Developing Threshold Parameters to Administer Live Vaccines in Cellular Immunodeficiency: A Survey of Practicing Clinical Immunologists

Live vaccines are contraindicated in patients with severe cellular immunodeficiencies while guidelines regarding the administration of live vaccines in patients with more mild disease are ill-defined. We sought to decipher different parameters used by practicing immunologists for the administration of live vaccines in cellular immunodeficiency patients. A 27-question survey assessing clinical and laboratory threshold parameters used in the administration of live vaccines to immunodeficient patients was distributed to practicing clinicians specializing in immune deficiencies. There were 83 survey respondents, 65% identified as female, and 71% were based in the United States. Allergy / Immunology and Immunodeficiency were the most common identified specialties, accounting for 84% of respondents. Most clinicians did administer live vaccines to patients with humoral (54/67; 80.6%), cellular (41/67; 61.2%), and combined diseases (37/67; 55.2%) . Most clinicians who reported giving live vaccines to patients with immune deficiencies considered a threshold CD4 count of ≥ 400 cells/mm3 (MMR 48/60 [80%], Varicella 42/53 [79%], Rotavirus 40/45 [88.89%]), a CD8 count of ≥ 250 cells/mm3 (MMR 30/39 [76.92%], Varicella 29/37 [78.34%], Rotavirus 27/34 [79.41%]), and normal mitogen function (MMR 44/53 [83.02%], Varicella 40/48 [83.33%], Rotavirus 37/40 [92.5%]). Using these survey results, we propose a treatment threshold of using CD4 count of ≥ 400 cells/mm3, a CD8 count of ≥ 250 cells/mm3, and normal lymphocyte proliferative responses to mitogen. Future studies are needed to determine clinical efficacy and safety using these thresholds.

Evaluating Efficacy of Fumagilin-B® Against Nosemosis and Tracking Seasonal Trends of Nosema spp. in Nova Scotia Honey Bee Colonies

The efficacy of the antimicrobial Fumagilin-B® against nosemosis was evaluated in both spring and autumn feeding treatments following label directions in seventy-two honey bee (Apis mellifera) colonies across three apiaries in Nova Scotia, Canada. The seasonal trend of Nosema spp. spore loads was also tracked in these same colonies throughout a thirteen-month period (February 2018 – March 2019). We found the spring Fumagilin-B® treatment to be effective at significantly suppressing Nosema spp. spore levels below the recommended treatment threshold. There was no effect of Fumagilin-B® treatment in the autumn based on low spore levels at this time. We detected a drastic increase in Nosema spp. spore loads as May progressed but a decline in spores in summer (June–September). By October, there was another increase in spore levels, but this increase did not exceed the economic treatment threshold. Across seventeen collection periods in both control and Fumagilin-B® colonies, 74% (25) of samples tested positive for Nosema ceranae, while 26% (9) contained no Nosema spp. spores. No Nosema apis spores were detected during this trial. Our results indicate that Fumagilin-B® is an effective management practice in the spring, but colonies should still be monitored in the autumn. Our data also support that the Nosema species profile is shifting to be exclusively N. ceranae and the treatment threshold for Fumagilin-B® may need to be updated to reflect this, as the threshold was originally developed for N. apis.

Iraqi Dentists' Risk-Based Restorative Treatment Decisions

Objective: The aim of the present study was to investigate the decision-making by Iraqi dentists concerning the use of restorations in the treatment of dental caries. Methods: A cross-sectional study based on a self-administered questionnaire was conducted among 159 dentists who worked in public health sector in Baghdad during summer of 2016. A questionnaire which obtained information on age, attitude, knowledge and barriers, in addition to two scenarios designed to investigate dentists' restorative treatment threshold, was used. Paper patient cases (PPCs) were indicated high-risk (HR) and low-risk (LR) patients were also provided. Dentists were asked to point out at when they will start restoration of the teeth according to each PPC. Results: After checking for completeness, 90 questionnaires remained for data analysis. For HR scenario: Dentists with medium and high barrier scores (74.2%), and those with low and medium preventive attitude (78.6%) showed the lower scores in restorative treatment threshold. In LR scenario, we found an interaction between age and other predictors. Dentists ≤40 years old made better preventive decisions. Conclusion: The present study showed that age and good preventive attitude play an important role in making the restorative decision by dentists. Continuing education programs must be provided for Iraqi dentists to improve their preventive treatment decisions.

SAT0479 IMPACT OF TRABECULAR BONE SCORE ON INTERVENTION THRESHOLD FOR BONE SPARING THERAPY IN PATIENTS REFERRED FOR BONE MINERAL DENSITY

Background:Trabecular bone score (TBS) is an index of skeletal quality that has been validated as an independent risk factor for fracture and incorporated into fracture risk assessment (FRAX). TBS provides information on bone microarchitecture not captured from standard bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DXA). Nonetheless, the clinical implications of using TBS in routine practice are not yet fully understood and warrant further evaluation.Objectives:To determine whether lumbar TBS can have an impact on clinician’s treatment threshold derived from DXA and clinical risk factors: does the addition of TBS to DXA measurements make the clinician more or less likely to recommend bone sparing therapy?Methods:A cross-sectional study at a tertiary metabolic bone centre in the West Midlands region of England. Three expert metabolic bone physicians, two rheumatologists and one elderly care, assessed consecutive patients referred for a DXA scan ± clinic review and provided treatment recommendations with and without TBS. Patients ≥ 18 years old with BMI of 15-37 who were not on bone sparing therapy were considered eligible. TBS was defined according to T-score as normal (T-score ≥ -1), moderate (-1 > T-score ≥ -2.5) or degraded (T-score ≤ -2.5). TBS groups were stratified by BMD T-scores (normal, osteopenia, or osteoporosis) using minimum T-score of total hip, femoral neck, and spine to identify categories in which TBS may be of more clinical use. The main outcome measure was the proportion of change in clinician’s treatment threshold between BMD alone and BMD plus TBS. The difference was assessed for significance using Chi-square test. Additionally, the change in UK National Osteoporosis Guideline Group (NOGG) threshold was also assessed using TBS-adjusted FRAX scores. Correlations between BMD-TBS strata and the change in intervention threshold (yes/no) were carried out using Spearman test.Results:540 patients were analysed. The inclusion of TBS resulted in 8.2% change in clinician’s treatment threshold (p <0.001) shifting the outcome 6.5 % for and 1.7 % against treatment. More than half of the cases in which the clinical decision was changed were for patients with osteopenia and degraded TBS (significant correlation; P <0.001). NOGG intervention threshold was changed in 7.4% of the cases (P<0.001); 6.1% for and 1.3% against treatment. 37.5% of NOGG changed outcome was related to osteopenia with degraded TBS (p<0.001). Kappa agreement between the clinician and NOGG was fair at 0.42 (p<0.001).Conclusion:These results demonstrate that using TBS in routine clinical practice is most likely to impact treatment decision in patients with osteopenia who have compromised bone microarchitecture. Incorporating TBS in routine DXA scans may lead to a net increase in bone protective therapy of approximately 5%. It is unknown whether adopting such an approach universally can reduce future fracture risk, and prospective studies are needed to address this question.References:[1]Hans D et al. J Bone Miner Res. 2011;26(11):2762-9.[2]McCloskey EV et al. Calcif Tissue Int. 2015;96(6):500-9.Table 1.Demographic and baseline characteristics (n = 540)Female470 (87%)Age (years)68.1 ± 11.6Body mass index (BMI)26.2 ± 4.6Femoral neck T-score-1.80 ± 1.04Total hip T-score-1.32 ± 1.07Lumbar spine T-score-1.37 ± 1.42Lumbar spine TBS1.32 ± 0.13Major osteoporotic fractures238 (44%)Spinal fractures81 (15%)FRAX major osteoporotic fracture14.43 ± 9.03FRAX hip fracture4.60 ± 6.20TBS-adjusted FRAX major osteoporotic fracture13.82 ± 8.80TBS-adjusted FRAX hip fracture4.45 ± 5.73Figure 1.Distribution of changed clinical treatment threshold in normal, moderate, and degraded TBS according to BMD T-scoreAcknowledgments:Bone density unit &Rheumatology team, Robert Jones and Agnes Hunt Orthopaedic HospitalDisclosure of Interests:None declared