Disease Characteristics, Treatment and Survival for Oropharyngeal Squamous Cell Carcinoma of Elderly

PURPOSE/OBJECTIVE(S)

Incidence of oropharyngeal cancers (OP) has been increasing over the past few decades, mainly driven by human papilloma virus (HPV) associated cancers in younger men. However, a large number of OP patients in recent years are ≥65 years of age. We wanted to determine if there is a difference in outcomes in elderly patients with OP as compared to younger patients.

MATERIALS/METHODS

We queried our institutional prospectively maintained head and neck cancer database for patients with non-metastatic OP treated between 1/2009-6/2020. We excluded patients who did not receive any definitive treatment. We analyzed clinicopathological and treatment characteristics for elderly (age at diagnosis ≥65 years) compared to young (<65 years) across HPV subtypes. We also studied survival endpoints among age groups using Kaplan-Meier curves and log-rank test. Independent predictors were estimated using multivariate (MVA) Cox regression models for each HPV subtype.

RESULTS

We identified 340 patients who met our inclusion criteria: elderly 123 (36%) and young 213 (64%). The proportion of elderly HPV+ve patients showed an increasing trend over the years studied. Median age was 70 years (range 65-91) in elderly and 56 years (38-64) in young (p<0.001); and HPV+ve/-ve were 73.2/26.8% vs 74.6/25.3% for both age groups respectively (p = 0.86). Elderly patients had higher Charlson Comorbidity Index (CCI) and included more divorcees (p<0.05). There were more elderly current/former smokers (97% vs 82%; p = 0.007) within HPV-ve cases. Definitive radiotherapy (RT) +/- systemic therapy (CRT) was utilized in 73.2% (n = 249), while the remainder had surgery +/- adjuvant RT/CRT. There was no difference with age for OP subsite, 8th edition AJCC stage and treatment received except for more use of cetuximab (22.5% vs 10.2%; p<0.001) and weekly cisplatin (32.4% vs 25.8%; p<0.001) among elderly patients. After a median follow up of 5.24 years (IQR: 3.53), 3-year overall (OS) (HPV+ve: 85 vs 81%; HPV-ve: 39 vs 52%), locoregional free (LRFS) (HPV+ve: 86 vs 90%; HPV-ve: 67 vs 69%) and distant metastasis free (DMFS) survival (HPV+ve: 91 vs 90%; HPV-ve: 79 vs 81%) were all non-significant for elderly vs young respectively. On MVA, CCI and AJCC stage for HPV+ve; and smoking, T-stage and lymphovascular space invasion for HPV- were associated with OS. For HPV+ve, AJCC stage, adjuvant vs definitive RT and treatment in later years were predictive of better LRFS, whereas smoking index and extracapsular space invasion were deterministic for DMFS. Interestingly, outcomes among those who received cetuximab was similar to those who received concurrent cisplatin for all endpoints.

CONCLUSION

We did not note any significant difference in outcomes among elderly patients treated for OP when compared to the younger patients when multi-disciplinary head and neck cancer care is provided. This was noted even though a significantly larger proportion of elderly patients received cetuximab concurrent with RT as opposed to standard of care cisplatin.

Integrative analysis of non-small cell lung cancer patient-derived xenografts identifies distinct proteotypes associated with patient outcomes

Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths worldwide. Only a fraction of NSCLC harbor actionable driver mutations and there is an urgent need for patient-derived model systems that will enable the development of new targeted therapies. NSCLC and other cancers display profound proteome remodeling compared to normal tissue that is not predicted by DNA or RNA analyses. Here, we generate 137 NSCLC patient-derived xenografts (PDXs) that recapitulate the histology and molecular features of primary NSCLC. Proteome analysis of the PDX models reveals 3 adenocarcinoma and 2 squamous cell carcinoma proteotypes that are associated with different patient outcomes, protein-phosphotyrosine profiles, signatures of activated pathways and candidate targets, and in adenocarcinoma, stromal immune features. These findings portend proteome-based NSCLC classification and treatment and support the PDX resource as a viable model for the development of new targeted therapies.

With non-small cell lung cancer (NSCLC) being the leading cause of cancer deaths worldwide, the development of targeted therapies remains crucial. Here, the generation and multi-omics characterization of 137 NSCLC patient-derived xenografts provides a resource for potential classifications and targets.

Forearm High-Density Electromyography Data Visualization and Classification with Machine Learning for Hand Prosthesis Control

Electromyography offers a way to interface an amputee's resilient muscles to control a bionic prosthesis. While myoelectric prostheses are promising, user acceptance of these devices remain low due to a lack of intuitiveness and ease-of-use. Using a low-cost wearable flexible electrodes array, the proposed system leverages high-density surface electromyography (HD-EMG) and deep learning techniques to classify forearm muscle contractions. These techniques allow for increased intuitiveness and ease-of-use of a myoelectric control scheme with a single easy-to-install electrodes apparatus. This paper proposes a flexible electrodes array construction using standard printed circuit board manufacturing processes for low-cost and quick design-to-production cycles. HD-EMG dataset visualization with t-distributed Stochastic Neighbor Embedding (t-SNE) is introduced, and offline classification results of the wearable gesture recognition system for hand prosthesis control are validated on a group of 8 able-bodied subjects. Using a majority vote on 5 successive inferences, a median recognition accuracy of 98.61 % was obtained across the group for an 8 gestures set. For a 6 gestures set containing commonly used prosthesis positions, the median accuracy reached 99.57 % with the majority vote.

Effect of Expectation on Pain Processing: A Psychophysics and Functional MRI Analysis

Pain is a complex phenomenon that is highly modifiable by expectation. Whilst the intensity of incoming noxious information plays a key role in the intensity of perceived pain, this intensity can be profoundly shaped by an individual’s expectations. Modern brain imaging investigations have begun to detail the brain regions responsible for placebo and nocebo related changes in pain, but less is known about the neural basis of stimulus-expectancy changes in pain processing. In this functional magnetic resonance imaging study, we administered two separate protocols of the same noxious thermal stimuli to 24 healthy subjects. However, different expectations were elicited by different explanations to subjects prior to each protocol. During one protocol, pain intensities were matched to expectation and in the other protocol they were not. Pain intensity was measured continuously via a manually operated computerized visual analogue scale. When individuals expected the stimulus intensity to remain constant, but in reality it was surreptitiously increased or decreased, pain intensity ratings were significantly lower than when expectation and pain intensities were matched. When the stimulus intensities did not match expectations, various areas in the brain such as the amygdala, anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (dlPFC), and the midbrain periaqueductal gray matter (PAG) displayed significantly different patterns of activity compared to instances when stimulus intensity and pain expectations were matched. These results show that stimulus-expectancy manipulation of pain intensity alters activity in both higher brain and brainstem centers which are known to modulate pain under various conditions.

A Wearable Wireless Armband Sensor for High-Density Surface Electromyography Recording

This paper presents a portable and modular wireless multichannel sensor system for high-density surface electromyography (HD-sEMG) signals acquisition. Featuring low-power and high-quality off-the-shelf components such as the Intan Technologies RHD2132 digital electrophysiology interface chip, the current iteration of the proposed sensor system allows the recording of 32 surface electromyography (sEMG) channels, each at a sampling rate of 1 kHz, and a sample resolution of 16 bits. It features the RHD2132's typical input-referred noise of 2.4 μV_rms, with <; 15% variation with amplifier bandwidth as specified by the manufacturer, and a total power consumption of 49.5 mW. Data is sent in real-time to a base station using a 2.4-GHz industrial, scientific and medical (ISM) wireless link. Along with the recording platform, the integrated sensor system includes a dry surface electrodes array prototype directly built on a printed circuit board. Intended for complex muscles activity patterns detection on the forearm, the flexible 32 surface electrodes array is designed to be placed flat or to fit a curved area like the forearm in a hand gestures recognition prosthetic system. In such applications, this device will offer improved prosthesis control scheme intuitiveness and ease-of-use. Among other core features of the system are its compact, light-weight and easy to install physical design. The complete system fits on a 2 by 6.5 cm² printed circuit board mounted on a 7.6 by 11.8 cm² electrodes array. HD-sEMG user forearm output data collected with the system is presented with a proposed frequency-time-space cross-domain preprocessing method for visualization of HD-EMG data and building training datasets.

Thrombospondin-2 regulates extracellular matrix production, LOX levels, and cross-linking via downregulation of miR-29

Collagen fibrillogenesis and crosslinking have long been implicated in extracellular matrix (ECM)-dependent processes such as fibrosis and scarring. However, the extent to which matricellular proteins influence ECM protein production and fibrillar collagen crosslinking has yet to be determined. Here we show that thrombospondin 2 (TSP2), an anti-angiogenic matricellular protein, is an important modulator of ECM homeostasis. Specifically, through a fractionated quantitative proteomics approach, we show that loss of TSP2 leads to a unique ECM phenotype characterized by a significant decrease in fibrillar collagen, matricellular, and structural ECM protein production in the skin of TSP2 KO mice. Additionally, TSP2 KO skin displays decreased lysyl oxidase (LOX), which manifests as an increase in fibrillar collagen solubility and decreased levels of LOX-mediated fibrillar collagen crosslinking. We show that these changes are indirectly mediated by miR-29, a major regulator of ECM proteins and LOX, as miR-29 expression is increased in the TSP2 KO. Altogether, these findings indicate that TSP2 contributes to ECM production and assembly by regulating miR-29 and LOX.

Targeting the CDK4/6-Rb Pathway Enhances Response to PI3K Inhibition in PIK3CA-Mutant Lung Squamous Cell Carcinoma

PURPOSE

Lung squamous cell carcinoma (LUSC) is a major subtype of non-small cell lung cancer characterized by multiple genetic alterations, particularly PI3K pathway alterations which have been identified in over 50% of LUSC cases. Despite being an attractive target, single-agent PI3K inhibitors have demonstrated modest response in LUSC. Thus, novel combination therapies targeting LUSC are needed.

EXPERIMENTAL DESIGN

PI3K inhibitors alone and in combination with CDK4/6 inhibitors were evaluated in previously established LUSC patient-derived xenografts (PDX) using an in vivo screening method. Screening results were validated with in vivo expansion to 5 to 8 mice per arm. Pharmacodynamics studies were performed to confirm targeted inhibition of compounds.

RESULTS

Consistent with results from The Cancer Genome Atlas analysis of LUSC, genomic profiling of our large cohort of LUSC PDX models identified PI3K pathway alterations in over 50% of the models. In vivo screening using PI3K inhibitors in 12 of these models identified PIK3CA mutation as a predictive biomarker of response (<20% tumor growth compared with baseline/vehicle). Combined inhibition of PI3K and CDK4/6 in models with PIK3CA mutation resulted in greater antitumor effects compared with either monotherapy alone. In addition, the combination of the two drugs achieved targeted inhibition of the PI3K and cell-cycle pathways.

CONCLUSIONS

PIK3CA mutations predict response to PI3K inhibitors in LUSC. Combined PI3K and CDK4/6 inhibition enhances response to either single agents alone. Our findings provide a rationale for clinical testing of combined PI3K and CDK4/6 inhibitors in PIK3CA-mutant LUSC.

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong

INTRODUCTION

Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM.

METHODS

The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling.

RESULTS

In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years.

CONCLUSION

The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Helicase-like transcription factor expression is associated with a poor prognosis in Non-Small-Cell Lung Cancer (NSCLC)

Background

The relapse rate in early stage non-small cell lung cancer (NSCLC) after surgical resection is high. Prognostic biomarkers may help identify patients who may benefit from additional therapy. The Helicase-like Transcription Factor (HLTF) is a tumor suppressor, altered in cancer either by gene hypermethylation or mRNA alternative splicing. This study assessed the expression and the clinical relevance of wild-type (WT) and variant forms of HLTF RNAs in NSCLC.

Methods

We analyzed online databases (TCGA, COSMIC) for HLTF alterations in NSCLC and assessed WT and spliced HLTF mRNAs expression by RT-ddPCR in 39 lung cancer cell lines and 171 patients with resected stage I-II NSCLC.

Results

In silico analyses identified HLTF gene alterations more frequently in lung squamous cell carcinoma than in adenocarcinoma. In cell lines and in patients, WT and I21R HLTF mRNAs were detected, but the latter at lower level. The subgroup of 25 patients presenting a combined low WT HLTF expression and a high I21R HLTF expression had a significantly worse disease-free survival than the other 146 patients in univariate (HR 1.96, CI 1.17–3.30; p = 0.011) and multivariate analyses (HR 1.98, CI 1.15–3.40; p = 0.014).

Conclusion

A low WT HLTF expression with a high I21R HLTF expression is associated with a poor DFS.

Acquired 5-Oxoprolinuria (Pyroglutamic Acidaemia) as a Cause of Early High Anion Gap Metabolic Acidosis in Acute Massive Paracetamol Overdose

5-oxoprolinuria is an uncommon and under-recognised cause of early high anion gap metabolic acidosis after paracetamol overdose. We reported a 30-year-old Indian woman with history of chronic alcoholism who ingested 150 g crushed paracetamol tablets for suicide 14 hours before attendance to the A&E Department. Initial arterial blood gas showed a high anion gap metabolic acidosis with respiratory compensation. Serum paracetamol level reached 5004 umol/L and a prolonged course of N-acetylcysteine was given. She was complicated by hepatotoxicity and 5-oxoprolinuria (with laboratory confirmation) which reverted after antidote administration. There were no neurological and hepatic sequelae. In case of massive overdose, pathways of drug metabolism are altered prior to the centrilobular hepatic necrosis. A metabolic intermediate of gamma-glutamyl cycle, 5-oxoproline, accumulates upon saturation of endogenous glutathione store. The specific antidote N-acetylcysteine is the only definitive treatment. Prolonged course of antidote may be required in cases of massive overdose and treatment should be individualised. (Hong Kong j.emerg. med. 2011;18:264-270)

Transoral robotic surgery vs. radiotherapy for management of oropharyngeal squamous cell carcinoma - A systematic review of the literature

BACKGROUND

Intensity-modulated radiation therapy (IMRT) with or without concurrent chemotherapy is widely utilized for the treatment of oropharyngeal squamous cell carcinoma (OPSCC). However, due to significant acute and late toxicities there has been increasing interest in minimally invasive surgical approaches, particularly transoral robotic surgery (TORS) in an attempt to preserve patient quality of life while maintaining oncologic outcomes. The aim of this study was to review the current literature in order to compare primary IMRT versus TORS in the management of OPSCC.

METHODS

A MEDLINE search was conducted to identify studies reporting on the outcomes of TORS or IMRT in the treatment of OPSCC. Reference lists were also reviewed for relevant articles. Oncologic, functional, and quality of life data is summarized and discussed.

RESULTS

One hundred-ninety papers were identified through the MEDLINE search. An additional 52 papers were retrieved by hand searching the reference lists. Ultimately, 44 papers were identified that discussed outcomes after IMRT or TORS for OPSCC. No outcomes from randomized trials were identified.

CONCLUSION

No randomized trials comparing TORS versus IMRT to each other were identified. Uncontrolled reports from the current literature suggest comparable oncologic outcomes with TORS compared to IMRT and functional outcomes may be superior. However, the median follow-up was relatively short and the TORS studies included patients with earlier stage OPSCC on average compared to IMRT studies. Prospective, randomized controlled trials and direct, well-matched comparisons are needed to further elucidate the role for TORS in the treatment of oropharyngeal squamous cell carcinoma.

Cardiometabolic risk profile of participants with prediabetes diagnosed by HbA1c criteria in an urban Hong Kong Chinese population over 40 years of age

AIMS

To investigate the usefulness of the additional measurement of HbA1c , compared with performing only the oral glucose tolerance test (OGTT), in identifying participants at increased cardiometabolic risk, in an urban Chinese population.

METHODS

All participants from the fourth visit of the population-based Hong Kong Cardiovascular Risk Factors Prevalence Study, without known diabetes, were included. All had their glycaemic status assessed by OGTT and HbA1c , according to American Diabetic Association 2010 criteria.

RESULTS

Based on OGTT criteria alone, 3.5% of the study cohort (N = 1300) had diabetes and 19.2% had prediabetes. Based on HbA1c criteria only, 6.2% had diabetes and 61.2% had prediabetes. The measurement of HbA1c , in addition to the OGTT, increased the proportion of participants with diabetes to 7.8% and with prediabetes to 65.3%. Subjects with prediabetes having raised HbA1c but normal glycaemia (N = 600) had waist circumference, systolic blood pressure, fasting glucose, insulin resistance index (HOMA-IR), Gutt Index and Framingham 10-year cardiovascular risk scores intermediate between those with both normal HbA1c and glycaemia (N = 350), and those with impaired fasting glucose and/or impaired glucose tolerance (N = 249; all P < 0.01).

CONCLUSION

The measurement of HbA1c in our population, in addition to the OGTT, results in the detection of a large number of participants with prediabetes having raised HbA1c but normal glycaemia who have a cardiometabolic risk profile intermediate between impaired fasting glucose and/or impaired glucose tolerance and normal participants, and would benefit from early lifestyle intervention.

Screening for dysglycaemia by oral glucose tolerance test should be recommended in all women with polycystic ovary syndrome

STUDY QUESTION

Should fasting glucose (FG) or an oral glucose tolerance test (OGTT) be used to screen for dysglycaemia in women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

A full OGTT should be recommended as the screening method for dysglycaemia in women with PCOS, regardless of BMI or family history of diabetes mellitus (DM).

STUDY DESIGN, SIZE, DURATION

A cross-sectional study on 467 Chinese women diagnosed with PCOS by the Rotterdam criteria between January 2010 to December 2013.

PARTICIPANTS, SETTING, METHODS

The study was done at a university hospital in Hong Kong. All subjects underwent a 75 g OGTT after overnight fasting. We evaluated the performance of FG alone, when compared with the full OGTT, in identifying subjects with dysglycaemia (prediabetes or DM, according to the 2010 diagnostic criteria of the American Diabetes Association).

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 467 subjects, 58 (12.4%) had dysglycaemia, among which 46 (9.8%) had prediabetes and 12 (2.6%) had DM, including 4 with known DM. Of the 46 subjects with prediabetes, 25 (54.3%) had normal FG and of the 8 subjects with screened DM in this study, 1 (12.5%) had normal FG. The sensitivity of FG alone in screening for prediabetes, DM and overall dysglycaemia were 45.7, 87.5 and 48.1%, respectively, i.e. missing 54.3% of prediabetes and 12.5% of DM cases as defined by the OGTT. Among the 54 subjects with screened dysglycaemia, 20 (37.0%) had BMI < 25 kg/m(2) and 35 (64.8%) had no family history of DM.

LIMITATIONS, REASONS FOR CAUTION

We only reported on the biochemical diagnosis of DM based on a single time point. In clinical practice, confirmatory results at another time point is required for definitive diagnosis in asymptomatic subjects.

WIDER IMPLICATIONS OF THE FINDINGS

There is an ongoing debate as to whether FG or an OGTT should be used as a screening method for dysglycaemia in women with PCOS. Some guidelines also recommend glucose screening only in those who are overweight and/or having family history of diabetes (DM). There have been scarce data on this issue in the Chinese population, which the current study aims at addressing.

STUDY FUNDING/COMPETING INTERESTS

The study was supported by a research grant from the Hong Kong Obstetrical and Gynaecological Trust Fund, as well as internal research funding of the Department of Obstetrics and Gynaecology, The University of Hong Kong. All authors have no competing interests.

Optimization of miRNA-seq data preprocessing

The past two decades of microRNA (miRNA) research has solidified the role of these small non-coding RNAs as key regulators of many biological processes and promising biomarkers for disease. The concurrent development in high-throughput profiling technology has further advanced our understanding of the impact of their dysregulation on a global scale. Currently, next-generation sequencing is the platform of choice for the discovery and quantification of miRNAs. Despite this, there is no clear consensus on how the data should be preprocessed before conducting downstream analyses. Often overlooked, data preprocessing is an essential step in data analysis: the presence of unreliable features and noise can affect the conclusions drawn from downstream analyses. Using a spike-in dilution study, we evaluated the effects of several general-purpose aligners (BWA, Bowtie, Bowtie 2 and Novoalign), and normalization methods (counts-per-million, total count scaling, upper quartile scaling, Trimmed Mean of M, DESeq, linear regression, cyclic loess and quantile) with respect to the final miRNA count data distribution, variance, bias and accuracy of differential expression analysis. We make practical recommendations on the optimal preprocessing methods for the extraction and interpretation of miRNA count data from small RNA-sequencing experiments.

High speed prototype quantum key distribution system and long term field trial

Securing information in communication networks is an important challenge in today's world. Quantum Key Distribution (QKD) can provide unique capabilities towards achieving this security, allowing intrusions to be detected and information leakage avoided. We report here a record high bit rate prototype QKD system providing a total of 878 Gbit of secure key data over a 34 day period corresponding to a sustained key rate of around 300 kbit/s. The system was deployed over a standard 45 km link of an installed metropolitan telecommunication fibre network in central Tokyo. The prototype QKD system is compact, robust and automatically stabilised, enabling key distribution during diverse weather conditions. The security analysis includes an efficient protocol, finite key size effects and decoy states, with a quantified key failure probability of ε = 10⁻¹⁰.

Robust global microRNA expression profiling using next-generation sequencing technologies

miRNAs are a class of regulatory molecules involved in a wide range of cellular functions, including growth, development and apoptosis. Given their widespread roles in biological processes, understanding their patterns of expression in normal and diseased states will provide insights into the consequences of aberrant expression. As such, global miRNA expression profiling of human malignancies is gaining popularity in both basic and clinically driven research. However, to date, the majority of such analyses have used microarrays and quantitative real-time PCR. With the introduction of digital count technologies, such as next-generation sequencing (NGS) and the NanoString nCounter System, we have at our disposal many more options. To make effective use of these different platforms, the strengths and pitfalls of several miRNA profiling technologies were assessed, including a microarray platform, NGS technologies and the NanoString nCounter System. Overall, NGS had the greatest detection sensitivity, largest dynamic range of detection and highest accuracy in differential expression analysis when compared with gold-standard quantitative real-time PCR. Its technical reproducibility was high, with intrasample correlations of at least 0.95 in all cases. Furthermore, miRNA analysis of formalin-fixed, paraffin-embedded (FFPE) tissue was also evaluated. Expression profiles between paired frozen and FFPE samples were similar, with Spearman's ρ>0.93. These results show the superior sensitivity, accuracy and robustness of NGS for the comprehensive profiling of miRNAs in both frozen and FFPE tissues.

Use of Sequenom sample ID Plus® SNP genotyping in identification of FFPE tumor samples

Short tandem repeat (STR) analysis, such as the AmpFlSTR® Identifiler® Plus kit, is a standard, PCR-based human genotyping method used in the field of forensics. Misidentification of cell line and tissue DNA can be costly if not detected early; therefore it is necessary to have quality control measures such as STR profiling in place. A major issue in large-scale research studies involving archival formalin-fixed paraffin embedded (FFPE) tissues is that varying levels of DNA degradation can result in failure to correctly identify samples using STR genotyping. PCR amplification of STRs of several hundred base pairs is not always possible when DNA is degraded. The Sample ID Plus® panel from Sequenom allows for human DNA identification and authentication using SNP genotyping. In comparison to lengthy STR amplicons, this multiplexing PCR assay requires amplification of only 76-139 base pairs, and utilizes 47 SNPs to discriminate between individual samples. In this study, we evaluated both STR and SNP genotyping methods of sample identification, with a focus on paired FFPE tumor/normal DNA samples intended for next-generation sequencing (NGS). The ability to successfully validate the identity of FFPE samples can enable cost savings by reducing rework.

Lathosterolosis: a disorder of cholesterol biosynthesis resembling smith-lemli-opitz syndrome

Lathosterolosis is an inborn error of cholesterol biosynthesis due to deficiency of the enzyme 3-beta-hydroxysteroid-delta-5-desaturase (or sterol-C5-desaturase or SC5D). This leads to a block in conversion of lathosterol into 7-dehydrocholesterol. Only three patients with lathosterolosis have been reported in literature, of which one survived. We report a patient with dysmorphism, multiple congenital anomalies, and developmental delay, initially suspected to have Smith-Lemli-Opitz syndrome, who was later found to have elevated levels of lathosterol in both plasma and fibroblasts. Genetic study confirmed a compound heterozygous mutation in the sterol-C5-desaturase-like (SC5DL) gene on chromosome 11q23. Simvastatin was started as a treatment therapy and it resulted in normalization of blood lathosterol level and improvement in the neurodevelopmental profile. However, additional patients are needed for better delineation of the clinical spectrum, genotype-phenotype correlation, and potential efficacy of simvastatin treatment in this rare disorder. If the presence of distinctive facial features and limb anomalies raise the suspicion of a cholesterol biosynthesis defect, testing of full sterol profile is warranted as normal cholesterol or 7-dehydrocholesterol levels cannot rule out the diagnosis of cholesterol synthesis defect like lathosterolosis.

Reliability and validity of the overactive bladder symptom score in Hong Kong Chinese

OBJECTIVE

To validate the Hong Kong Chinese translation of the Overactive Bladder Symptom Score questionnaire (OABSS-HKC).

DESIGN

Cross-sectional study.

SETTING

Five urology clinics of different regional hospitals in Hong Kong.

PARTICIPANTS

The Overactive Bladder Symptom Score questionnaire was translated and culturally adapted for Hong Kong Chinese, according to the Principles of Good Practice for the Translation and Cultural Adaptation Process for Patient-Reported Outcomes Measures. Chinese-speaking patients with overactive bladder symptoms were recruited from five urology clinics. The patients completed the OABSS-HKC, a 3-day micturition diary, International Prostate Symptom Scores, and the Patient Perception of Bladder Condition questionnaires (visit 1), and again after a 2-week interval (visit 2). Test-retest reliability was evaluated by the intraclass correlation coefficient and weighted Kappa coefficient. The relationship between OABSS-HKC total scores and items in the comparison measures was evaluated using Spearman's correlation coefficients.

RESULTS

The OABSS-HKC was successfully translated and culturally adapted. Fifty-one patients completed the validation study. A high level of reliability was observed between the OABSS-HKC total score answered at visit 1 and 2 for all subjects (intraclass correlation coefficient, 0.82) and among the four items answered (weighted Kappa coefficients, 0.57-0.75). The OABSS-HKC total score correlated significantly with numbers of micturitions, incontinence and urgency episodes recorded in the 3-day micturition diary, as well as the total International Prostate Symptom Scores and the Patient Perception of Bladder Condition score. However, the OABSS-HKC total score was not significantly associated with nocturia episodes, total voided volume, or number of pads used.

CONCLUSIONS

The OABSS-HKC total scores are reliable and moderately valid for the quantitative evaluation of overactive bladder symptoms in Hong Kong Chinese-speaking adults.

Abstract 5276: Normalization of miRNA-sequencing data

microRNAs (miRNA) are endogenous, small non-coding nucleotides that negatively regulate gene expression post-transcriptionally. Through interactions with Argonaute (Ago) proteins, they form the RNA-induced silencing complex (RISC) and can recognize and bind to the 3’UTR of mRNAs in a sequence-specific manner, leading to translational inhibition or mRNA degradation. Over 30% of human protein-coding genes are predicted to be conserved targets of miRNAs. Consequently, changes in their expression are likely to be associated with the development and progression of diseases, including cancer.

An increasing number of studies are utilizing high-throughput sequencing over microarrays for the expression profiling of miRNAs. Processing of the raw sequencing data usually involves filtering based on quality measures, trimming for adapters and mapping the reads to a (genome or miRNA) reference. Then, normalization of the data is crucial before any downstream analysis can be performed. Normalization is the process of removing sources of variation, which are of non-biological origins (stemming from sample handling, library preparation, imaging and so on), and can affect the measured expression levels. An effective normalization method should minimize technical and experimental bias without introducing noise; the differences that remain should be truly biological effects.

Several normalization methods for miRNA-seq data have been proposed, including linear scaling, non-linear scaling, quantile normalization and variance stabilization normalization. These methods differ in terms of complexity and the assumptions made. However, no standard technique has been recommended. Read counts from each experiment are usually simply adjusted for differences in sequencing depth (library size) to reads-per-million (RPM). Unfortunately, the performance and appropriateness of any of the normalization methods cannot be assessed using real data because the true values are not known.

To this end, we have used a 12x12 Latin Square design to spike in 12 different oligonucleotides with known nominal concentrations, into a complex mixture of human miRNAs. These spike-in pools were subjected to all the preparatory steps of small RNA library construction for sequencing on the Illumina HiSeq2000. Preliminary results show that the spike-in sequences can be recovered successfully from the data. Using this data set, the relative merits of different normalization procedures are being assessed based on measures of bias, variance and improved sensitivity and specificity for the detection of differentially expressed miRNAs. The goal is to identify an optimal normalization method for miRNA-seq data, which would reduce variance without increasing bias.

Citation Format: Shirley Tam, Richard de Borja, Ming-Sound Tsao, John D. McPherson. Normalization of miRNA-sequencing data. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5276. doi:10.1158/1538-7445.AM2013-5276

Prevalence and extent of subclinical atherosclerosis in patients with psoriasis

OBJECTIVE

Patients with psoriasis are prone to premature atherosclerosis and increased risk of cardiovascular disease events. However, the prevalence and extent of atherosclerosis in patients with psoriasis are unknown.

DESIGN

A cross-sectional study.

SETTING AND SUBJECTS

The prevalence and extent of coronary and carotid atherosclerosis were compared in 70 patients with psoriasis (46 ± 9 years, 71% male) without known cardiovascular disease or joint involvement and 51 age- and gender-matched healthy control subjects (45 ± 7 years, 71% male). Systemic inflammation was assessed by the level of high-sensitivity C-reactive protein (hs-CRP). Coronary atherosclerosis was determined by the coronary calcification score (CCS) measured by multi-detector computed tomography. Carotid atherosclerosis was assessed by high-resolution ultrasound-derived carotid intima-media thickness (cIMT).

RESULTS

Patients with psoriasis had a higher prevalence of coronary atherosclerosis (CCS > 0; 28.6% vs. 3.9%, P < 0.01), and a higher degree of coronary atherosclerosis estimated by the mean CCS (67.4 ± 349.2 vs. 0.5 ± 3.0, P < 0.05) compared with controls. Similarly, cIMT was significantly greater in patients with psoriasis than in control subjects (0.73 ± 0.11 mm vs. 0.67 ± 0.08 mm, P < 0.01). Multiple logistic regression revealed that psoriasis [odd ratio (OR): 10.54, 95% confidence interval (CI) 1.89-58.67, P < 0.01] and serum total cholesterol level (OR 2.10, 95% CI 1.01-4.37) were associated with the presence of coronary atherosclerosis (CCS > 0). By contrast, only age was independently associated with increased cIMT. Amongst participants with no traditional cardiovascular disease risk factors, hs-CRP level was higher in patients with psoriasis than in controls.

CONCLUSION

The present results demonstrate early-onset, diffuse arterial atherosclerosis in coronary and carotid arteries in patients with psoriasis, but not in age- and gender-matched control subjects. Low-grade inflammation could explain the presence of premature atherosclerosis in patients with psoriasis.

Increased dietary fruit intake was associated with lower burden of carotid atherosclerosis in Chinese patients with Type 2 diabetes mellitus

BACKGROUND

Previous studies demonstrated that high fruit consumption was associated with a lower risk of cardiovascular events in patients with Type 2 diabetes mellitus. However, the relationship between fruit intake and carotid atherosclerosis in these patients is unknown. We studied the relationship between dietary fruit intake and carotid intima-media thickness in patients with Type 2 diabetes.

METHODS

A total of 255 Chinese patients with Type 2 diabetes were recruited. Dietary fruit intake was assessed by a validated food-frequency questionnaire, and carotid intima-media thickness was measured by high-resolution ultrasonography.

RESULTS

Among patients with three different tertiles of fruit intake (14.5 ± 8.6 vs. 41.5 ± 7.1 vs. 92.6 ± 39.7 g/day), there was no difference in their clinical characteristics (all P > 0.05). Patients with the highest tertile of fruit intake had a significantly higher BMI and diastolic blood pressure than those with the lowest tertile intake. Furthermore, serum high-sensitivity C-reactive protein, 8-isoprostane and superoxide dismutase were similar among the three tertiles of patients (all P > 0.05). However, patients with the highest tertile of fruit intake had lower carotid intima-media thickness (0.97 ± 0.02 vs. 1.08 ± 0.03 mm, P = 0.046) and prevalence of carotid plaque (11.76 vs. 1.18%, P = 0.022) than those with the lowest tertile of fruit intake. Multivariate regression analysis revealed the highest tertile of fruit intake (β = -0.086, P = 0.049) was independently associated with carotid intima-media thickness.

CONCLUSIONS

Our results demonstrated that, in Chinese patients with Type 2 diabetes, higher dietary fruit intake was associated with a lower burden of carotid atherosclerosis as reflected by lower carotid intima-media thickness and prevalence of carotid plaque.

Prospective observational study of isoflavone and the risk of stroke recurrence: potential clinical implications beyond vascular function

BACKGROUND

Whether isoflavone has any effect on recurrent cardiovascular events is unknown.

OBJECTIVE

To investigate the relations between isoflavone intake and the risk of stroke recurrence.

SUBJECTS AND METHODS

We recruited 127 consecutive patients with prior history of atherothrombotic/ hemorrhagic stroke (mean age: 67 ± 11 years, 69% male) and prospectively followed up for a mean duration of 30 months. Stroke recurrence and major adverse cardiovascular events (MACE) were documented. Brachial flow-mediated dilatation (FMD) was measured using high-resolution ultrasound. Isoflavone intake was estimated using a validated food frequency questionnaire.

RESULTS

Median isoflavone intake was 6.9 (range: 2.1 - 14.5) mg/day. Isoflavone intake was independently associated with increased FMD (Pearson R=0.23, p=0.012). At 30 months, there were 10 stroke recurrence and 12 MACE. Kaplan-Meier analysis showed that patients with isoflavone intake higher than median value had significantly longer median stroke recurrence-free survival time (19.0 [range: 10.4 - 27.6] mth versus 5.0 [range: 4.1 - 5.9] mth, p=0.021) and MACE-free survival time (19.0 [range: 10.4 - 27.6] mth versus 4.0 [range: 2.4 - 5.6] mth, p=0.013). Using multivariate cox regression, higher isoflavone intake was an independent predictor for lower risk of stroke recurrence (hazards ratio 0.18 [95%CI: 0.03 - 0.95], risk reduction 82%, p=0.043) and MACE (hazards ratio 0.16 [95%CI: 0.03 - 0.84], risk reduction 84%, p=0.030).

CONCLUSIONS

Higher isoflavone intake in stroke patients was associated with prolonged recurrence-free survival, and reduced risk of stroke recurrence and MACE independent of baseline vascular function. Whether isoflavone may confer clinically significant secondary protection in stroke patients should be further investigated in a randomized controlled trial.

Adverse systemic arterial function in patients with selenium deficiency

BACKGROUND

Experimental studies have shown that selenium is involved in the synthesis of selenoproteins which might contribute to cardiovascular protection. However, the relationship between selenium deficiency and vascular function in clinical context remains unknown.

OBJECTIVE

To investigate for any relationship between selenium deficiency and systemic arterial function in patients with high risk of vascular events.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

306 consecutive patients with high risk for cardiovascular events (coronary artery disease 35%, acute/ recurrent ischemic stroke 40%, diabetes mellitus 54%) followed up at internal medicine outpatient clinics.

MEASUREMENTS

Non-invasive brachial-ankle pulse wave velocity (PWV) was determined using vascular profiling system (VP-2000). Long-term intake of selenium was determined by a validated food frequency questionnaire.

RESULTS

Mean daily selenium intake was 59.5 ± 52.1 mcg/day, and mean PWV was 1782.4 ± 418.4 cm/s. Patients with selenium intake <10th percentile had significantly higher PWV as compared to patients with intake ≥ 10th percentile (1968.2 ± 648.9 cm/s versus 1762.2 ± 381.6 cm/s, P=0.010). After adjusting for potential confounders including age, gender, history of hypertension, hyperlipidemia, diabetes and cardiovascular disease, smoking status, use of cardiovascular medications, waist-hip ratio, education/ financial status, physical activity, calorie intake and intake of antioxidant vitamins, deficient selenium intake <10th percentile remained independently predictive of increased PWV by +363.4 cm/s [95% CI: 68.1 to 658.6, P=0.016, relative increase 21%].

CONCLUSIONS

Selenium deficiency is associated with adverse arterial function in patients with high risk for vascular events.

Increased arterial stiffness in patients with psoriasis is associated with active systemic inflammation

BACKGROUND

Psoriasis is associated with premature atherosclerosis although the underlying mechanism remains unclear.

OBJECTIVES

We sought to investigate the relationship between disease activity and systemic inflammation in patients with psoriasis, and macrovascular and microvascular function.

METHODS

Fifty-two patients with psoriasis (mean ± SD age 44 ± 8 years; 38 men) were compared with 50 age- and sex-matched controls. Baseline demographics and high-sensitivity C-reactive protein (hs-CRP) level were recorded for each subject. Psoriatic disease activity was assessed using the Psoriasis Area and Severity Index (PASI). Arterial stiffness and endothelial function were assessed using brachial to ankle pulse wave velocity (baPWV) and digital hyperaemic response measured using the peripheral arterial tonometry (PAT) index.

RESULTS

Patients with psoriasis had significantly higher hs-CRP (mean ± SD 5·3 ± 5·1 vs. 1·9 ± 1·6 mg L(-1), P < 0·01) and baPWV (mean ± SD 14·5 ± 2·5 vs. 13·2 ± 1·6 m s(-1) , P < 0·01) but not PAT index (mean ± SD 2·06 ± 0·59 vs. 2·10 ± 0·44, P = 0·70) than controls. There was significant correlation of hs-CRP with baPWV (r = 0·51, P < 0·01) and with PASI (r = 0·48, P < 0·01). Multiple linear regression analysis demonstrated that baPWV is independently correlated with age, fasting glucose and hs-CRP (P < 0·05), but does not predict PAT index. Each mg L(-1) increase in hs-CRP accounted for an increase in baPWV of +0·12 m s(-1) (95% confidence interval 0·01-0·22, P = 0·03).

CONCLUSIONS

Young patients with psoriasis have increased arterial stiffness but not microvascular dysfunction compared with healthy controls. More importantly, hs-CRP positively correlated with, and independently predicted, arterial stiffness. This suggests that systemic inflammation in patients with psoriasis is associated with premature atherosclerosis.

Biochemical and molecular characterization of tyrosine hydroxylase deficiency in Hong Kong Chinese

Tyrosine hydroxylase deficiency is a rare neurotransmitter disorder affecting the rate-limiting step in catecholamine biosynthesis. There are about 40 cases reported worldwide. Here, we report the biochemical and molecular findings of eight unrelated Chinese patients with tyrosine hydroxylase deficiency. We have identified eight novel mutations with 5 missense, 2 nonsense and 1 splicing mutations in the TH gene, namely p.R153X, p.R169X, p.G294R, p.G315S, p.A385V, p.I394T, p.G408R, and c.1163+5G>C. The mutations of the TH gene in Chinese are heterogeneous.

Fish-oil supplement has neutral effects on vascular and metabolic function but improves renal function in patients with Type 2 diabetes mellitus

AIMS

Increased dietary fish-oil consumption is associated with a reduced risk of coronary heart events and has pronounced effects on dyslipidaemia. However, the effects of fish-oil supplement on vascular function and metabolic profile in patients with Type 2 diabetes mellitus (DM) are unclear.

METHODS

In a double-blind placebo-controlled trial, we randomized 97 Type 2 DM patients without prior cardiovascular disease to fish-oil (4 g/day, n = 49) or olive-oil (with equivalent calories, as placebo, n = 48) supplements for 12 weeks. Assessment of vascular function with brachial artery flow-mediated dilation (FMD) and circulating levels of endothelial progenitor cells (EPCs), and metabolic parameters, high-sensitivity C-reactive protein (hsCRP), oxidative stress markers and renal function were examined before and after the supplement.

RESULTS

Despite a significant reduction in serum triglycerides (-0.47 mmol/l, P < 0.01), 12-week supplement of fish oil did not improve vascular function as determined by FMD (+0.16%, P = 0.83) and circulating EPC count (+4 cells/microl, P = 0.78). Furthermore, fish-oil supplement did not have any significant treatment effects on hsCRP, oxidative stress, low- and high-density lipoprotein and glycated haemoglobin (HbA(1c)) (all P > 0.05). In contrast, serum creatinine was lower (-4.5 micromol/l, P = 0.01) in fish-oil-treated patients as compared with control subjects.

CONCLUSIONS

This study demonstrated that 12 weeks of fish-oil supplement had no significant beneficial effect on vascular endothelial function, but improved renal function without changes in endothelial function, metabolic profiles, blood pressure, inflammation or oxidative stress in patients with Type 2 DM.

A randomised controlled trial of nasal continuous positive airway pressure on insulin sensitivity in obstructive sleep apnoea

The effects of treatment of obstructive sleep apnoea (OSA) on glucose metabolism have been investigated previously with conflicting results. This study evaluated the impact of nasal continuous positive airway pressure (nCPAP) treatment of OSA on insulin sensitivity. Males with moderate/severe OSA and no significant comorbidity were randomised to a therapeutic or sham nCPAP treatment group for 1 week and then reassessed. Those who received therapeutic nCPAP were further evaluated at 12 weeks. Insulin sensitivity (K(itt)) was estimated by the short insulin tolerance test. Other evaluations included blood pressure, metabolic profile, urinary catecholamines and intra-abdominal fat. In total, 61 Chinese subjects were randomised. 31 subjects receiving therapeutic nCPAP showed an increase in K(itt) (6.6+/-2.9 to 7.6+/-3.2 % x min(-1); p = 0.017), while the 30 patients on sham CPAP had no significant change, and the changes in K(itt) were different between the two groups (p = 0.022). At 12 weeks, improvement in K(itt) was seen in 20 subjects with BMI >or=25 kg x m(-2) (median (interquartile range) 28.3 (26.6-31.5); p = 0.044), but not in the nine subjects with BMI<25 kg x m(-2), or the entire group. The findings indicate that therapeutic nCPAP treatment of OSA for 1 week improved insulin sensitivity in nondiabetic males, and the improvement appeared to be maintained after 12 weeks of treatment in those with moderate obesity.

Iron supplement in pregnancy and development of gestational diabetes--a randomised placebo-controlled trial

OBJECTIVE

To test the hypothesis that iron supplement from early pregnancy would increase the risk of gestational diabetes mellitus (GDM).

DESIGN

Randomised placebo-controlled trial.

SETTING

A university teaching hospital in Hong Kong.

POPULATION

One thousand one hundred sixty-four women with singleton pregnancy at less than 16 weeks of gestation with haemoglobin (Hb) level between 8 and 14 g/dl and no pre-existing diabetes or haemoglobinopathies.

METHODS

Women were randomly allocated to receive 60 mg of iron supplement daily (n= 565) or placebo (n= 599). Oral glucose tolerance tests (OGTTs) were performed at 28 and 36 weeks. Women were followed up until delivery.

OUTCOME MEASURES

The primary outcome was development of GDM at 28 weeks. The secondary outcomes were 2-hour post-OGTT glucose levels, development of GDM at 36 weeks and delivery and infant outcomes.

RESULTS

There was no significant difference in the incidence of GDM in the iron supplement and placebo groups at 28 weeks (OR: 1.04, 95% confidence interval [CI]: 0.7-1.53 at 90% power) or 36 weeks. Maternal Hb and ferritin levels were higher in the iron supplement group at delivery (P < 0.001 and P= 0.003, respectively). Elective caesarean section rate was lower in the iron supplement group (OR: 0.58, 95% CI: 0.37-0.89). Infant birthweight was heavier (P= 0.001), and there were fewer small-for-gestational-age babies in the iron supplement group (OR: 0.46, 95% CI: 0.24-0.85).

CONCLUSION

Iron supplement from early pregnancy does not increase the risk of GDM. It may have benefits in terms of pregnancy outcomes.

Prodrug delivery of novel PTP1B inhibitors to enhance insulin signalling

A growing percentage of the population is resistant to two key hormones - insulin and leptin - as a result of increased obesity, often leading to significant health consequences such as type 2 diabetes. Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of signalling by both of these hormones, so that inhibitors of this enzyme may provide promise for correcting endocrine abnormalities in both diabetes and obesity. As with other tyrosine phosphatases, identification of viable drug candidates targeting PTP1B has been elusive because of the nature of its active site. Beginning with novel phosphotyrosine mimetics, we have designed some of the most potent PTP1B inhibitors. However, their highly acidic structures limit intrinsic permeability and pharmacokinetics. Ester prodrugs of these inhibitors improve their drug-like properties with the goal of delivering these nanomolar inhibitors to the cytoplasm of cells within target tissues. In addition to identifying prodrugs that is able to deliver active drugs into cells to inhibit PTP1B and increase insulin signalling, these compounds were further modified to gain a variety of cleavage properties for targeting activity in vivo. One such prodrug candidate improved insulin sensitivity in ob/ob mice, with lowered fasting blood glucose levels seen in the context of lowered fasting insulin levels following 4 days of intraperitoneal dosing. The results presented in this study highlight the potential for design of orally active drug candidates targeting PTP1B, while also delineating the considerable challenges remaining.

Organ-specific hemosiderosis and functional correlation in Chinese patients with thalassemia intermedia and hemoglobin H disease

We performed MRI assessment in 37 adult Chinese patients with thalassemia intermedia and hemoglobin H disease. Despite abnormal ferritin and liver T2*, only 5% of patients had cardiac hemosiderosis. The two patients with reduced ejection fraction had normal cardiac T2*. Half of the cases showed pituitary and pancreatic iron loading. Subclinical endocrine abnormalities (HOMA, insulin growth factor) showed correlation with pancreatic, pituitary, and cardiac MRI values. Prospective data with serial functional and imaging monitoring is needed to verify the utility for chelation to improve cardiac and endocrine function in this group of patients.

One-stop measurement of iron deposition in the anterior pituitary, liver, and heart in thalassemia patients

PURPOSE

To assess the feasibility of one-stop evaluation of iron load of myocardium, liver, and anterior pituitary gland in thalassemia patients.

MATERIALS AND METHODS

Fifty thalassemia major patients underwent a breath-hold magnetic resonance imaging (MRI) sequence for assessment of T2* for liver and myocardium, a short axis cine trueFISP sequence covering base to apex to assess the ejection fraction of left ventricle, and a turbo spin echo T2-weighted sequence for the anterior pituitary gland. The MRI parameters were correlated with serum growth hormone, insulin growth factor-1 (IGF-1), insulin growth factor binding protein-3 (IGFBP-3), and endocrine failure.

RESULTS

Ferritin was found to be associated with T2* liver (P < 0.005), T2SI (signal intensity) pituitary (P = 0.001), and T2 pituitary/fat (P = 0.001), but not with T2* heart. There was significant correlation of T2SI pituitary with IGF-1 and IGFBP-3. T2* liver (P < 0.001), T2* heart (P < 0.001), pituitary SI (P < 0.001) and pituitary/fat SI (P = 0.002) were also found to be significantly correlated with a history of hypogonadism. T2* heart was also found to be significantly correlated with IGF-1.

CONCLUSION

A quick MRI protocol for assessment of T2* liver, T2* heart, and T2SI pituitary is technically feasible. This might form an objective basis to monitor the response to different organs to chelation therapy.

Rapamycin prevents the development of nephritis in lupus-prone NZB/W F1 mice

Rapamycin is a potent immunosuppressive drug currently used mainly for rejection prophylaxis in renal transplantation. The aim of this study was to determine the effect of rapamycin treatment on the development of nephritis in lupus-prone New Zealand Black/White F1 (NZB/W F1) mice. Twelve-week-old female NZB/W F1 mice were treated with rapamycin (3 mg/kg body weight) or saline once daily by oral gavage for 20 weeks. The severity of nephritis was assessed by clinical and biochemical parameters, renal histology, immunohistochemistry and gene expression studies. Rapamycin treatment markedly reduced proteinuria, improved renal function, decreased serum anti-double stranded DNA antibody levels and diminished splenomegaly. Kidney sections from saline-treated mice showed marked mesangial proliferation, tubular dilation with protein cast deposition and interstitial inflammatory cell infiltration. Rapamycin-treated mice had near normal renal histology, with marked reduction in glomerular immune deposition and the infiltration by T cells, B cells and macrophages. Rapamycin treatment was associated with down-regulation of intra-renal expression of monocyte chemoattractant protein-1 (MCP-1) mRNA and protein. We conclude that rapamycin is highly effective in preventing the development of nephritis in NZB/W F1 mice. The beneficial effects of rapamycin are mediated through inhibition of lymphoproliferation and reduced MCP-1 expression.