Loss of p53-DREAM-mediated repression of cell cycle genes as a driver of lymph node metastasis in head and neck cancer

BACKGROUND

The prognosis for patients with head and neck cancer (HNC) is poor and has improved little in recent decades, partially due to lack of therapeutic options. To identify effective therapeutic targets, we sought to identify molecular pathways that drive metastasis and HNC progression, through large-scale systematic analyses of transcriptomic data.

METHODS

We performed meta-analysis across 29 gene expression studies including 2074 primary HNC biopsies to identify genes and transcriptional pathways associated with survival and lymph node metastasis (LNM). To understand the biological roles of these genes in HNC, we identified their associated cancer pathways, as well as the cell types that express them within HNC tumor microenvironments, by integrating single-cell RNA-seq and bulk RNA-seq from sorted cell populations.

RESULTS

Patient survival-associated genes were heterogenous and included drivers of diverse tumor biological processes: these included tumor-intrinsic processes such as epithelial dedifferentiation and epithelial to mesenchymal transition, as well as tumor microenvironmental factors such as T cell-mediated immunity and cancer-associated fibroblast activity. Unexpectedly, LNM-associated genes were almost universally associated with epithelial dedifferentiation within malignant cells. Genes negatively associated with LNM consisted of regulators of squamous epithelial differentiation that are expressed within well-differentiated malignant cells, while those positively associated with LNM represented cell cycle regulators that are normally repressed by the p53-DREAM pathway. These pro-LNM genes are overexpressed in proliferating malignant cells of TP53 mutated and HPV + ve HNCs and are strongly associated with stemness, suggesting that they represent markers of pre-metastatic cancer stem-like cells. LNM-associated genes are deregulated in high-grade oral precancerous lesions, and deregulated further in primary HNCs with advancing tumor grade and deregulated further still in lymph node metastases.

CONCLUSIONS

In HNC, patient survival is affected by multiple biological processes and is strongly influenced by the tumor immune and stromal microenvironments. In contrast, LNM appears to be driven primarily by malignant cell plasticity, characterized by epithelial dedifferentiation coupled with EMT-independent proliferation and stemness. Our findings postulate that LNM is initially caused by loss of p53-DREAM-mediated repression of cell cycle genes during early tumorigenesis.

7-UP: Generating in silico CODEX from a small set of immunofluorescence markers

Multiplex immunofluorescence (mIF) assays multiple protein biomarkers on a single tissue section. Recently, high-plex CODEX (co-detection by indexing) systems enable simultaneous imaging of 40+ protein biomarkers, unlocking more detailed molecular phenotyping, leading to richer insights into cellular interactions and disease. However, high-plex data can be slower and more costly to collect, limiting its applications, especially in clinical settings. We propose a machine learning framework, 7-UP, that can computationally generate in silico 40-plex CODEX at single-cell resolution from a standard 7-plex mIF panel by leveraging cellular morphology. We demonstrate the usefulness of the imputed biomarkers in accurately classifying cell types and predicting patient survival outcomes. Furthermore, 7-UP's imputations generalize well across samples from different clinical sites and cancer types. 7-UP opens the possibility of in silico CODEX, making insights from high-plex mIF more widely available.

Splenogonadal fusion: aiding detection and avoiding radical orchidectomy

Splenogonadal fusion is a rare benign congenital anomaly in which there is an abnormal connection between the gonad and the spleen. It was first described over 100 years ago with limited reports in the literature since then. Its similarity in presentation to testicular neoplasia poses a significant challenge in diagnosis and management, often resulting in radical orchidectomy. We present the case of a 31-year-old man who presented with a rapidly growing left-sided testicular mass and suspicious ultrasound findings; histology from the subsequent radical inguinal orchidectomy showed findings consistent with splenogonadal fusion. We describe points for consideration in the clinical history, examination and imaging that could suggest splenogonadal fusion, including preoperative technetium-99m-sulfur colloid imaging and intraoperative frozen section evaluation, which may confirm the diagnosis and prevent unnecessary orchidectomy.

20 Tumor-informed liquid biopsy monitoring of evolving therapeutic resistance mechanisms in head and neck squamous cell carcinoma patients receiving anti-PD-1 therapy

Background

Typical liquid biopsy panels offer a limited understanding of tumor biology, potentially under-representing the heterogeneity of resistance in late-stage cancers. Here, diminished scope can result in undetected, therapeutically-relevant biomarkers which respond dynamically to treatment, as well as potentially missed resistance mechanisms and pathway-level events. To address the challenges associated with identifying multiple concurrent heterogeneous resistance mechanisms in individual patients, we evaluated longitudinal exome-scale tumor-informed cell-free DNA (cfDNA) data from head and neck squamous cell carcinoma (HNSCC) patients receiving anti-PD1 therapy.

Methods

Pre- and post-intervention matched tumor, normal and plasma samples were retrospectively obtained from 15 stage II-IV HNSCC patients. Following baseline sample collection, all patients received a single dose of nivolumab or pembrolizumab. The primary tumor was then resected approximately one month later when possible, or a second biopsy collected where resection was impractical. Paired tumor and normal samples were then profiled using ImmunoID NeXT Platform®, an augmented exome/transcriptome platform and analysis pipeline. Exome-scale cfDNA profiling of matched plasma samples was performed using the NeXT Liquid BiopsyTM platform to detect somatic variants.

Results

Patient neoantigen presentation score (NEOPSTM) rapidly and significantly contracted following therapy (p=.00098). Novel neoantigens arising post-treatment which were predicted to be presented on lost HLA alleles were significantly higher in patients with longer overall survival (p=.019). Variant detection across same-patient serial cfDNA samples revealed significantly correlated VAFs (R=.62, p<.0001) despite significant contraction of mutational burden in solid tumor (p=.0039), suggesting complex clonal/subclonal dynamics. Investigation of the evolving tumor and cfDNA subclonal architecture revealed significant association between decreasing cellular prevalence and NOTCH signaling (q=.001) and the innate immune system (q=.002), while increasing cellular prevalence was associated with p53 signalling (q=.02) and hypoxia (q=.02). These findings were complimented by transcriptomic data which showed significant enrichment of multiple immune pathways across treatment.

Conclusions

We found that immune checkpoint blockade precipitates rapid evolution of the HNSCC tumor microenvironment. By leveraging comprehensive, tumor-informed liquid biopsy data we were able to identify contracting cellular populations enriched for NOTCH pathway mutations. Longer OS following either intervention was associated with an expansion of novel neoantigens predicted to be presented by lost HLA alleles. Our results suggest that tumor-informed liquid biopsy provides a more robust understanding of therapeutic response and resistance mechanisms than that attainable with typical liquid biopsy panels alone.

Ethics Approval

This study obtained ethics approval from Human Subjects Research at Stanford University. ID number is 40425. All participants gave informed consent prior to enrollment.

Abstract 399: Pan-cancer survey of HLA loss of heterozygosity using a robustly validated NGS-based machine learning algorithm

HLA loss of heterozygosity (LOH) is increasingly being recognized as an important immune escape mechanism in response to checkpoint inhibitor therapy. HLA LOH reduces the repertoire of neoantigens displayed on the cell surface of cancer cells, limiting the efficacy of the immune system to detect and eliminate them. Though highly accurate HLA LOH detection algorithms are needed to allow clinical utility, the field lacks robust, allele-specific validation approaches. Moreover, algorithms of unknown sensitivity and specificity have led to significant discrepancies in the estimated occurrence of HLA LOH as an immune escape mechanism across tumor types. To address these challenges, we have developed a machine learning algorithm to detect HLA LOH (DASH - Deletion of Allele-Specific HLAs), established the accuracy of the algorithm with an allele-specific PCR validation strategy, investigated the frequencies of HLA LOH across 14 tumor types in a cohort of over 800 patients and observed allele-specific neoantigen expansion in response to immunotherapy. To build DASH, we profiled 279 patients on the ImmunoID NeXT Platform to create a training dataset. Our novel features, which account for allele-specific differences in exome probe capture and capitalize on our whole exome platform by including information about copy number alterations in the regions flanking the HLA genes, were used to train an XGBoost model. Orthogonal, allele-specific validation was required to accurately assess sensitivity and specificity for clinical utility. Thus, we profiled over 30 paired tumor-normal cell lines on the ImmunoID NeXT Platform® and identified cell lines with HLA LOH. Using in silico mixtures, we found 100% sensitivity and specificity for tumors with at least 36% tumor purity. Next, we designed a digital PCR (dPCR) assay using patient-specific, allele-specific primers that target a single HLA allele while avoiding all other HLA alleles and tested the limit of detection of the assay in the same cell lines. Then, we performed dPCR with patient-specific primers on 20 tumor and normal sample pairs and found 94% sensitivity. After establishing the high sensitivity and specificity of DASH, we profiled over 800 patients spanning 14 tumor types on the ImmunoID NeXT Platform. We found that over 25% of patients in the majority of tumor types had at least one HLA LOH event. Further, we observed that novel neoantigens that arose during checkpoint treatment were significantly more likely to bind to deleted HLA alleles as compared to the remaining HLA alleles in a head and neck carcinoma cohort treated with anti-PD-1 therapy, shedding light on the mechanism of immune escape in response to checkpoint inhibitors. In summary, we introduced an HLA LOH detection method, performed allele-specific validation, exposed widespread HLA across tumor types and observed the mechanism of immune escape in response to immunotherapy.

Citation Format: Rachel Marty Pyke, Datta Mellacheruvu, Charles Abbott, Steven Dea, Eric Levy, Simo V. Zhang, Nikita Bedi, A. Dimitrios Colevas, Devayani Bhave, Manju Chinnappa, Gabor Bartha, John Lyle, John West, Michael Snyder, John Sunwoo, Richard Chen, Sean Michael Boyle. Pan-cancer survey of HLA loss of heterozygosity using a robustly validated NGS-based machine learning algorithm [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 399.

Abstract 555: Longitudinal exome-scale liquid biopsy monitoring of evolving therapeutic resistance mechanisms in head and neck squamous cell carcinoma patients receiving anti-PD-1 therapy

Background Typical liquid biopsy panels capture a relatively small number of variants, and likely under-represent the heterogeneity of resistance in late-stage cancers. This reduced scope can result in overlooked therapeutic biomarkers which respond dynamically to treatment, as well as potentially missed resistance mechanisms and pathway-level events. To address the challenges associated with identifying multiple concurrent heterogeneous resistance mechanisms in individual patients, we evaluated longitudinal whole exome sequencing of cell free DNA (cfDNA) and solid tumor biopsies from head and neck squamous cell carcinoma (HNSCC) patients that received anti-PD1 therapy. Using this approach, we identified evolving variant and pathway-level resistance mechanisms in cfDNA, as a complement to tumor biopsy derived information, and identified differences in putative neoantigens found in tissue and cfDNA.

Methods Pre- and post-intervention matched tumor, normal and plasma samples were obtained from a pilot cohort of 13 patients with HNSCC. Following baseline sample collection, all patients received a single dose of nivolumab. The primary tumor was then resected, approximately one month later when possible, or a second biopsy was collected where resection was impractical. Paired tumor and normal samples were profiled using ImmunoID NeXTTM, an augmented exome/transcriptome platform and analysis pipeline. Exome-scale cfDNA profiling of matched plasma samples was performed using the NeXT Liquid BiopsyTM platform to detect somatic variants. Data from these two platforms were then compared with corresponding clinical findings.

Results We observed a rapid evolution of the tumor microenvironment and disease mutation profile following therapy, with strong concordance detected between plasma and tumor variants at each timepoint. Post-therapy interrogation of cfDNA revealed dynamic changes in numerous oncogenes and clinically relevant pathways, such as ERK1/2 and MAPK, that were not observed in solid tumor. These findings suggest that single-lesion biopsy of the primary tumor misses co-occurring, clinically relevant resistance alterations. Median post-treatment neoantigen count was reduced in solid tumor, but increased in cfDNA. HLA-specific loss of heterozygosity (LOH) was identified in a number of subjects, likely resulting in reduced neoepitope presentation in those cases.

Conclusions Exome-wide somatic events were reliably detected in cfDNA, providing additional potential biomarkers to complement those identified in solid tumor. As we increase our cohort size, we expect that identification of biomarkers from both exome scale tissue biopsy and cfDNA will provide a more comprehensive view into therapeutic response and resistance mechanisms in HNSCC patients missed with typical liquid biopsy panels.

Citation Format: Charles W. Abbott, Nikita Bedi, Simo V. Zhang, Josette Northcott, Robin LI, Rachel Marty Pyke, Eric Levy, Rebecca Chernock, Mena Mansour, A. Dimitrios Colevas, John Lyle, John B. Sunwoo, Sean Boyle, Richard Chen. Longitudinal exome-scale liquid biopsy monitoring of evolving therapeutic resistance mechanisms in head and neck squamous cell carcinoma patients receiving anti-PD-1 therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 555.

Association of HLA loss of heterozygosity with allele-specific neoantigen expansion in response to immunotherapy

e18030

Background: Human leukocyte antigen loss of heterozygosity (HLA LOH) restricts immune recognition of tumors by limiting the major histocompatibility complex (MHC) presentation of neoantigens to T cells and correlates with reduced response to immune checkpoint blockade therapy (ICB) in non-small cell lung cancer. To explore the mechanism behind the impairment of HLA LOH on ICB, we analyzed the relationship between the antigen presentation pathway, neoantigen presentation and response to ICB in a head and neck squamous cell carcinoma (HNSCC) cohort. Methods: Following baseline sample collection, a cohort of 14 HNSCC patients recieved a single dose of PD-1 inhibitor. The primary tumor mass was definitively resected approximately one month later. If resection was impractical, a second biopsy was taken. Response to therapy was evaluated using RECIST criteria. Each pre- and post-intervention tumor sample and normal PBMC sample were profiled using Personalis’ ImmunoID NeXT Platform, an HLA-enhanced exome/transcriptome platform. HLA LOH was detected using a digital PCR validated machine learning algorithm (DASH). Neoantigen presentation was computationally predicted using a machine learning algorithm (SHERPATM) trained on mono-allelic immunopeptidomics data. Results: We found that 50% of the HNSCC cohort had HLA LOH, a larger percentage than in a large pan-cancer cohort (23%, n=611) and a distinct HNSCC cohort (40%, n=20). Further, two patients had B2M LOH and one patient had a deleterious mutation in an HLA allele. Despite the high frequency of somatic alteration in the antigen presentation pathway, we did not find an association between HLA LOH and ICB response. However, if HLA LOH was still shaping tumor evolution in response to ICB, we would expect to see immune pressure against subclonal tumor populations with neoantigens presentable by the retained HLA alleles but not the deleted HLA alleles. Indeed, we found that significantly more novel post-treatment neoantigens were predicted to bind to deleted HLA alleles compared to their homologous alleles (p=0.045). Conclusions: Given the high prevalence of HLA LOH across tumor types, a greater understanding is needed regarding the impact of HLA LOH on tumor evolution during ICB treatment. Though HLA LOH does not correlate with response to ICB, the consistent shift in neoantigen composition suggests that it acts as an evolutionary force in resistance to response during immunotherapy.

Splenogonadal fusion: aiding detection and avoiding radical orchidectomy

Splenogonadal fusion is a rare benign congenital anomaly in which there is an abnormal connection between the gonad and the spleen. It was first described over 100 years ago with limited reports in the literature since then. Its similarity in presentation to testicular neoplasia poses a significant challenge in diagnosis and management, often resulting in radical orchidectomy. We present the case of a 31-year-old man who presented with a rapidly growing left-sided testicular mass and suspicious ultrasound findings; histology from the subsequent radical inguinal orchidectomy showed findings consistent with splenogonadal fusion. We describe points for consideration in the clinical history, examination and imaging that could suggest splenogonadal fusion, including preoperative technetium-99m-sulfur colloid imaging and intraoperative frozen section evaluation, which may confirm the diagnosis and prevent unnecessary orchidectomy.

Abstract 6678: Sensitive HLA loss of heterozygosity detection reveals allele-specific neoantigen expansion as resistance mechanism to anti-PD-1 therapy

Loss of heterozygosity (LOH) in the HLA locus is increasingly being recognized as an important mechanism of immune escape and a proposed biomarker for immunotherapy response. Neoantigens that bind to a deleted HLA allele will no longer be presented to the immune system, potentially allowing subclones with these deletions to escape immune surveillance. Despite interest in the field, few methods exist to detect HLA LOH, and their sensitivity is not well understood. Moreover, the mechanistic impact of HLA LOH in response to immune checkpoint inhibitors (ICI) remains unexplored. Here, using a novel tool to detect HLA LOH, DASH (Deletion of Allele-Specific HLAs), we reveal allele-specific neoantigen expansion in response to ICIs in a head and neck carcinoma cohort and the widespread occurrence of HLA LOH across several tumor types.

We performed exome sequencing with ImmunoID NeXT, which enhances coverage of the HLA locus, on tumor and normal samples from 260 patients to create a training dataset for our model. For each patient, we mapped reads to each of their allele-specific HLAs and manually annotated LOH. Then, using purity, ploidy and two novel features (normalized b-allele frequency and allele-specific coverage ratios), we trained an XGBoost model.

To evaluate our tool, we compared DASH predictions on held out tumor samples to deletion calls from a standard copy number tool in the regions flanking each HLA gene (91% concordance, 0.73 F1-score), ascertained our sensitivity by diluting cell line data with known HLA LOH to imitate variable purity (100% accuracy in samples above 17% purity) and confirmed the functional impact of HLA LOH using immunopeptidomics data of tumor samples (average of 47% fewer unique peptides binding to lost alleles than kept). To explore the mechanistic impact of HLA LOH in response to ICIs, we studied a cohort of nine head and neck carcinoma patients who received a single dose of nivolumab, and sequenced pre- and posttreatment tumor biopsies for each patient. With DASH, we detected HLA LOH in four of the patients, pretreatment. For these patients, we found a significant posttreatment expansion of neoantigens predicted to bind to the deleted HLA alleles in comparison to the pretreatment biopsy (p=0.046, Wilcoxon signed-rank), revealing the evolutionary force of HLA LOH as a resistance mechanism during ICI therapy. To assess the pervasiveness of HLA LOH across tumor types, we applied DASH to over 500 pretreatment tumors across 13 tumor types and found highly variable frequencies of HLA LOH across the tumor types.

In summary, we developed a sensitive method to detect HLA LOH and exposed neoantigen expansion to deleted HLA alleles in response to ICI therapy, emphasizing the limitations of deleted alleles to ignite an immune response. Moreover, we found widespread occurrences of HLA LOH across tumor types, highlighting the importance of accurate HLA LOH detection as a pan-cancer biomarker.

Citation Format: Rachel Marty Pyke, Charles Abbott, Dattatreya Mellacheruvu, Simo V. Zhang, Nikita Bedi, A. Dimitrios Colevas, John Sunwoo, John West, Richard Chen, Sean Michael Boyle. Sensitive HLA loss of heterozygosity detection reveals allele-specific neoantigen expansion as resistance mechanism to anti-PD-1 therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6678.

Exome scale liquid biopsy characterization of putative neoantigens and genomic biomarkers pre- and post anti-PD-1 therapy in squamous cell carcinoma of the head and neck

6557

Background: The reduced scope, and number of genes profiled by typical liquid biopsy panels can result in missed biomarkers including neoantigens, which may change with treatment, as well as potentially undetected resistance mechanisms and pathways beyond the scope of targets typically captured by panels. To address these limitations, we used a whole-exome scale liquid biopsy monitoring platform, NeXT Liquid Biopsy, to analyze head and neck squamous cell carcinoma (HNSCC) patients that have received anti-PD1 therapy. Presently, we sought to (1) monitor neoantigen changes in cfDNA as a complement to tumor biopsy-derived neoantigens, (2) compare the impact of tumor escape mechanisms, including HLA-LOH, on neoantigens identified in tissue and cfDNA and (3) to identify novel biological signatures that combine information from both solid tumor and liquid biopsies. Methods: Pre- and post-intervention matched normal, tumor and plasma samples were collected from a cohort of 12 patients with HNSCC. Following baseline sample collection all patients received a single dose of nivolumab, followed by resection approximately one month later when feasible, or a second biopsy where resection was impractical. Solid tumor and matched normal samples were profiled using ImmunoID NeXT, an augmented exome/transcriptome platform and analysis pipeline. Exome-scale somatic variants were identified in cfDNA from plasma samples using the NeXT Liquid Biopsy platform. Data from these two platforms were compared with corresponding clinical findings. Results: Concordant somatic events were detected between plasma and tumor at pre- and post-treatment timepoints. Neoantigens predicted to arise from these somatic events were reduced in solid tumor post-treatment, but increased in cfDNA, when compared to pre-treatment timepoints. HLA LOH was identified in a number of subjects, likely resulting in reduced neoepitope presentation in those cases. Immune cell infiltration increased in the tumor following treatment, with no changes to the CD8+/Treg cell ratio, suggesting consistent immunoregulation. Conclusions: Exome-wide neoantigen burden was reliably predicted from cfDNA, providing additional insight complementing data from solid tumor. Analyzing HLA LOH, and neoantigen burden from both solid and liquid biopsies together over the course of treatment creates a more comprehensive profile of therapeutic response and resistance mechanisms in HNSCC patients missed with typical liquid biopsy panels.

A Next-Generation Single-Port Robotic Surgical System for Transoral Robotic Surgery: Results From Prospective Nonrandomized Clinical Trials

Importance

Transoral endoscopic head and neck surgery now plays an important role in the multidisciplinary management of oropharyngeal carcinoma. Previous generations of robotic surgical systems used a multiport system with a rigid stereo-endoscope and 2 wristed instruments that facilitated transoral robotic surgery.

Objective

To evaluate a new single-port robotic surgical system in head and neck surgery prospectively through concurrent nonrandomized clinical trials.

Design, Setting, and Participants

Two prospective clinical trials were conducted from December 16, 2016, to December 26, 2017, to assess the safety, feasibility, and performance of a flexible single-port robotic surgical system in 4 institutions, including 3 in the United States and 1 in Hong Kong. A total of 47 patients with tumors of the oropharynx were enrolled and underwent surgery. All patients were classified as having American Society of Anesthesiologists class I to III status and Eastern Cooperative Oncology Group status 0 to 1. An initial cohort of 7 patients underwent staging and endoscopic procedures for benign disease. The remaining 40 patients all had malignant tumors of the oropharynx.

Main Outcomes and Measures

Safety was measured by the incidence of device-related serious adverse events. Feasibility and performance were measured by the conversion rate from the use of the single-port robotic surgical system to either open surgery or the use of any other transoral technology required to complete the planned procedure. Secondary end points of swallowing function and surgical margins were also measured.

Results

All 47 patients (8 women and 39 men; mean [SD] age, 61 [8] years) safely underwent transoral resection with the single-port robotic surgical system without conversion to open surgery, laser surgery, or multiport robotic surgery. There were no intraoperative complications or device-related serious adverse events. Mean (SD) estimated intraoperative blood loss per procedure was 15.4 (23.9) mL; no patients received a transfusion. Two patients underwent a planned tracheotomy owing to medical comorbidity (previous chemoradiotherapy; obesity and severe sleep apnea). Two patients (4%) had grade III or IV postoperative hemorrhage, requiring a return to the operating room; however, both patients had medical comorbidities requiring the use of antithrombotic medication. The incidence of positive margins for patients with oropharyngeal malignancy was 3% (1 of 40). Within 30 days, 45 patients (96%) were eating by mouth and without the need for a percutaneous endoscopic gastrostomy tube.

Conclusions and Relevance

This study describes the results of phase 2 clinical testing of a next-generation, robotic surgical system using a single-port architecture. The use of the device appears to be feasible, safe, and effective for transoral robotic surgery of oropharyngeal tumors.

Trial Registration

ClinicalTrials.gov identifiers: NCT03010813 and NCT03049280.

Significance of nucleic acid testing in window period donations: Revisiting transfusion safety in high prevalence-low resource settings

Background: Safe blood transfusion to the people is essential requirement of health care delivery system. Despite the mandatory screening of blood with newest, very sensitive serological test, considerable risk remains for transfusion transmission of virus due to window period infections.  Study was aimed to analyze the efficacy of Mini pool Nucleic Acid Amplification Testing as additional donor screening program and its role in improving blood safety in the high prevalence population. Material and Methods: Study was performed at a tertiary-care, accreditated hospital from June 2013 to December 2015 All negative cases for anti-HIV, anti-HCV and HBsAg by ELISA were subjected to MP-NAT to detect HIV-1, HIV-2 and HCV-RNA with HBV DNA.Results: In 31 months, 20470 donations were received of which whole blood donations were 16997 (83.03%) and 3473 (16.97%) apheresis. Out of 16997 donations, 446 (2.61%) were seroreactive. Out of 16551 sero-negative donors subjected to MP-NAT testing, 17 (0.10%) were NAT reactive (NAT yield -1 in 974). Out of 17 cases, 12 were HBV (1 in 1379), four HCV (1 in 4138) and one HIV NAT reactive (1 in 16551). Conclusion: NAT has improvised the blood safety by detecting the virus in the pre-seroconversion, window period thereby providing much higher sensitivity as compared to newest generation serological tests. In countries with high incidence of infection with significant number of window period donations, NAT can serve as a valuable tool along with other serological testing in high prevalence, resource constrained countries to achieve the goal of zero risk of blood. 

A critical appraisal of cesarean section rates at teaching hospitals in India

OBJECTIVES

To obtain an estimate of cesarean section rates and examine the indications and consequences at teaching hospitals in India.

METHODS

Information was obtained on total number of normal and cesarean deliveries during 1993-1994 and 1998-1999 from 30 medical colleges/teaching hospitals. In addition, prospective data were recorded for a period of 2 months on 7017 consecutive cesarean sections on indications for cesarean delivery, associated complications and mortality.

RESULTS

The overall rate of cesarean section increased from 21.8% in 1993-1994 to 25.4% in 1998-1999. Among the 7,017 cesarean section cases, 42.4% were primigravidas, 31% had come from rural areas, 20.8% were referred including 8% with history of interference, 66% were booked cases, period of gestation was less than 37 weeks in 21.7% and in 18% the surgery was elective. Major indications for cesarean section included dystocia (37.5%), fetal distress with or without meconium aspiration (33.4%), repeat section (29.0%), malpresentation (14.5%) and PIH (12.5%). Maternal and perinatal mortality was 299/100,000 and 493/1,000 deliveries, respectively, and is high in spite of the increase in the cesarean section rates.

CONCLUSIONS

There is need for standardized collection of information on all aspects of childbirth to ascertain the incidence and indications of cesarean section nationally so that comparison and improvements of care can take place.

Antidepressant drugs and generic counselling for treatment of major depression in primary care: randomised trial with patient preference arms

OBJECTIVES

To compare the efficacy of antidepressant drugs and generic counselling for treating mild to moderate depression in general practice. To determine whether the outcomes were similar for patients with randomly allocated treatment and those expressing a treatment preference.

DESIGN

Randomised controlled trial, with patient preference arms. Follow up at 8 weeks and 12 months and abstraction of GP case notes.

SETTING

31 general practices in Trent region.

PARTICIPANTS

Patients aged 18-70 who met research diagnostic criteria for major depression; 103 patients were randomised and 220 patients were recruited to the preference arms.

MAIN OUTCOME MEASURES

Difference in mean Beck depression inventory score; time to remission; global outcome assessed by a psychiatrist using all data sources; and research diagnostic criteria.

RESULTS

At 12 months there was no difference between the mean Beck scores in the randomised arms. Combining the randomised and patient preference groups, the difference in Beck scores was 0.4 (95% confidence interval -2.7 to 3.5). Patients choosing counselling did better than those randomised to it (mean difference in Beck score 4.6, 0.0 to 9.2). There was no difference in the psychiatrist's overall assessment of outcome between any of the groups. 221/265 (83%) of participants with a known outcome had a remission. Median time to remission was shorter in the group randomised to antidepressants than the other three groups (2 months v 3 months). 33/221 (15%) patients had a relapse.

CONCLUSIONS

Generic counselling seems to be as effective as antidepressant treatment for mild to moderate depressive illness, although patients receiving antidepressants may recover more quickly. General practitioners should allow patients to have their preferred treatment.

Assessing effectiveness of treatment of depression in primary care. Partially randomised preference trial

BACKGROUND

There is a mismatch between the wish of a patient with depression to have counselling and the prescription of antidepressants by the doctor.

AIMS

To determine whether counselling is as effective as antidepressants for depression in primary care and whether allowing patients to choose their treatment affects their response.

METHOD

A partially randomised preference trial, with patients randomised to either antidepressants or counselling or given their choice of either treatment. The treatment and follow-up were identical in the randomised and patient preference arms.

RESULTS

There were 103 randomised and 220 preference patients in the trial. We found: no differences in the baseline characteristics of the randomised and preference groups; that the two treatments were equally effective at 8 weeks, both for the randomised group and when the randomised and patient preference groups for a particular treatment were combined; and that expressing a preference for either treatment conferred no additional benefit on outcome.

CONCLUSIONS

These data challenge several assumptions about the most appropriate treatment for depression in a primary care setting.

Cotinine replacement levels for a 21 mg/day transdermal nicotine patch in an outpatient treatment setting

This study examined plasma cotinine replacement levels of 56 outpatient smokers administered a 21 mg/day transdermal nicotine patch (Nicoderm CQ ). The percentage of cotinine replacement ranged from 35 to 232% (mean 107%; median 90.5%). Four subject variables were found to be significantly correlated with percentage of cotinine replacement-baseline cotinine level, prior quit attempts, gender, and the Fagerström Tolerance Questionnaire score. A two-variable model consisting of baseline cotinine level and gender provided the most powerful predictor combination. The percentage of cotinine replacement was not predictive of post-treatment smoking. The relatively high levels of cotinine replacement obtained using the Nicoderm CQ 21 mg/day patch suggest cautious use of higher dose treatment with this particular patch.