Large multicenter evaluation of clinical outcomes of transcatheter aortic valve implantation in different age groups: results from the Israeli TAVI registry

Introduction

Transcatheter aortic valve implantation (TAVI) is becoming the preferred treatment for elderly patients with severe aortic stenosis. Clinical outcomes of these patients according to different age groups and especially in the very old population are under reported.

Purpose

To describe clinical characteristics at baseline, according to different age groups, and to compare clinical outcomes in the very old population with other patients undergoing the procedure.

Methods

Data was extracted from the Israeli National TAVI Registry. Clinical outcomes in very old patients (above the age of 90 years) were compared with younger patients. Multivariable analysis for 30-day and 1-year mortality were performed. Procedural complication was defined as one or more of the following: need for permanent pacemaker, major vascular complication, severe acute kidney injury and major stroke.

Results

A total of 5,936 patients who underwent TAVI from 2008 to 2021 were analyzed (age 81.6±7.1 years, 50.6% female). Patients older than 90 years of age had more comorbidities than the younger population (STS score for mortality 6.4%±3.8% vs. 4.1%±4.8%, p<0.001). Independent correlates for 30-day mortality included STS score (OR=1.01, 95% CI [1.03–1.13], p<0.001) and procedural complication (OR=4.29, 95% CI [2.24–8.20], p<0.0001). Independent correlates for 1-year mortality included chronic obstructive pulmonary disease (OR=1.83, 95% CI [1.28–2.60]; p=0.001), atrial fibrillation (OR=1.71, 95% CI [1.31–2.23]; p<0.001 (STS score); OR=1.13 95% CI [1.09–1.18]; p<0.001), and procedural complication) OR=2.58, 95% [1.89–3.50]; p<0.001).

Conclusions

Although older patients undergoing TAVI had a higher risk profile, short- and long-term survival of these patients were associated significantly more with procedural complications than with patient age. It seems that extreme patient age alone should not be viewed as a consideration for not performing valve replacement, as long as the risk for procedural complications does not seem to be severely elevated.

Funding Acknowledgement

Type of funding sources: None.

Outcomes of patients treated with blood transfusion in a contemporary tertiary intensive cardiac care unit

Background

Different trials showed that patients treated with blood transfusion (BT) have unfavorable prognosis regarding outcomes and mortality. Nevertheless, outcomes in patients treated with BT hospitalized in a contemporary tertiary intensive cardiac care unit (ICCU) is limited.

Objective

To determine mortality rate in patients treated with BT in a contemporary tertiary ICCU.

Methods

A prospective single center study to evaluate short- and long-term mortality rate of patients treated with BT between January 2020 and December 2021 in a tertiary ICCU.

Outcomes

During the study period 2132 consecutive patients were admitted with a mean age of 66.9±16 and 650 (30.5%) of them were women. Of the total population, 108 (5%) patients were treated with BT (BT-group) during their hospitalization. Patients were followed-up for 2 years with a median [IQR] follow up time of 82.5 [12.25–240.50] days in BT-group vs. 138.5 [34–325, 75] days in the non-BT (NBT) group. Mean age was 73.81±14 years in BT-group vs. 66.59±16 years in NBT-group, p<0.0001. There was a higher rate of female gender in the BT-group 48.1% vs. 29.5% in the NBT, p<0.0001. Crude mortality rate was 29.6% in BT-group and 9.2% in NBT-group, p<0.0001. Median [IQR] length of stay was 5 [2–6] days in BT-group vs. 3 [2–4] days in the NBT-group. Multivariate Cox analysis for (Female gender, prior trans-catheter aortic valve replacement, prior cardiac intervention, sepsis, history of congestive heart failure, pulmonary hypertension, pacemaker implantation and anemia) showed that BT was independently associated with more than two folds the mortality rate [HR=2.19 95% CI (1.47–3.62)] as compared with the NBT-group, p<0.0001. Receiver operating characteristic curve (ROC) was plotted for multivariable analysis and showed area under curve (AUC) of 0.8, 95% CI [0.760–0.852].

Conclusion

Even in contemporary tertiary ICCU, with advanced technology, equipment and delivery of care, BT remains a strong predictor for short- and long-term mortality.

Funding Acknowledgement

Type of funding sources: None.

COVID-19 pandemic and admission rates for and management of acute coronary syndromes in Israel

Background

Since the COVID-19 pandemic outbreak several countries have reported a decrease in the number of patients admitted with non-ST elevation myocardial infarction (NSTEMI).

Purpose

We aimed to evaluate admission trend and outcomes of patients with NSTEMI in the COVID-19 era in a nationwide survey.

Methods

A prospective, multicenter, observational, nationwide study involving 13 medical centers across Israel. All NSTEMI patients admitted to intensive cardiac care units (ICCUs) over an 8-week period during the COVID-19 outbreak were compare them with NSTEMI patients admitted 2 years earlier (control period) during the Acute Coronary Syndrome Israeli Survey (ACSIS) 2018.

Results

There were 624 (43%) NSTEMI patients, of them 349 (56%) hospitalized during the COVID-19 era and 275 (44%) during the control period, representing a 27% increase in NSTEMI admission rate during the COVID-19 era. Approximately 76% were male, median age was 67 years (IQR 58–76). There were no differences in baseline characteristics between the two study periods. During the COVID-19 era, more patients arrived at the hospital via an emergency medical system (EMS) compared with the control period (p for trend = 0.005)

Time from symptom onset to hospital admission was longer in the COVID-19 era [687.00 (IQR147–2805) vs. 178.00 (IQR 102- 407), respectively, p-value <0.001]. Nevertheless, time from hospital admission to reperfusion was similar in both groups. Rate of percutaneous coronary intervention was higher in the COVID-19 era group (91.3% vs. 59.7%, respectively, p<0.001). In-hospital mortality rate was similar in both groups (2.3% vs. 4.7%, respectively, p=0.149) as was the 30-day mortality rate (3.7% vs. 5.1%, respectively, p=0.238).

Conclusions

In contrast to previous reports, in Israel, admission rate of NSTEMI was increased during the COVID-19 era. With longer time from symptoms to admission, but with the same time from hospital admission to reperfusion therapy and with similar in-hospital and 30-day mortality rates.

Funding Acknowledgement

Type of funding sources: None.

Acute myocardial infarction in the Covid-19 era: incidence, clinical characteristics and in-hospital outcomes – a multicenter registry

Background

A reduction in acute myocardial infarction (AMI) hospitalizations during the coronavirus pandemic has been previously documented. We aimed to describe the characteristics and in-hospital outcomes of AMI patients during the Covid-19 era compared to a recent previous registry.

Methods

We conducted a prospective, multicenter, observational study involving 13 intensive cardiac care units (ICCUs) to evaluate consecutive AMI patients admitted throughout an 8-week period during the Covid-19 outbreak. Data were compared to the corresponding period in 2018 using an acute coronary syndrome survey conducted in all ICCUs in Israel. The primary end-point was defined as a composite of sustained ventricular arrhythmia, pulmonary congestion, and/or in-hospital mortality.

Results

The study cohort comprised 1466 patients, of whom 774 (53%) were hospitalized during the Covid-19 outbreak. Overall, 841 patients were diagnosed with ST-elevation MI (STEMI): 424 (50.4%) during the Covid-19 era and 417 (49.6%) during the parallel period in 2018. No differences were detected in the admission rate of patients between the two study periods. STEMI patients admitted during the Covid-19 period tended to have fewer co-morbidities, but a higher Killip class (p value = 0.03). The median time from symptom onset to reperfusion was extended from 180 minutes (IQR 122–292) in 2018 to 290 minutes (IQR 161–1080, p<0.001) in 2020. Hospitalization during the Covid-19 era was independently associated with an increased risk of the combined endpoint of heart failure, malignant arrhythmia, or death in the multivariable logistic regression model (OR 1.63, 95% CI 1.02–2.65, p value = 0.05).

Conclusion

While the admission rate of AMI and STEMI in Israel remained similar during both the Covid-19 era and the corresponding period in 2018, total ischemic time extended significantly during the Covid-19 period, which translated into a more severe disease status upon hospital admission, and a higher rate of in-hospital adverse events.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by a grant from a Fefer foundation for medical research

The prevalence and characteristics of patients with ST-elevation myocardial infarction during the first two months of the COVID-19 pandemics

Background

ST-Segment elevation MI (STEMI) is one of the leading cause of mortality in the western world. The coronavirus disease-2019 (COVID-19) pandemic might have implications of the treatment of STEMI patients. Our aim was to evaluate the treatment of STEMI patients during 2 months of the COVID-19 pandemic as compared with the year before.

Methods

Data of 90 STEMI patients treated at the Shaare Zedek Medical Center intensive coronary care unit (ICCU) Between March-April 2019 and March-April 2020 were collected. Patients were divided into 2 groups: The pre COVID-19 group and the COVID-19 era group. Data regarding complications upon arrival and during hospitalization, door to balloon time and echocardiographic exams.

Results

Fifty one (56%) patients were admitted with STEMI in the pre COVID-19 group and only 39 (44%) in the COVID-19 era group. Of them 13.7% vs. 20.5% were female, p=0.392 with a mean age of 62.1 (±13.5) vs. 63.4 (±11) years old, p=0.635 in the pre vs. post COVID-19 era group, respectively. Interestingly, more Jewish vs. non-Jewish were admitted with STEMI in the COVID-19 era group. There were no differences regarding baseline characteristics, catheterization access, culprit vessel and percutaneous coronary intervention rate. Door to balloon time was also similar in both pre and post COVID-19 era groups 35.4 (±32) vs. 30.5 (±29.1) minutes (p=0.896). Moreover, there was no difference regarding infarct size. Complications including acute renal failure, cardiogenic shock, and the use of intra-aortic balloon pump were similar in both groups. 30-day mortality rate was low and similar in both pre and post COVID-19 era groups (5.9% vs. 2.6%, respectively, p=0.426).

Conclusions

During the beginning of COVID-19 era there was a reduction in STEMI admission rate, while no significant difference was found regarding baseline characteristics, door to balloon time, infarct size and mortality rate

Funding Acknowledgement

Type of funding sources: None.

Cardiac and other presentation and clinical outcomes of COVID-19 pandemic among different ethnic and religious populations in the city of Jerusalem

Background

The COVID-19 pandemic is an ongoing global pandemic. Jerusalem with its 919,400 inhabitants has a wide variety of populations, of which 62% are Jews (36% ultra-orthodox; 64% non-ultraorthodox) and 38% Arabs which were largely affected by the pandemic.

Objectives

The aim of our study was to understand the different presentations, course and clinical outcomes in these different ethnical and cultural groups in Jerusalem in the COVID-19 pandemic.

Methods

We performed a cohort study of all COVID-19 patients admitted between March 9 - July 16, 2020 to the two university medical centers in Jerusalem. Demographic data, presenting symptoms, comorbid conditions, medications, physical examination, laboratory and imaging data as well as outcome at 30-day were systematically recorded. Patients were divided according to their religion and ethnicity into 3 main groups: 1) Ultra-Orthodox Jews; 2) other (non-Ultra-Orthodox) Jews and 3) Arabs.

Results

Six hundred and two patients comprised the study population. Of them the 361 (60%) were Ultra-Orthodox Jews; 166 (27.5%) non-Ultra-Orthodox Jews and 75 (12.5%) Arabs. The Arab patients were younger than the Ultra-Orthodox Jews and the non-Ultra-Orthodox Jews (51±18 year-old vs. 57±21 and 59±19, respectively, p<0.01), but suffered from significantly more co-morbidities. Fever, cough, dyspnea and fatigue, were more prominent, as presenting symptoms, in the Jewish patients as compared with the Arab patients. Moreover, hemodynamic shock, ischemic ECG changes and pathological chest x-ray were all more frequent in the Ultra-Orthodox patients as compared the other groups of patients. Being an Ultra-Orthodox was independently associated with significantly higher rate of Major Adverse Cardiovascular Events (MACE) [OR=1.96; 95% CI (1.03–3.71), p<0.05]. Age was the only independent risk factor associated with increased mortality rate [OR=1.10; 95% CI (1.07–1.13), p<0.001].

Conclusions

The COVID-19 first phase in Jerusalem, affected different ethnical and cultural groups differently, with the Ultra-Orthodox Jews mostly affected by admission rates, presenting symptoms clinical course and MACE (Acute coronary syndrome, shock, cerebrovascular event or venous thromboembolism). It is conceivable that vulnerable populations need special attention and health planning in time of pandemic, to prevent rapid distribution and severe morbidity.

Funding Acknowledgement

Type of funding sources: None.

D-dimer as a prognostic factor in patients admitted to a tertiary care intensive coronary care unit

Introduction

D-dimer is a small protein fragment and is a product of fibrinolysis. A high levels of D-dimer have been suggested as a prognostic factor in cancerous and other critically ill patients. We aimed to evaluate D-dimer levels and outcomes of critically ill patients admitted to a tertiary care intensive coronary care unit (ICCU).

Material and method

All patients admitted to the ICCU at our Medical Center between January 1, 2020 and December 31, 2020 were included in the study. Patients were divided into 2 groups according to their D-dimer level on admission. Low D-dimer level <500 ng/ml, and high D-dimer level ≥500 ng/ml. Survival, in-hospital interventions and complications were compared.

Results and discussion

Overall 1,082 consecutive patients were included, mean age was 67 (±16), 70% were males. Of them 296 (27.4%) had low D-dimer level and 663 (61.3%) had high D-dimer level. Patients with high D-dimer level were older as compared to patients with low D-dimer level (mean age 70.4±15 and 59±13 years respectively, p=0.004), had significantly higher rate of female gender (35.9% vs 15.9% respectively, p<0.0001) and significantly higher rate of any prior cardiac interventions prior to their admission (26.7% vs 4.4% respectively, p<0.0001). Interestingly, patients with high D-dimer level had significantly lower rate of any acute coronary syndrome (ACS) as compared with the low D-dimer group (25.7 vs 66.4% respectively, p<0.0001) and lower rate of smokers (22.5 vs 45.6% respectively, p<0.0001). All 11 post-COVID-19 patients had high D-dimer level on admission.

A multivariate Cox proportional hazards analysis for mortality, adjusted for age, gender, risk factors for cardiovascular disease, ejection fraction<40 found that high D-dimer level was independently associated with higher mortality rates (HR=5.8; 95% CI; 1.7–19.1; p=0.004) as shown in Figure 1.

Conclusion

Elevated D-dimer levels on admission in ICCU patients is a poor prognostic factor of in-hospital morbidity and mortality in the first year following hospitalization.

Funding Acknowledgement

Type of funding sources: None. Cumulative survival according to d-Dimer

The association between statin pre-treatment and LDL Levels on the rate of STEMI presentation: data from the ACS Israeli Survey (ACSIS) 2008–2018

Background

ST-elevation myocardial infarction (STEMI) mostly occurs as a result of vulnerable coronary artery plaque rupture. Constituting hypolipidemic and pleiotropic effects, statins stabilize coronary artery plaque and may prevent STEMI events.

Purpose

To determine the association between statin pre-treatment and its intensity, low-density-lipoprotein cholesterol (LDL-C) levels and presentation of patients with an ACS (STEMI vs. NSTEMI/unstable angina [UAP]).

Methods

Data was drawn from the Acute Coronary Syndrome Israeli Survey (ACSIS), a biennial prospective survey of ACS patients hospitalized in all CCU/Cardiology departments during 2008–2018. The rate of STEMI vs NSTEMI/UAP at the time of presentation was calculated by LDL-C levels on admission, stratified to 5 subgroups (<50, 50–69, 70–100, 101–130 and >130 mg/dl) and the use of statins, including statin intensity prior to the index ACS event.

Results

Among 5,103 patients, 875 (17%) were pre-treated with high intensity statin (HIST), 1,389 (27%) with low intensity statin (LIST), and 2,839 (56%) were statin naive patients. Statin-pre-treated patients were older, more likely to suffer from co-morbidities and cardiovascular diseases and were more often pre-treated with anti-platelets.

The proportion of patients presenting with STEMI vs. NSTEMI/UAP was significantly lower among HIST vs. LIST vs. statin naive patients (31.0%, 37.8%, 54.0%, respectively, p for trend <0.001). At each LDL-C level, the proportion of STEMI was significantly lower among HIST vs. LIST vs. statin naive patients. Multivariate analysis adjusting for pertinent variables including propensity score for statin use, revealed that HIST was independently associated with lower STEMI presentation, but LDL-C<70 and LIST were not.

Conclusions

Among patients admitted with ACS, pre-treatment with high intensity statin but not LDL-C level, was independently associated with a lower probability of presenting with STEMI.

Funding Acknowledgement

Type of funding source: None

Aspirin withdrawal in patients treated with ticagrelor presenting with non-ST elevation myocardial infarction

Essentials Strong P2Y12 blockade may cause platelet inhibition that is only minimally enhanced by aspirin. We evaluated aspirin withdrawal on platelet reactivity in ticagrelor treated patients. Aspirin withdrawal resulted in increased platelet reactivity to arachidonic acid. Aspirin withdrawal caused little difference in adenosine diphosphate-induced platelet aggregation.

SUMMARY

Background Recent studies have shown that the thromboxane A2 -dependent pathway is dependent on the ADP-P2Y12 pathway, and that strong P2Y12 receptor blockade alone causes inhibition of platelet aggregation that is minimally enhanced by aspirin. Data from the PLATO trial suggested that, among ticagrelor-treated patients, high-dose versus low-dose (< 100 mg day-1 ) aspirin is associated with an increased risk fof ischemic events. Objectives To evaluate the impact of aspirin withdrawal on platelet reactivity in acute coronary syndrome (ACS) patients treated with a potent P2Y12 blocker. Patients/Methods This was a current prospective, randomized, placebo-controlled, double-blind, cross-over study. The study population comprised 22 consecutive ACS patients who underwent percutaneous coronary intervention and were treated with aspirin (100 mg day-1 ) and ticagrelor. Thirty days post-ACS, open-label aspirin was stopped, and patients were randomized to either blinded aspirin or placebo for 2 weeks, with each patient crossing over to the other arm for an additional 2 weeks. Platelet reactivity to arachidonic acid and ADP determined with light-transmission aggregometry (LTA) and VerifyNow was evaluated at baseline, and 2 weeks and 4 weeks later. Results Aspirin withdrawal resulted in an increase in arachidonic-acid induced platelet reactivity as determined with both LTA (77.0% ± 11.3% versus 20.8% ± 4.4%) and VerifyNow (607.7 ± 10.6 aspirin reaction units [ARU] versus 408.5 ± 14.4 ARU). Platelet response to ADP, as determined with both LTA and VerifyNow, did not differ with either aspirin or placebo (32.9% ± 2.6% versus 35.8% ± 3.6%, and 33.5 ± 6.4 P2Y12 reaction units (PRU) versus 29.6 ± 5.7 PRU, respectively). Conclusions Aspirin withdrawal early post-ACS results in increased platelet reactivity in response to arachidonic acid, despite concomitant treatment with the potent P2Y12 blocker ticagrelor.

Anterior ST-elevation myocardial infarction induced by rituximab infusion: A case report and review of the literature

WHAT IS KNOWN AND OBJECTIVES

Rituximab is a chimeric monoclonal anti-CD20 antibody approved for the treatment of some lymphoid malignancies as well as for autoimmune diseases including rheumatoid arthritis (RA), idiopathic thrombocytopenic purpura (ITP) and vasculitis. Generally, rituximab is well tolerated; nevertheless, some patients develop adverse effects including infusion reactions. Albeit rare, these reactions may in some cases be life-threatening conditions. Rituximab cardiovascular side effects include more common effects such as hypertension, oedema and rare cases of arrhythmias and myocardial infarction.

CASE SUMMARY

In this article, we report a case of a 58-year-old man with a history of overlap syndrome including RA and limited scleroderma who was treated with rituximab and developed a dramatic ST-elevation myocardial infarction (STEMI) during the drug administration.

WHAT IS NEW AND CONCLUSION

This report underlines previous published reports emphasizing the awareness of such an association. This communication also warrants the importance of screening for ischaemic heart disease in selected cases of patients treated with rituximab.

Increased mean platelet volume is associated with non-responsiveness to clopidogrel

Prior studies have demonstrated significant individual variability of platelet response to clopidogrel, which affects clinical outcome. In patients with stable coronary artery disease (CAD) smoking, diabetes mellitus, elevated body mass index and renal insufficiency, significantly impact response to clopidogrel. The determinants of platelet response to clopidogrel in patients with acute coronary syndrome are unknown. Adenosine diphosphate (ADP)-induced platelet aggregation (PA), hs C-reactive protein, platelet count and mean platelet volume (MPV) were determined 72 hours post clopidogrel loading in 276 consecutive acute myocardial infarction (AMI) patients. Patients with ADP-platelet aggregation ≥ 70% were considered to be clopidogrel non-responders. Eighty-four patients (30%) were clopidogrel non-responders and 192 (70%) were responders (ADP-induced PA: 81 ± 17% vs 49 ± 17%, respectively, p<0.001). Both study groups were comparable with respect to age, gender, prior cardiovascular history, prior aspirin use and risk factors for CAD, including smoking (42% for both groups) and diabetes mellitus (26% vs 22%, respectively, p=0.4). Responders and non-responders had similar angiographic characteristics, indices of infarct size, and similar hs-CRP (29 ± 34 vs 28 ± 34 mg/l, p=0.7) and creatinine (1.08 ± 0.4 mg% vs 1.07 ± 0.4, p=0.9) levels. On the contrary non-responders had significantly larger mean MPV (9 ± 1.2 fl vs 8 ± 1 fl, respectively, p=0.0018), and when patients were stratified into quartiles based on MPV, ADP-induced PA increased gradually and significantly across the quartiles of MPV (p<0.001). In conclusion, increased MPV associated with platelet activation, predicts non-responsiveness to clopidogrel among patients with acute coronary syndrome.

Superficial vein thrombophlebitis as a marker of hypercoagulability

Superficial thrombophlebitis (SVT)is a common disorder with potential morbidity from recurrence and pulmonary embolism (PE), but it has received little attention in the literature. The availability of reliable duplex ultrasonography of the deep and superficial venous systems has made routine determination of the location and incidence of deep vein thrombosis (DVT) in association with SVT practical.

Traps for young players: when the well selected remedy fails to act

Two cases of apparent failure to respond to well-indicated homeopathic treatment are presented in a case of nephrotic syndrome, there was dramatic response to exclusion of food of bovine origin. A case presenting with palpitation seemed to respond to Naja, but proved to have a pheochromocytoma which was successfully resected. The clinical lessons learnt are discussed.

Evaluation of cell death in EBV-transformed lymphocytes using agarose gel electrophoresis, light microscopy and electron microscopy. II. Induction of non-classic apoptosis ("para-apoptosis") by tritiated thymidine

There is an extensive literature dating back to the late 1950's, on the damaging biological effects of radiolabeling DNA in vivo. Nonetheless, tritiated thymidine has often been used to label DNA in studies of programmed cell death (apoptosis). In the present study, we have investigated the effects of incorporation of tritiated thymidine into the DNA of an Epstein-Barr virus-transformed cell line (NC-37) in the absence of any other apoptosis-inducing agent. Cells were incubated in media containing 1-20 microCi/ml [methyl-3H]-thymidine ([3H]-TdR). At each concentration of tritiated thymidine used, cell proliferation ceased within 12 hours of incubation. The mode of cell death caused by tritiated thymidine incorporation was evaluated using DNA degradation patterns and cellular morphology. DNA degradation, in the absence of a "ladder" pattern, was shown by agarose gel electrophoresis. Electron microscopy was used as the "gold standard" to evaluate the specific morphologic type of cell death that accompanied the DNA degradation. Although some of the features of apoptosis were present, the cells lacked the early margination of the chromatin within an intact nucleus and surface blebbing leading to apoptotic body formation, two characteristic morphological features of apoptosis. We, therefore, coined the term "para-apoptosis" to be more precise about the morphologic type of cell death. The percent of para-apoptotic cells was quantitated by light microscopy using whole mount preparations (cytospins). The morphologic criteria of chromatin condensation, nuclear fragmentation, increase in cell density and cytoplasmic vacuolization were used for the evaluation of para-apoptosis by light microscopy of cytospin preparations. In the absence of tritiated thymidine, < 2% of the cells became apoptotic/para-apoptotic after 43 hours of incubation. However, at all concentrations of tritiated thymidine used in the incubation medium (1-20 microCi/ml), the number of para-apoptotic cells increased. In addition, we detected perturbations in the timing of the cell cycle of the surviving cells and an increase in the number of micronuclei after only one division cycle. The induction of para-apoptosis and micronuclei formation represent two distinct modes of cell death caused by tritiated thymidine incorporation. These studies emphasize the necessity for morphological examination in characterizing the induction of cell death in a new experimental system.

Evaluation of cell death in EBV-transformed lymphocytes using agarose gel electrophoresis, light microscopy and electron microscopy. I. Induction of classic apoptosis by the bile salt, sodium deoxycholate

In this study, we examined the effect of different concentrations of sodium deoxycholate (NaDOC), a secondary bile salt, on an Epstein-Barr virus transformed human lymphoid cell line (NC-37). We found that NaDOC induces classic apoptosis in a dose-dependent manner at 0.1-0.4 mM doses, and necrosis at much higher concentrations (0.8-3.1 mM). This is the first demonstration that a bile salt can induce apoptosis in any cell type. The mode of cell death was determined using morphologic methods (light and electron microscopy) as the gold standard. Standard agarose gel electrophoretic techniques were applied to identify the "ladder" of DNA fragments that have been associated with apoptosis in certain cell types. Although DNA fragmentation was observed during the apoptotic death of NC-37 cells, we were not able to identify a "ladder" pattern of fragmentation. Two other types of cells, however, that previously have been reported to display a characteristic "ladder" pattern of DNA fragmentation, glucocorticoid-treated WEHI7.2 cells and isolated human neutrophils, did display the "ladder" pattern. This study emphasizes the need to examine morphology when identifying the mode of cell death induced by a new agent.