RT-PCR genotyping assays to identify SARS-CoV-2 variants in England in 2021: a design and retrospective evaluation study

BACKGROUND

Whole-genome sequencing (WGS) is the gold standard diagnostic tool to identify and genetically characterise emerging pathogen mutations (variants), but cost, capacity, and timeliness limit its use when large populations need rapidly assessing. We assessed the potential of genotyping assays to provide accurate and timely variant information at scale by retrospectively examining surveillance for SARS-CoV-2 variants in England between March and September, 2021, when genotyping assays were used widely for variant detection.

METHODS

We chose a panel of four RT-PCR genotyping assays to detect circulating variants of SARS-COV-2 in England and developed a decision algorithm to assign a probable SARS-CoV-2 variant to samples using the assay results. We extracted surveillance data from the UK Health Security Agency databases for 115 934 SARS-CoV-2-positive samples (March 1-Sept 6, 2021) when variant information was available from both genotyping and WGS. By comparing the genotyping and WGS variant result, we calculated accuracy metrics (ie, sensitivity, specificity, and positive predictive value [PPV]) and the time difference between the sample collection date and the availability of variant information. We assessed the number of samples with a variant assigned from genotyping or WGS, or both, over time.

FINDINGS

Genotyping and an initial decision algorithm (April 10-May 11, 2021 data) were accurate for key variant assignment: sensitivities and PPVs were 0·99 (95% CI 0·99-0·99) for the alpha, 1·00 (1·00-1·00) for the beta, and 0·91 (0·80-1·00) for the gamma variants; specificities were 0·97 (0·96-0·98), 1·00 (1·00-1·00), and 1·00 (1·00-1·00), respectively. A subsequent decision algorithm over a longer time period (May 27-Sept 6, 2021 data) remained accurate for key variant assignment: sensitivities were 0·91 (95% CI 0·74-1·00) for the beta, 0·98 (0·98-0·99) for the delta, and 0·93 (0·81-1·00) for the gamma variants; specificities were 1·00 (1·00-1·00), 0·96 (0·96-0·97), and 1·00 (1·00-1·00), respectively; and PPVs were 0·83 (0·62-1·00), 1·00 (1·00-1·00), and 0·78 (0·59-0·97), respectively. Genotyping produced variant information a median of 3 days (IQR 2-4) after the sample collection date, which was faster than with WGS (9 days [8-11]). The flexibility of genotyping enabled a nine-times increase in the quantity of samples tested for variants by this method (from 5000 to 45 000).

INTERPRETATION

RT-PCR genotyping assays are suitable for high-throughput variant surveillance and could complement WGS, enabling larger scale testing for known variants and timelier results, with important implications for effective public health responses and disease control globally, especially in settings with low WGS capacity. However, the choice of panels of RT-PCR assays is highly dependent on database information on circulating variants generated by WGS, which could limit the use of genotyping assays when new variants are emerging and spreading rapidly.

FUNDING

UK Health Security Agency and National Institute for Health Research Health Protection Research Unit in Emergency Preparedness and Response.

Using paleoecological data to inform decision making: A deep-time perspective

Latest climate models project conditions for the end of this century that are generally outside of the human experience. These future conditions affect the resilience and sustainability of ecosystems, alter biogeographic zones, and impact biodiversity. Deep-time records of paleoclimate provide insight into the climate system over millions of years and provide examples of conditions very different from the present day, and in some cases similar to model projections for the future. In addition, the deep-time paleoecologic and sedimentologic archives provide insight into how species and habitats responded to past climate conditions. Thus, paleoclimatology provides essential context for the scientific understanding of climate change needed to inform resource management policy decisions. The Pliocene Epoch (5.3–2.6 Ma) is the most recent deep-time interval with relevance to future global warming. Analysis of marine sediments using a combination of paleoecology, biomarkers, and geochemistry indicates a global mean annual temperature for the Late Pliocene (3.6–2.6 Ma) ∼3°C warmer than the preindustrial. However, the inability of state-of-the-art climate models to capture some key regional features of Pliocene warming implies future projections using these same models may not span the full range of plausible future climate conditions. We use the Late Pliocene as one example of a deep-time interval relevant to management of biodiversity and ecosystems in a changing world. Pliocene reconstructed sea surface temperatures are used to drive a marine ecosystem model for the North Atlantic Ocean. Given that boundary conditions for the Late Pliocene are roughly analogous to present day, driving the marine ecosystem model with Late Pliocene paleoenvironmental conditions allows policymakers to consider a future ocean state and associated fisheries impacts independent of climate models, informed directly by paleoclimate information.

Linking Climate Change Adaptation Strategies and Nutrition Outcomes: A Conceptual Framework

BACKGROUND

The relationship between climate adaptation strategies and nutrition security is poorly understood and often unclear. Although several adaptation strategies have been implemented to mitigate the impact of climate change, there is still a lack of conclusive evidence or studies on the interrelationships between adopted climate change adaptation strategies and nutrition outcomes.

OBJECTIVE

This study aimed at developing a conceptual framework that links climate change, adaptation strategies and nutrition and show the indicators that can be used to assess the impact of climate adaptation strategies on nutrition.

METHODOLOGY

The proposed conceptual framework was developed through a literature review.

RESULTS

A generic conceptual framework that could be used to assess the impact of adopted climate change adaptation strategies on nutrition outcomes was developed. The framework consists of 5 key elements: Agro-food system, context characteristics, adaptation strategies, climatic shocks and stress, and system output. The principles used in designing the conceptual framework include systems approach, contingency theory, and system output.

CONCLUSION

The developed framework offers a channel to evaluate adopted climate change adaptation strategies and their impact on nutrition outcomes. Such a conceptual framework can also be used in selecting and identifying more suitable climate adaptation strategies given specific contextual environments.

Erratum: Azimuthal Anisotropy of K_{S}^{0} and Λ+Λ[over ¯] Production at Midrapidity from Au+Au Collisions at sqrt[s]_{NN}=130 GeV [Phys. Rev. Lett. 89, 132301 (2002)]

This corrects the article DOI: 10.1103/PhysRevLett.89.132301.

Erratum: Azimuthal Anisotropy at the Relativistic Heavy Ion Collider: The First and Fourth Harmonics [Phys. Rev. Lett. 92, 062301 (2004)]

This corrects the article DOI: 10.1103/PhysRevLett.92.062301.

Assessing Mealtime Macronutrient Content: Patient Perceptions Versus Expert Analyses via a Novel Phone App

Background: People with type 1 diabetes estimate meal carbohydrate content to accurately dose insulin, yet, protein and fat content of meals also influences postprandial glycemia. We examined accuracy of macronutrient content estimation via a novel phone app. Participant estimates were compared with expert nutrition analyses performed via the Remote Food Photography Method© (RFPM©). Methods: Data were collected through a novel phone app. Participants were asked to take photos of meals/snacks on the day of and day after scheduled exercise, enter carbohydrate estimates, and categorize meals as low, typical, or high protein and fat. Glycemia was measured via continuous glucose monitoring. Results: Participants (n = 48) were 15-68 years (34 ± 14 years); 40% were female. The phone app plus RFPM© analysis captured 88% ± 29% of participants' estimated total energy expenditure. The majority (70%) of both low-protein and low-fat meals were accurately classified. Only 22% of high-protein meals and 17% of high-fat meals were accurately classified. Forty-nine percent of meals with <30 g of carbohydrates were overestimated by an average of 25.7 ± 17.2 g. The majority (64%) of large carbohydrate meals (≥60 g) were underestimated by an average of 53.6 ± 33.8 g. Glycemic response to large carbohydrate meals was similar between participants who underestimated or overestimated carbohydrate content, suggesting that factors beyond carbohydrate counting may impact postprandial glycemic response. Conclusions: Accurate estimation of total macronutrients in meals could be leveraged to improve insulin decision support tools and closed loop insulin delivery systems; development of tools to improve macronutrient estimation skills should be considered.

The Efficacy of Basal Rate and Carbohydrate Ratio Learning Algorithm for Closed-Loop Insulin Delivery (Artificial Pancreas) in Youth with Type 1 Diabetes in a Diabetes Camp

Background: Optimizing programmed basal rates and carbohydrate ratios may improve the performance of the artificial pancreas. We tested, in a diabetes camp, the efficacy of a learning algorithm that updates daily basal rates and carbohydrate ratios in the artificial pancreas. Materials and Methods: We conducted a randomized crossover trial in campers and counselors aged 8-21 years with type 1 diabetes on pump therapy. Participants underwent 2 days of artificial pancreas alone and 6 days of artificial pancreas with learning. During the artificial pancreas with learning, programmed basal rates and carbohydrate ratios were updated daily based on the learning algorithm's recommendations. All algorithm recommendations were reviewed for safety by camp physicians. The primary outcome was the time in target range (3.9-10 mmol/L) of the last 2 days of each intervention. Results: Thirty-four campers (age 13.9 ± 3.9, hemoglobin A1c 8.3% ± 0.2%) were included. Ninety-six percent of algorithm recommendations were approved by the camp physicians. Participants were in closed-loop mode 74% of the time. There was no difference between interventions in time in target (55%-55%; P = 0.71) nor in hypoglycemia events (0.8-0.9 events per day; P = 0.63). This was despite changes in programmed basal rate ranging from -21% to +117%, and changes in breakfast, lunch, and supper carbohydrate ratios from -17% to +40%, -36% to +37%, and -35% to +63%, respectively. Morever, postprandial hyperglycemia and hypoglycemia did not decrease in participants whose carbohydrate ratios were decreased (more insulin boluses) and increased (less insulin boluses), respectively. Conclusions: In camp settings, despite adjustments to programmed basal rates and carbohydrate ratios, the learning algorithm did not change glycemia, which may point toward limited effect of these adjustments in environments with large day-to-day variability in insulin needs. Longer randomized studies in real-world settings are required to further assess the efficacy of automatic adjustments of programmed basal rates and carbohydrate ratios.

Leveraging a Big Dataset to Develop a Recurrent Neural Network to Predict Adverse Glycemic Events in Type 1 Diabetes

Patients with type 1 diabetes (T1D) do not produce their own insulin. They must continuously monitor their glucose and make decisions about insulin dosing to avoid the consequences of adverse glucose excursions. Continuous glucose monitoring (CGM) systems and insulin pumps are state-of-the-art systems that can help people with T1D manage their glucose. Accurate glucose prediction algorithms are becoming critical components of CGM systems that can help people with T1D proactively avoid the occurrence of impending hyperglycemia and hypoglycemia events. We present Glucop30, a robust data-driven glucose prediction model that is trained on a big dataset (27,466 days) to forecast glucose concentration along a short-term prediction horizon of 30 minutes. Our proposed prediction method is composed of (i) a recurrent neural network with long-short-term-memory (LSTM) units that predicts the general trend of future glucose levels, followed by (ii) a patient-specific smoothing error correction step that accounts for inter- and intra-patient glucose variability. We retrospectively test our proposed method on a clinical dataset obtained from 10 T1D insulin pump users who were continuously monitored during a 4-week trial under free-living conditions (255 days), and assess the impact of the size of the training set on the accuracy of the proposed model. In addition, we report on the accuracy of our method when both CGM and insulin data are used for prediction; however we discovered that adding insulin as an additional input feature improves prediction accuracy by only 1%. Glucop30 achieves leading performance as measured by the RMSE of 7.55 (SD = 2.20 mg/dL) and MAE of 4.89 (SD = 1.43 mg/dL) for an effective prediction horizon of 27.50 (SD = 2.64) minutes. Moreover, Glucop30 accurately anticipates the occurrence of 97.79 (SD = 5.35)% of hyperglycemia events (glucose > 180 mg/dL), and 90.87 (SD = 6.79)% of hypoglycemia events (glucose < 70 mg/dL) with remarkably few false alerts (1 and 2 false alarms per week for hypoglycemia and hyperglycemia events, respectively).

Case Report: Brachial Neuritis in a Patient with Epstein Barr Virus

A 41 year-old man, recently returned from Thailand, presented with bilateral shoulder pain and weakness, fever greater than 38 degrees and coryzal symptoms. He had no significant past medical history. He had abnormal liver function tests and an abnormal electromyogram of his right upper limb. He was diagnosed with acute Epstein Barr virus infection, however cerebrospinal fluid was negative for the virus. At follow up after three months, the patient had persistent weakness of his right upper limb. The literature suggests neurological features present in up to 7.5% of patients with Epstein Barr virus, although argues this is underestimated with the virus often being overlooked as a cause of neurological symptoms.

Autopsy Findings in an Elderly Man Suffering from Severe von Willebrand’s Disease

A platelet derived growth factor released following platelet adhesion to the subendothelium of damaged arteries may promote the development of atherosclerotic lesions. Consequently patients with von Willebrand’s disease in whom platelet adhesion is abnormal may be protected from atherosclerosis. This possibility was investigated by performing an autopsy study on an elderly patient who had suffered from severe von Willebrand’s disease. Extensive atherosclerotic lesions were found at post mortem suggesting that platelets may not play a clinically significant role in the causation of atherosclerosis

A Store-and-Forward Tele-Audiology Solution to Promote Efficient Screenings for Ototoxicity during Cisplatin Cancer Treatment

BACKGROUND

Tele-audiology improves access, controls cost, and improves efficiency of many aspects within health care. We have developed and validated a device, the ototoxicity identification device (OtoID), which enables remote hearing monitoring by a patient during chemotherapy treatment. Aspects of the design such as patient self-testing and texting of results to the audiology clinic are important features of this device.

PURPOSE

The purpose of this article is to present the efficacy and effectiveness of the OtoID hearing screener.

RESEARCH DESIGN

A repeated measures design was used in this study.

STUDY SAMPLE

Twenty-one veterans undergoing cisplatin chemotherapy were recruited in this study.

DATA COLLECTION AND ANALYSIS

Participants were tested using the OtoID at each cisplatin treatment by an audiologist using the manual mode of test and the participant using the automated mode of test. Test sensitivity and specificity were developed from the detection (yes/no) of an American Speech-Language-Hearing Association (ASHA) change in hearing.

RESULTS

The OtoID had a test sensitivity of 80.6% and specificity of 85.3%. A logistic regression model analysis of the probability of an ASHA shift identified by the automated OtoID was conducted. Separate models were fit to establish effects of age, average baseline thresholds in the sensitive range for ototoxicity (SRO), and dose of cisplatin on the probability of a positive hearing change result. Interactions were also included to evaluate these effects on the sensitivity and false-positive rates of the automated test. Results indicated no statistically significant effects of age, of baseline hearing in the SRO frequencies, or of cisplatin dose.

CONCLUSIONS

The OtoID automated test can be recommended for use. The automated test provides significant personnel efficiencies. The modem with simple text messaging function recently added to the device improves on these efficiencies.

An Exploration of the Effects of Mentor-Apprentice Programs on Mentors' and Apprentices' Wellbeing

Increasingly, adult Indigenous language learners are being identified as the “missing generation” of learners who hold great potential to contribute to the revival of Indigenous languages by acting as the middle ground between Elders, children, and youth within their communities. Our research project NEȾOLṈEW̱ “one mind, one people” studied adult Indigenous language learning through the popular Mentor-Apprentice Program method. Over a 2-year period, our team conducted interviews and focus groups with participants involved in a Mentor-Apprentice type program in British Columbia, Canada. While our primary interest was to document the successes and challenges of the Mentor-Apprentice Program method for adult Indigenous language learning, we also included interview questions that gave participants an opportunity to share how participating in such a program affected them. During data analysis, we noticed repeating comments from participants about how their involvement with a Mentor-Apprentice Program impacted their own and their community’s wellbeing; 6 exploratory themes were identified. Although studies have reported protective effects of Indigenous language use on health, health-related outcomes of language revitalization efforts remain underexplored. In addition to discussing the exploratory themes that arose from the study, our paper also proposes that these themes can inform future research in investigating the links between language revitalization and wellbeing.

Assessing recent warming using instrumentally homogeneous sea surface temperature records

Sea surface temperature (SST) records are subject to potential biases due to changing instrumentation and measurement practices. Significant differences exist between commonly used composite SST reconstructions from the National Oceanic and Atmospheric Administration's Extended Reconstruction Sea Surface Temperature (ERSST), the Hadley Centre SST data set (HadSST3), and the Japanese Meteorological Agency's Centennial Observation-Based Estimates of SSTs (COBE-SST) from 2003 to the present. The update from ERSST version 3b to version 4 resulted in an increase in the operational SST trend estimate during the last 19 years from 0.07° to 0.12°C per decade, indicating a higher rate of warming in recent years. We show that ERSST version 4 trends generally agree with largely independent, near-global, and instrumentally homogeneous SST measurements from floating buoys, Argo floats, and radiometer-based satellite measurements that have been developed and deployed during the past two decades. We find a large cooling bias in ERSST version 3b and smaller but significant cooling biases in HadSST3 and COBE-SST from 2003 to the present, with respect to most series examined. These results suggest that reported rates of SST warming in recent years have been underestimated in these three data sets.

Comparison of physical function and falls among women with persistent symptoms of chemotherapy-induced peripheral neuropathy

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Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a side effect of cancer treatment that may persist and impact physical function. Studies that quantify functional consequences associated with CIPN in post-treatment cancer survivors are rare, based on self-report, or use small samples. The purpose of this study was to compare objective and self-report measures of physical function, gait patterns, and falls between women cancer survivors with or without symptoms of CIPN. Methods: Baseline assessments from 678 women cancer survivors enrolled in exercise trials were available for analysis. Women who self-reported symptoms of CIPN (CIPN+) were compared to asymptomatic women (CIPN-) on the following: maximal leg press strength (LPmax); timed chair stand (CS), physical performance battery (PPB), gait patterns (speed (SP), step number (SN), stride length (SL), base of support (BOS), % time in double support (%DS)), self-report physical function (PF) and disability (DIS), and falls in the past year (% fallers). Group comparisons were made using analysis of covariance, adjusting for time since diagnosis and cancer site (breast or other). Results: After excluding women who had diabetes, were premenopausal at cancer diagnosis or had not received chemotherapy, 462 cases were analyzed (age: 62±6yrs; time since diagnosis: 5.8±4.1yrs). CIPN+ (N = 210) and CIPN- (N = 252) groups significantly differed on all measures (*p < 0.05; **p < 0.01), except maximal leg strength and base of support during a usual walk, with worse performance for CIPN+. Conclusions: In our sample of women cancer survivors, 45% had symptoms of CIPN an average of 6 years post treatment and significantly worse physical function, altered gait patterns and more falls than asymptomatic women. CIPN should be addressed early in treatment and strategies to improve function and mobility and prevent falls need to be tested. [Table: see text]

Towards biolubricant compatible vegetable oils by pore mouth hydrogenation with shape-selective Pt/ZSM-5 catalysts

Pore mouth hydrogenation of vegetable oil with Pt/ZSM-5 is confirmed by the similar intermediately melting product selectivity for various crystal sizes.

Effect of Repeated Glucagon Doses on Hepatic Glycogen in Type 1 Diabetes: Implications for a Bihormonal Closed-Loop System

OBJECTIVE

To evaluate subjects with type 1 diabetes for hepatic glycogen depletion after repeated doses of glucagon, simulating delivery in a bihormonal closed-loop system.

RESEARCH DESIGN AND METHODS

Eleven adult subjects with type 1 diabetes participated. Subjects underwent estimation of hepatic glycogen using (13)C MRS. MRS was performed at the following four time points: fasting and after a meal at baseline, and fasting and after a meal after eight doses of subcutaneously administered glucagon at a dose of 2 µg/kg, for a total mean dose of 1,126 µg over 16 h. The primary and secondary end points were, respectively, estimated hepatic glycogen by MRS and incremental area under the glucose curve for a 90-min interval after glucagon administration.

RESULTS

In the eight subjects with complete data sets, estimated glycogen stores were similar at baseline and after repeated glucagon doses. In the fasting state, glycogen averaged 21 ± 3 g/L before glucagon administration and 25 ± 4 g/L after glucagon administration (mean ± SEM) (P = NS). In the fed state, glycogen averaged 40 ± 2 g/L before glucagon administration and 34 ± 4 g/L after glucagon administration (P = NS). With the use of an insulin action model, the rise in glucose after the last dose of glucagon was comparable to the rise after the first dose, as measured by the 90-min incremental area under the glucose curve.

CONCLUSIONS

In adult subjects with well-controlled type 1 diabetes (mean A1C 7.2%), glycogen stores and the hyperglycemic response to glucagon administration are maintained even after receiving multiple doses of glucagon. This finding supports the safety of repeated glucagon delivery in the setting of a bihormonal closed-loop system.

Systems medicine, personalized health and therapy

The 7th Santorini Conference was held in Santorini, Greece, and brought together 200 participants from 40 countries in several continents, including Europe, USA but also Japan, Korea, Brazil and South Africa. The attendees had the opportunity to: listen to 60 oral presentations; participate in two lunch symposia; look at 103 posters, which were divided in two groups ('systems medicine and environment' and 'pharmacogenomics and cancer') and attend a dedicated exhibition with six companies. The meeting was organized by the Institut National de la Santé et de la Recherche Médicale (INSERM) U1122; IGE-PCV and by 'Biologie Prospective' with the collaboration of the European Society of Pharmacogenomics and Theranostics (ESPT), under the auspices of international organizations (e.g., International Federation of Clinical Chemistry and Laboratory medicine [IFCC], European Federation of Clinical Chemistry and Laboratory Medicine [EFLM], European Diagnostic Manufacturers Association [EDMA], Federation of European Pharmacological Societies [EPHAR], European Science Foundation [ESF]). The 3 days of the conference stimulated intensive discussions on systems biology and the influence of omics technologies on personalized health. Sixty speakers were invited or selected from early abstracts and gave presentations on the following topics: From systems biology to systems medicine/pharmacology; Omics/translating pharmacogenomics/proteomic biomarkers/metabolomics; Human nutrition and health/personalized medicine. We are summarizing here the main topics and presentations, according to the successive sessions.

Nutritional contribution of street foods to the diet of people in developing countries: a systematic review

OBJECTIVE

To review studies examining the nutritional value of street foods and their contribution to the diet of consumers in developing countries.

DESIGN

The electronic databases PubMed/MEDLINE, Web of Science, Cochrane Library, Proquest Health and Science Direct were searched for articles on street foods in developing countries that included findings on nutritional value.

RESULTS

From a total of 639 articles, twenty-three studies were retained since they met the inclusion criteria. In summary, daily energy intake from street foods in adults ranged from 13 % to 50 % of energy and in children from 13 % to 40 % of energy. Although the amounts differed from place to place, even at the lowest values of the percentage of energy intake range, energy from street foods made a significant contribution to the diet. Furthermore, the majority of studies suggest that street foods contributed significantly to the daily intake of protein, often at 50 % of the RDA. The data on fat and carbohydrate intakes are of some concern because of the assumed high contribution of street foods to the total intakes of fat, trans-fat, salt and sugar in numerous studies and their possible role in the development of obesity and non-communicable diseases. Few studies have provided data on the intake of micronutrients, but these tended to be high for Fe and vitamin A while low for Ca and thiamin.

CONCLUSIONS

Street foods make a significant contribution to energy and protein intakes of people in developing countries and their use should be encouraged if they are healthy traditional foods.

Economic consequences incurred by living kidney donors: a Canadian multi-center prospective study

Some living kidney donors incur economic consequences as a result of donation; however, these costs are poorly quantified. We developed a framework to comprehensively assess economic consequences from the donor perspective including out-of-pocket cost, lost wages and home productivity loss. We prospectively enrolled 100 living kidney donors from seven Canadian centers between 2004 and 2008 and collected and valued economic consequences ($CAD 2008) at 3 months and 1 year after donation. Almost all (96%) donors experienced economic consequences, with 94% reporting travel costs and 47% reporting lost pay. The average and median costs of lost pay were $2144 (SD 4167) and $0 (25th-75th percentile 0, 2794), respectively. For other expenses (travel, accommodation, medication and medical), mean and median costs were $1780 (SD 2504) and $821 (25th-75th percentile 242, 2271), respectively. From the donor perspective, mean cost was $3268 (SD 4704); one-third of donors incurred cost >$3000, and 15% >$8000. The majority of donors (83%) reported inability to perform usual household activities for an average duration of 33 days; 8% reported out-of-pocket costs for assistance with these activities. The economic impact of living kidney donation for some individuals is large. We advocate for programs to reimburse living donors for their legitimate costs.

Tuberculosis screening for long-term care: a cost-effectiveness analysis

SETTING

Long-term care facilities in Canada, a low tuberculosis (TB) incidence country.

OBJECTIVE

To compare the impact and cost-effectiveness of three screening strategies for TB on entry to long-term care: no screening, screening for latent tuberculous infection (LTBI) using the tuberculin skin test (TST) or screening for active disease with a chest X-ray.

DESIGN

Cost effectiveness analysis.

RESULTS

With the LTBI screening strategy, the number needed to screen to prevent one active case was 1410 and the cost per case averted was Canadian $109 913. The number needed to screen to prevent one case using the active screening strategy was 1266, and the cost per case averted was $672 298.

CONCLUSIONS

Our findings suggest that TB screening strategies on entry to long-term care are costly, with large numbers needed to screen. Screening with TST was more cost-effective than chest X-ray screening. Higher risk of reactivation of LTBI is associated with improved cost-effectiveness of screening. Short time horizons and test performance characteristics place limitations on screening programmes in this setting. Future considerations include the changing demographics of the institutionalised elderly.

Amyloidosis: A changing clinical perspective

Primary amyloidosis is a plasma cell dyscrasia characterised by excess production of abnormal immunoglobulin light chains with their subsequent accumulation in kidneys, heart, liver as well as gastrointestinal tract and bone marrow 1-21, 2. These tissue deposits take the form of a fibrillar protein which damages the involved organ in proportion to the extent of the infiltration and roughly parallels the duration of the disease. Most cases have evidence of the underlying lymphoplasmacytoid neoplasm recognisable in two ways. Firstly, the monoclone appears in the serum [2]. Secondly is a morphologically and immunohistochemically distinctive cellular infiltrate in the bone marrow [3] that has a specific microscopic and ultrastructural pattern 4-54, 5. Interestingly occasional patients, who survive long enough, may progress to multiple myeloma [6] but the correlation is variable [7].

Clonogenic growth patterns correlate with chemotherapy response in acute myeloid leukaemia

Cytosine arabinoside and anthracycline-containing regimens induce remission in upwards of 60% of previously untreated patients with adult acute myeloid leukaemia (AML). Despite this, in addition to primary drug resistance, the majority of these patients relapse. Reliable methods for uniformly recognising these two subgroups at presentation do not exist and therefore a further attempt has been made to relate in vitro toxicity, using a clonogenic assay, to clinical outcome. In 10 normal controls and 12 chemotherapy naïve cases, mononuclear cells harvested by density gradient separation were re-suspended at a concentration of 2 x 10(5)/ml and quadruplicates of 250 microl per well cultured in methycellulose containing foetal calf serum and phytohaemagglutinin stimulated leucocyte conditioned medium. Cell kill was determined for cytosine arabinoside, daunorubicin and etoposide either singly or in combination using both a pulsed and continuous exposure. Aggregates were scored after seven days and three distinct patterns recognised. The patients all received the same drugs in a standard protocol and achievement of complete remission correlated with growth pattern. The survival of normal marrow colony-forming cells or GM-CFUc and the leukemic equivalent designated L-CFUc were assessed and a sensitivity index (SI) determined as a ratio of these two values in which more reproducible results were found when the drug was continuously present. It is concluded that the microculture technique is feasible and clearly demonstrates chemotherapy effect but no correlation was demonstrated with clinical outcome. This is a negative pilot study and, as a means of recognising drug sensitivity or resistance, should be discarded in favour of currently available molecular techniques.

Splenectomy in haematology–A 5-year single centre experience

OBJECTIVE

To define indications and outcome in haematologic cases undergoing splenectomy.

STUDY DESIGN

A retrospective review of clinical records from consecutive patients having open or laparoscopic removal of the spleen in an academic centre in the private sector. Endpoints were survival, operating time, spleen size, histopathology, requirements for blood or related products complications and average costs.

RESULTS

In the total group (n = 69) there were two deaths. Referrals were for immune thrombocytopaenia (41%), acquired haemolytic anaemia (10%), myeloproliferative syndrome (9%), acute or chronic leukaemia (19%), lymphoma (13%) and a miscellaneous group (8%), comprising cholelithiasis, aplasia or as a diagnostic procedure for otherwise unexplained splenomegaly. An open midline approach was predicated by spleens greater than twice normal size and a history of any bleeding disorder. Here the mean operating time was 83 min (range 40-295) whereas for laparoscopy this was 251 min (range 181-272).

SUMMARY

Careful stratification between the two options facilitated optimum haemostasis and consequently reduced requirement for packed red cells and platelets. Neither underlying pathology nor the choice of treatment influenced morbidity or mortality. Overall local experience is consistent with published international standards of surgical practice. Outcome is directly proportional to the number of each procedure carried out by a single team, observance of consistent protocols for preoperative evaluation and standardized proactive management through the recovery period.

Tissue microarray in a subset of South African patients with DLBCL

Tissue samples from 93 de novo diffuse large B-cell lymphoma patients seen between 1995 and 2009 randomly receiving either standard combination chemotherapy (CHOP, n=48) or the identical program with rituximab (n=45) were subtyped using an investigational immunohistochemical (IHC) based tissue microarray (TMA) and contrasted to the approximately corresponding categories as defined either by Hans and associates using a three marker panel into germinal or non-germinal centre subtypes or by Choi and colleagues with two additional antibodies into germinal centre (GCB) or activated B-cells (ABC). Each of these primary subdivisions was further evaluated for expression of BCL2 and LMO2 both of which are recognised to predicate response. The addition of rituximab to the uniform drug regimen did not show any significant improvement in 5 years overall (63% versus 59%, p 0.68) or event-free survival (42% versus 39%, p 0.94), for CHOP versus R-CHOP comparisons. Similarly no differences were evident in subtype analysis. Interestingly however, when segregated on the Choi criteria, cytotoxic drugs alone showed a non-significant trend in improved survival (74% versus 55%, p 0.32) as well as event-free survival (44% versus 40%, p 0.42) for the germinal centre as opposed to the activated B-cell subtype. Nevertheless not even a small difference could be demonstrated in the presence of the anti CD 20 monoclonal antibody. According to Choi, both regimens (chemotherapy or immunotherapy antibody) revealed similar results to the Hans algorithm on 5 years OS as well as 3 year EFS when comparing GCB versus ABC or non-GCB subgroups. BCL2 and LMO2 marker expression of the respective immunohistochemical (IHC) subtype, despite small sample size, revealed the following. Analysis by Choi criteria on survival for BCL2, no matter for which subsets (GCB or ABC) or treatment modality (chemotherapy with or without the addition of rituximab) showed no difference in 5 years OS or EFS. In contrast, a significant difference for better EFS (p=0.0015) in the BCL2 positive group of the ABC subgroups subtypes treated with rituximab containing chemotherapy. For LMO2 similar results on survival outcome were seen thus showing no difference in 5 years OS or EFS - regardless of subtype or treatment modality. Also here, this was contrasted by better EFS (p=0.039) in the LMO2 positive group of ABC subtypes when treated with the rituximab containing regimen. The use of the IHC based TMA methodology has shown to be a simple, cost effective and a robust alternative to gene expression profiling (GEP) which is currently regarded as the gold standard for the classification in lymphomas. It provides a useful prognostic tool in stratifying DLBCL or other entities in future, even when frozen tissue samples are not available for GEP analysis. With the current budgetary limitations in South African public hospitals chemotherapy protocols for lymphoproliferative disorders exclude agents such as rituximab. Local therapeutic drug committees consider the approximately 15% overall survival benefit seen at 5 years for DLBCL when rituximab is added to combination chemotherapy as too marginal for justifying the arising additional expenses. Accordingly, demonstration that a specific molecular subtype accounts for superior outcome, when using these regimens, is needed. Such an option would provide convincing evidence for the use of immunochemotherapy in a resource constrained setting.