorphism was associated with endothelial dysfunction even after 6 weeks of treatment with B12 and folic acid. Based on our findings we suggest that B12 deficiency be tested for MTHFR polymorphism in order to identify potential vascular abnormalities and increased cardiovascular risk.

Triple positive antiphospholipid antibody profile in outpatients with tests for lupus anticoagulants.

BACKGROUND: A triple positive antiphospholipid (aPL) antibody profile [two positive serum IgG aPL antibodies along with one positive functional plasma lupus anticoagulant (LAC) test result] is associated with an increased risk for thrombosis, whereas patients with single positive test results may have little to no increased risk. The frequency of triple positivity in outpatients with various combinations of LAC test results is unclear. METHODS: We extracted from our database all LAC test results [dilute Russell viper venom times (dRVVT) and silica clotting times (SCT)] that had concomitant serum IgG aPL testing [both serum anti ß2-glycoprotein I (anti-ß2GPI) and anti-cardiolipin (aCL) antibodies]. RESULTS: There were 3195 patients without a prolonged prothrombin time. Double antibody positivity was found in 1% (31/2955) of those with normal functional LAC test results, in 16.0% (31/81) of those with a positive dRVVT, in 12.7% (10/79) of those with a positive SCT, and in 56.3% (45/80) of those with both tests positive (p<0.001). A triple positive aPL antibody profile was found in 28.3% (68/240) of those with at least one positive LAC test result. CONCLUSIONS: We conclude that 28% of patients with elevated LAC tests have a triple positive aPL antibody profile and patients with two positive LAC tests have a higher prevalence of a triple positive profile than do those with one positive LAC test result.

Auto-validation of complete blood counts in an outpatient's regional laboratory.

BACKGROUND: The rate of auto-validation is dependent on the ability of the laboratory information system (LIS) to integrate historical data, on the frequency and methods for identifying analyzer errors, and on the criteria for reflex testing, including the need for peripheral smear review. The rate of auto-validation in outpatient laboratories, however, is unclear. METHODS: We examined 45,925 consecutive complete blood count (CBC) test results (1 January, 2014-31 January, 2014) from patients aged 50±24 years. The LIS auto-validates all samples according to set criteria. Technicians validated test results when previous CBC test results were required to determine: 1) the need for peripheral slide review and/or sample rerun or 2) the need for reflex testing to detect autoimmune hemolytic anemia or ß-thalassemia minor. RESULTS: The auto-validation rates were 97.6% after rejecting results requiring validation to determine the need for a peripheral smear review and/or sample rerun. This decreased to 92.9% after including reflex testing to determine the reasons for normocytic and microcytic anemia. We estimated that auto-validation decreased the workload by 7.7-11.6 h per 3000 test results. CONCLUSIONS: We conclude that very high auto-validation rates are possible in outpatient general laboratories, leading to conformity in the validation process and a considerable estimated savings in technician time. Further studies are needed in other settings.

Anemia and estimated glomerular filtration rates.

OBJECTIVE: To determine the relationship between the estimated glomerular filtration rate (eGFR) and the prevalence of anemia that has potential implications for reporting results of the eGFR. METHODS: Serum creatinine and hemoglobin test results from 18,474 outpatients aged 50 years or older were reviewed. We calculated the eGFR using the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) and the Modification of Diet in Renal Disease equation (MDRD) and determined the odds of anemia (according to the World Health Organization definition) at various eGFR levels, adjusted for age and gender. RESULTS: The lowest proportion of anemia was observed in those with an eGFR of 80-89 mL/min per 1.73 m(2) and 90-99 mL/min per 1.73 m(2) (MDRD and CKD-EPI respectively), with an increasing prevalence of anemia in those with either an eGFR of 60-69 mL/min per 1.73 m(2) or 100-109 mL/min per 1.73 m(2) calculated by either equation (p<0.05) with a dose-response effect. CONCLUSIONS: We found a U-shaped relationship between anemia and the eGFR, suggesting that values >60 mL per 1.73 m(2) should be reported. However, the clinical utility and potential side effects of reporting such values need to be determined. Also, these preliminary findings require confirmation by studies in other settings.

Criteria for reflex peripheral smear review in infants.

Criteria for peripheral smear review are designed to include those samples with results outside the reference interval and can be more extreme based on what is considered to have clinical utility. However, we are unaware of previous studies that reported the distributions of various complete blood cell count (CBC) parameters in infants. In the following study we reviewed screening CBC results of 692 infants aged 9-15 months in order to determine the proportion of peripheral smear reviews recommended according to consensus criteria and that after adjusting for the observed distributions of the various parameters. According to consensus criteria the recommended reflex peripheral smear review rate was 39.7% (95% CI 36.1-43.4) whereas after adjustment for the observed distributions, the rate fell to 5.6% (95% CI 3.9-7.3) (p < 0.001). The major reasons for the difference in rates were the high proportion of infants with an absolute lymphocyte count > 7 × 10(9)/L (17.5%), the presence of a plus one blast flag (4.3%), and a large unstained cell count of ≥ 5% (26.2%) (equivalent to + 1 atypical flag). We found that international consensus criteria for reflex peripheral smear review results in a very high peripheral smear review rate in well infants, and might be inappropriate.

The association of serum antiphospholipid antibodies and dilute Russell's viper venom times.

AIMS: We hypothesised that there is a threshold value for the association of dilute Russell's viper venom times (dRVVT) with positive immunoglobin G antiphospholipid antibody (IgG-APLA) test results. METHODS: We tested 120 controls and a cohort of 2412 outpatients who had concomitant test results for dRVVT and IgG-APLA (IgG antibodies to cardiolipins and ß2-glycoprotein I). We also selected a subgroup who had repeated IgG-APLA tests at least 12 weeks apart (1398 patients with multiple ß2-glycoprotein I tests and 672 with multiple aCL tests). We cross tabulated the proportion of IgG-APLA single positive, double positive and persistently positive antibodies with dRVVT values. RESULTS: The distribution of the dRVVT results from the reference population was consistent with an upper limit of the reference interval of 1.22 to >1.48. A consistent increase in the proportion of IgG-APLA single, double positive and persistently positive antibody tests occurred in the group with a normalised dRVVT ratio of 1.40-1.49. IgG-APLA double positivity was found in 12.5% (4 of 32) patients with a ratio of dRVVT 1.40-1.49 compared with 3.3% (6/181) of those with a ratio of dRVVT 1.20-1.39 (p=0.045). CONCLUSIONS: We conclude that there is an association between dRVVT positivity and elevated proportions of single, double and persistently positive IgG-APLA test results with an apparent threshold effect. These findings may provide a general guide to risk and suggest a way to choose from a wide range of possible upper limits of the reference interval.

Automated evaluation of synovial and ascitic fluids with the Advia 2120 hematology analyzer.

OBJECTIVES: The purpose of this study was to determine if the Advia 2120 hematology analyzer (Siemens Healthcare Diagnostics, Deerfield, IL) can accurately quantify both WBCs and the proportion of neutrophils from synovial and ascitic body fluids. METHODS: We analyzed 60 samples on the Advia and compared the results with manual counts and smear reviews. We also assessed the effect of adding hyaluronidase to the samples. WBC counts and the proportion of neutrophils reported by the hematology analyzer were harmonized and highly correlated with manual counts and fluid smear reviews. RESULTS: The addition of hyaluronidase to the synovial fluid consistently increased the WBC counts on both manual and automated analysis (P < .001). CONCLUSIONS: We conclude that the Advia hematology analyzer can be used for WBC and neutrophil counting of cells in synovial and ascitic fluids. Hyaluronidase should be added before manual or automated counting of cells in synovial fluids.

Significant, quantifiable differences exist between IgG subclass standards WHO67/97 and ERM-DA470k and can result in different interpretation of results.

OBJECTIVES: Accurate measurement of IgG subclass (IgGSc) levels are essential to aid in the diagnosis of disease states such as primary immunodeficiencies. However, there is no single standardisation of nephelometric and turbidimetric assays for these analytes and two reference materials have been utilised. We expand on previous reports and present data from a multi-site analysis that both identifies and quantitatively defines the differences in calibration resulting from the use of different reference materials. DESIGN AND METHODS: IgGSc antibodies in the serum specimens and reference materials were measured according to the manufacturers' instructions using commercially available IgGSc assays or components. RESULTS: Data from four independent sites showed that in spite of the different commercial suppliers of IgGSc assays calibrating to different reference materials, ERM-DA470k and WHO67 /97, the resulting calibrations were comparable for IgG1 and IgG2. However, for IgG3 and IgG4 the calibrations were significantly different. The use of assay specific normal ranges should compensate for these calibration differences, however, the two manufacturers' assays can give differing clinical classifications. The agreement between the different manufacturers' IgGSc assays was between 85.1% and 95.8% for all IgGSc assays, the discordance of sample classification for IgG1 and IgG2 assays was approximately 12% and 15% respectively, whilst that for IgG3 and IgG4 was 4% and 13% respectively. CONCLUSION: We discuss the similarities and differences between assays that utilise the different reference materials.

Vitamin D supplementation for patients with multiple sclerosis treated with interferon-beta: a randomized controlled trial assessing the effect on flu-like symptoms and immunomodulatory properties.

BACKGROUND: Flu-like symptoms (FLS) are common side effects of interferon beta (IFN-ß) treatment in patients with Multiple Sclerosis (PwMS) and are associated with post-injection cytokine surge. We hypothesized that vitamin D3 supplementation would ameliorate FLS by decreasing related serum cytokines' levels. METHODS: In a randomized, double blind study of 45 IFNß-treated PwMS, 21 patients were assigned to 800 IU of vitamin D3 per day (low dose), while 24 patients received 4,370 IU per day (high dose) for one year. FLS were assessed monthly by telephonic interviews. Serum levels of 25-hydroxy-D (25-OH-D), calcium, PTH, IL-17, IL-10 and IFN-γ were measured periodically. EDSS, relapses, adverse events and quality of life (QoL) were documented. RESULTS: 25-OH-D levels increased to a significantly higher levels and PTH levels decreased in the high dose group. There was no significant change in FLS. IL-17 levels were significantly increased in the low dose group, while patients receiving high dose vitamin D had a heterogeneous IL-17 response. No significant differences in relapse rate, EDSS, QoL, serum IL-10 and IFNγ were found. Hypercalcemia or other potential major adverse events were not observed. CONCLUSION: Vitamin D supplementation to IFN-ß treated PwMS, at the doses used, seems safe and associated with dose-dependent changes in IL-17 serum levels, while not affecting IFN-ß related FLS. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT01005095.