Innate immune response against HPV: Possible crosstalking with endocervical γδ T cells.

Cervical carcinoma is significantly associated with the human papillomavirus (HPV). Persistent infection with high risk-HPV is necessary but not sufficient for the development of cervical cancer. It is not fully understood which immunological mechanisms lead to persistence in some patients. During the life cycle, HPV uses excellent immune evasion mechanisms. Keratinocytes, Langerhans cells (LC), dendritic cells (DC), tissue-resident macrophages, and intraepithelial gamma-delta T cells (γδ T cells) are cellular components of the mucosal immune defense of the female genital tract against HPV. γδ T cells, the prototype of unconventional T cells, play a major role in the first line defense of epithelial barrier protection. γδ T cells connect the innate and adaptive immunity and behave like a guardian of the epithelium against any form of damage such as trauma and infection. Any changes in γδ T cell distribution and functional capability may have a role in persistent HPV infection and cervical carcinogenesis in the early phase. Poor stimulation and maturation of APCs (LC/DC) might lead to persistent HPV infection which all point out pivotal role of γδ T cells in HPV persistence. If such an intriguing link is proven, γδ T cells can be used in potential therapeutics against HPV in infected patients.

Methodology of a new inflammatory arthritis registry: TReasure

Background/aim: The TReasure registry, created in 2017, is an observational multicenter cohort that includes inflammatory arthritis patients. This article reviews the methodology and objectives of the TReasure registry established to collect data from rheumatoid arthritis (RA) and spondyloarthritis (SpA) patients. Methodology: Fifteen rheumatology centers in Turkey will contribute data to the TReasure database. The actual proprietor of the database is the Hacettepe Rheumatology Association (HRD) and Hacettepe Financial Enterprises. Pharmaceutical companies that operate in Turkey (in alphabetical or er), Abbvie, Amgen, BMS, Celltrion Healthcare, Novartis, Pfizer, Roche, and UCB, support the TReasure registry. TReasure is a web-based database to which users connect through a URL (https://www.trials-network.org/treasure) with their unique identifier and passwords provided for data entry and access. TReasure records demographic and clinical features, comorbidities, radiology and laboratory results, measures of disease activity, and treatment data. Discussion: TReasure will provide us with various types of data, such as a cross-sectional view of the current nationwide status of the patients currently receiving these treatments, and retrospective data as much as allowed by the participating centers' records. Finally, a high-quality prospective dataset will be built over the ensuing years from patients with a new diagnosis of RA or SpA.

Direct and indirect healthcare costs of rheumatoid arthritis patients in Turkey.

OBJECTIVES: To estimate the annual cost of rheumatoid arthritis (RA) in Turkey by obtaining real-world data directly from patients. METHODS: In this cross-sectional study, RA patients from the rheumatology outpatient clinics of 10 university hospitals were interviewed with a standardised questionnaire on RA-related healthcare care costs. RESULTS: The study included 689 RA patients (565 females) with a mean age of 51.2±13.2 years and mean disease duration of 9.4±7.8 years. The mean scores of the Routine Assessment of Patient Index Data 3 and the Health Assessment Questionnaire-Disability Index (5.08±2.34 and 1.08±0.68, respectively) indicated moderate disease activity and severity for the whole group. One-third of the patients were on biologic agents and 12% had co-morbid conditions. The mean number of annual outpatient visits was 11.7±9.6 per patient. Of the patients, 15% required hospitalisation and 4% underwent surgery. The mean annual direct cost was € 4,954 (median, € 1,805), whereas the mean annual indirect cost was € 2,802 (median, € 608). Pharmacy costs accounted for the highest expenditure (mean, € 2,777; median, € 791), followed by the RA-related consultations and expenses (mean, € 1,600; median, € 696). CONCLUSIONS: RA has a substantial economic burden in Turkey, direct costs being higher than indirect costs. Although both direct and indirect costs are lower in Turkey than in Europe with respect to nominal Euro terms, they are higher from the perspectives of purchasing power parity and gross domestic product. Early diagnosis and treatment of RA may positively affect the national economy considering the positive correlation between health care utilisations and increased cost with disease severity.

Characteristics Predicting Tuberculosis Risk under Tumor Necrosis Factor-α Inhibitors: Report from a Large Multicenter Cohort with High Background Prevalence.

OBJECTIVE: Screening strategies for latent tuberculosis (TB) before starting tumor necrosis factor (TNF)-α inhibitors have decreased the prevalence of TB among patients who are treated with these agents. However, despite vigilant screening, TB continues to be an important problem, especially in parts of the world with a high background TB prevalence. The aim of this study was to determine the factors related to TB among a large multicenter cohort of patients who were treated with anti-TNF. METHODS: Fifteen rheumatology centers participated in this study. Among the 10,434 patients who were treated with anti-TNF between September 2002 and September 2012, 73 (0.69%) had developed TB. We described the demographic features and disease characteristics of these 73 patients and compared them to 7695 patients who were treated with anti-TNF, did not develop TB, and had complete data available. RESULTS: Among the 73 patients diagnosed with TB (39 men, 34 women, mean age 43.6 ± 13 yrs), the most frequent diagnoses were ankylosing spondylitis (n = 38) and rheumatoid arthritis (n = 25). More than half of the patients had extrapulmonary TB (39/73, 53%). Six patients died (8.2%). In the logistic regression model, types of anti-TNF drugs [infliximab (IFX), OR 3.4, 95% CI 1.88-6.10, p = 0.001] and insufficient and irregular isoniazid use (< 9 mos; OR 3.15, 95% CI 1.43-6.9, p = 0.004) were independent predictors of TB development. CONCLUSION: Our results suggest that TB is an important complication of anti-TNF therapies in Turkey. TB chemoprophylaxis less than 9 months and the use of IFX therapy were independent risk factors for TB development.

Impact of rheumatoid arthritis in Turkey: a questionnaire study.

OBJECTIVES: Unmet needs of rheumatoid arthritis (RA) patients regarding physician/patient communication, treatment preferences and quality of life issues were investigated in a Turkish survey study. METHODS: The study was conducted with the contribution of 33 rheumatologists, and included 519 RA patients. The study population included patients who had been on biologic therapy for >6 months and were still receiving biologic therapy (BT group), and those who were biologic naive, but found eligible for biologic treatment (NBT group). Of the RA patients, 35.5% initially had a visit to an internal disease specialist, 25.5% to a physical therapy and rehabilitation specialist, and 12.2% to a rheumatology specialist for their RA complaints. The diagnosis of RA was made by a rheumatologist in 48.2% of patients. RESULTS: The majority of RA patients (86.3%) visit their doctor within 15-week intervals. Most of the physician-patient communication focused on disease symptoms (99.0%) and impact of the disease on quality of life (61.8%). The proportion of RA patients who perceived their health status as good/very good/excellent was higher in the BT group than in the NBT group (74.3% vs. 51.5%, p<0.001). However, of those RA patients in the NBT group, only 24.8% have been recommended to start a biologic treatment by their doctors. With respect to dose frequency options, once-monthly injections were preferred (80%) to a bi-weekly injection schedule (8%). CONCLUSIONS: In conclusion, RA patients receiving biologic therapy reported higher rates of improved symptoms and better quality of life and seemed to be more satisfied with their treatment in our study.

CD40, CD45 CTLA-4 levels are elevated in healthy older adults.

BACKGROUND: The immune system changes with age. In this study we characterized immune changes by performing immunologic screening profiles on ageing individuals. METHODS: This study was performed at Akdeniz University, in the Faculty of Medicine, Department of Immunology. Healthy volunteers consisted of a younger group (22 donors) and an older group (45 individuals). All subjects had no serious health problems (i.e. chronic heart, lung, liver or immunological diseases) and were taking no prescribed medications. Flow cytometry analysis was used to evaluate CD3, CD4, CD8, CD16, CD19, CD28, CD40, CD45, CD56, CD80, CD86, CTLA-4 and ELISA for IL-1 beta, IL-2, IL-6, IL-10, IFN-gamma, TNF-alpha expression In addition, NK activity and induced cytokine expression (by bioassay and ELISA, respectively) were evaluated. RESULTS: No statistical differences were observed between the two groups in expression of CD3, CD8, CD19, CD80, CD86, CD16, CD 56, or CD28. A higher frequency of expression of CD4, CTLA-4, CD40, and CD45 was seen in older subjects by comparison with younger subjects. Cytokine profiles expressed by stimulated monocytes and lymphocytes from the two groups showed no difference in IL-1 beta, IL-2, IL-6, IL-10, TNF-alpha, and IFN-gamma production levels. CONCLUSIONS: We found increased expression levels of CD40 and CD45 levels in healthy older (age: 59.42 +/- 5.89) versus younger individuals (age: 30.32 +/- 2.29). CTLA-4 expression levels were also higher in older subjects, with no difference in CD28 expression levels between younger/older individuals.

TRAIL death receptor-4, decoy receptor-1 and decoy receptor-2 expression on CD8+ T cells correlate with the disease severity in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid Arthritis (RA) is a chronic autoimmune inflammatory disorder. Although the pathogenesis of disease is unclear, it is well known that T cells play a major role in both development and perpetuation of RA through activating macrophages and B cells. Since the lack of TNF-Related Apoptosis Inducing Ligand (TRAIL) expression resulted in defective thymocyte apoptosis leading to an autoimmune disease, we explored evidence for alterations in TRAIL/TRAIL receptor expression on peripheral T lymphocytes in the molecular mechanism of RA development. METHODS: The expression of TRAIL/TRAIL receptors on T cells in 20 RA patients and 12 control individuals were analyzed using flow cytometry. The correlation of TRAIL and its receptor expression profile was compared with clinical RA parameters (RA activity scored as per DAS28) using Spearman Rho Analysis. RESULTS: While no change was detected in the ratio of CD4+ to CD8+ T cells between controls and RA patient groups, upregulation of TRAIL and its receptors (both death and decoy) was detected on both CD4+ and CD8+ T cells in RA patients compared to control individuals. Death Receptor-4 (DR4) and the decoy receptors DcR1 and DcR2 on CD8+ T cells, but not on CD4+ T cells, were positively correlated with patients' DAS scores. CONCLUSIONS: Our data suggest that TRAIL/TRAIL receptor expression profiles on T cells might be important in revelation of RA pathogenesis.

Lung involvement in patients with primary Sjögren's syndrome: what are the predictors?

The aim of this study was to investigate the prevalence, predictors and radiological findings of primary Sjögren's syndrome (pSS)-associated lung involvement. This retrospective cohort study included 123 patients with demographic, clinical, laboratory and radiological data who were diagnosed with pSS. Lung involvement was defined based on the presence of pulmonary signs/symptoms and/or impaired pulmonary function tests along with alterations in high-resolution computerized tomography (HRCT). Thirty patients (24.4%) had pulmonary signs/symptoms at the initial presentation and/or during the follow-up period. Based on the criteria, 14 patients (11.4%) were defined as having pSS with lung involvement. The smoking rate, male/female ratio and the mean ages were found to be higher in patients with lung involvement (P < 0.05). Positive IgM-rheumatoid factor (RF), anti-La and anti-Ro results, the presence of hypergammaglobulinemia and lymphopenia had high specificity despite the low sensitivity rates to detect pSS-associated lung disease. A significant difference was found in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) results between the patients with and without lung involvement. Impaired FEV(1) had high specificity and positive predictive value compared to impaired FVC, particularly in non-smoker patients. The most frequent HRCT finding was ground-glass attenuation (64.3%). Other common findings were bronchiectasis, reticular pattern and honeycombing. The lesions involved predominantly the lower lobes. In conclusion, the presence of hypergammaglobulinemia and lymphopenia, positivity for RF, anti-La and anti-Ro, and impaired (FVC) and/or FEV(1) values could be the predictive parameters with a high specificity despite the low sensitivity rates. Smoking history, male gender and age are also risk factors. These parameters may be helpful to distinguish pSS-associated lung involvement from lung disorders unrelated to pSS.

A case of primary Sjögren's syndrome with pulmonary-limited Wegener's granulomatosis.

A 60-year-old woman had a history of dyspnea for 5-6 weeks. The chest radiograph and computed tomography scans revealed bilateral patchy reticulonodular pattern. The patient had positive test results for antineutrophil cytoplasmic antibody against proteinase-3 (c-ANCA), antinuclear antibody and anti-Ro antibody. According to European Study Group on Classification Criteria for Sjögren's Syndrome, the patient was diagnosed as primary Sjögren's syndrome based on the presence of clinical features, positive findings on Schirmer's test and parotis scintigraphy. Lung biopsy obtained by wedge resection showed granulomatous inflammation with extensive multinuclear giant cells involving the lung parenchyma and vascular structures. There was neither upper airway nor renal involvement. Thus, the patient was simultaneously diagnosed as pulmonary-limited Wegener's granulomatosis. With this unique case, we would like to emphasize that the awareness of ANCA-associated vasculitis as a diagnostic possibility in primary Sjögren's syndrome is important during the work-up of lung lesions.

Diagnostic performance of minor salivary gland biopsy, serological and clinical data in Sjögren's syndrome: a retrospective analysis.

The aim of this study was to investigate the performance of minor salivary gland biopsy (MSGB), serological and clinical data in diagnosis of primary Sjögren's syndrome (pSS). Retrospective review of 216 patients who underwent minor labial salivary gland biopsy in last 5 years was performed. Results of the patients with diagnosis of pSS were compared with the patients failing to fill the classification criteria of pSS. Two groups did not differ significantly in terms of clinical symptoms and signs except presence of Raynaud's phenomenon. Specificity and positive likelihood ratio of clinical signs in diagnosis of pSS were quiet low. A total of 78.7% of pSS patients had a focus score >or=1 (Chiscolm's score III/IV) while all of the non-SS patients had a focus score <1 (P < 0.001). MSGB has the best predictive value with highest sensitivity and specificity for pSS diagnosis. Serological markers have higher predictive values compared to clinical symptoms and signs. Presence of Raynaud's phenomenon, lymphopenia and/or hypergammaglobulinemia strengthens the probability of pSS in a patient with sicca symptoms.

Aging and the immune system.

Aging is associated with many physiological changes in a variety of organ systems. Nevertheless, considerable interest has centred on the possibility that age-related immunological changes may play a key "master" role in regulating many, if not all, subsequent events. A growing body of data, some of it highlighted in this review, supports the notion that host resistance in general is changed in both a qualitative and quantitative manner with age, though the biochemical mechanism(s) underlying such changes are not unique to the immune system per se. Moreover, interventions designed to explore treatments which may reverse some or all of those age-related changes have pointed out a fundamentally important role for nutrition, and the way(s) in which this impacts on host resistance mechanism(s), as having a hitherto unappreciated importance in immunosenescence in general.

Platelet-activating factor and P-selectin activities in thrombotic and nonthrombotic Behçet's patients.

OBJECTIVE: The aim of this study was to compare plasma Platelet-activating factor (PAF) and P-selectin (CD62P) activities in Behçet's disease patients with and without thrombosis. METHODS: In this cross-sectional and descriptive study, 30 consecutive Behçet's patients were included, 15 of them with venous thrombosis. All patients were also divided into two subgroups according to the presence or absence of clinical activity. Plasma PAF levels, basal and Ca++ ionophore (A23187)-induced leukocyte (cellular) PAF activities, and platelet-rich plasma DeltaCD62P activity (the mean fluorescent density difference between CD62P phycoerythrin-positive and -negative stains) were evaluated. RESULTS: In the thrombotic group, plasma PAF (P=0.001), basal leukocyte PAF (P=0.017), induced leukocyte PAF (P=0.024), and DeltaCD62P (P=0.023) levels were significantly higher than in the nonthrombotic group. In the whole group of Behçet's patients, there was a positive correlation between plasma PAF and DeltaCD62P levels (r=0.533, P=0.002). When we compared clinically active and inactive patients with respect to the above parameters, there was no significant difference, irrespective of thrombosis. Plasma PAF (P=0.001), basal leukocyte PAF (P=0.004), and DeltaCD62P (P=0.038) levels were significantly higher in the presence of both clinical activity and thrombosis than of clinical activity alone. CONCLUSION: Platelet-activating factor and CD62P may contribute to endothelial injury and thrombosis development in Behçet's disease. These two parameters seem related to the presence of thrombosis rather than clinical activity.

Serum transforming growth factor-beta1(TGF-beta1) in patients with cirrhosis, chronic hepatitis B and chronic hepatitis C [corrected].

Chronic liver disease and cirrhosis are two of the most important health problems according to current gastroenterology literature. Based on the recent developments in the field of immunology, advanced follow-up and treatment modalities have been introduced for these disorders. Immune defence against viral infections depends on effective cellular immune responses derived mainly from Th1-related cytokines. Th2 type immune responses can inhibit efficient immune function by secretion of several cytokines such as IL-10, TGF-beta1. In this particular study, we determined the serum levels of TGF-beta1, which plays a role in immune suppression and induction of tissue fibrosis. We evaluated the role of TGF-beta1 in the pathogenesis of chronic liver disease and cirrhosis. Fourteen chronic hepatitis B (CHB), 12 chronic hepatitis C (CHC) patients and 21 cirrhotic patients were enrolled in the study. The control group consisted of ten healthy people. Serum TGF-beta1 levels were higher in both cirrhosis and CHC group when compared to those in CHB and control groups (P < 0.05). Although serum TGF-beta1 levels in the cirrhosis group were higher than that in the CHC group, the difference was not statistically significant. In conclusion, elevated TGF-beta1 levels in patients with CHC and cirrhosis may have a role in the pathogenesis and chronicity of these diseases.

Biochemical and morphological characteristics of selenite-induced apoptosis in human hepatoma Hep G2 cells.

Selenium is a cellular growth inhibitor in many mammary tumor cells. To comprehend the mechanism for the selenium-induced cell death, we examined the effects of sodium selenite, which has been one of the most extensively investigated selenium compounds, in human hepatoma Hep G2 cells.Cell viability gradually decreased after treatment with sodium selenite within the concentration range of 10-50 microM. Low (10 mM) selenite has shown a high-percentage laddering pattern compared to the high (25 microM) cytotoxic selenium concentration in agarose gel electrophoresis. G2/M-phase enrichment was also concentration dependent. The most consistent transmission electron microscopic finding was the existence of large lysosomes. Based on these data, we hypothesize that sodium selenite predominantly shows its apoptotic effect over hydrogen selenite accumulation.

T cell subpopulations and IL-2R in vitiligo.

Immunological alterations have been implicated in the etiopathogenesis of vitiligo. The aim of this study was to determine peripheral lymphocyte subpopulations and interleukin-2 receptor (IL-2R) in patients with vitiligo. Forty-five vitiligo patients (24 female, 21 male) and 34 healthy controls (11 female, 23 male) were included into the study. Eight (17.8%) of the patients had the segmental type, and 37 (82.2%) had generalized vitiligo. The disease was active in 25 (55.6%) patients; the other 20 (44.4%) patients had static vitiligo. Flow cytometry was used to determine the percentages of total T-lymphocytes, B-lymphocytes, helper/inducer T cells, suppressor/cytotoxic T cells, natural killer (NK) cells, activated T cells and interleukin-2 receptor (IL-2R) with the use of CD3, CD19, CD4, CD8, CD16, HLA-DR and CD25 monoclonal antibodies, respectively. The mean value of helper T cells showed a significant difference (p=0.01) between the two groups with the value being 32.5% in patients and 38.1% in control subjects. CD4/CD8 was significantly lower in vitiligo patients (p=0.04). There was also a statistically significant difference in the mean percentage of activated T cells between vitiligo patients and control subjects (4.7 and 8.1, respectively; p=0.001). No statistically significant differences were found when the values were compared between segmental and generalized vitiligo patients, or between active and static cases. In conclusion, T helper/inducer cells, CD4/CD8 ratio and activated (HLA-DR+) T cells are decreased in vitiligo patients, suggesting a role for changes in cellular immunity.

Effect of portal venous injection of donor spleen cells on skin allograft survival in rat.

BACKGROUND & OBJECTIVES: Pretransplantation injection of donor lymphohaemopoetic cells via portal venous route has been shown to improve allograft survival in mice. In the present study, the effect of perioperative portal venous administration of donor splenocytes on skin graft survival was investigated in comparison with intravenous administration of spleen cells in Swiss albino rat skin transplant model. METHODS: Using a single-donor survival study, skin allograft recipients received either no treatment, a single transfusion of donor spleen cells via portal vein or a single transfusion of donor splenocytes into vena cava. Spleen cell transfusion consisted 25x10(6) viable cells in a volume of 1ml given just before skin grafting. Skin graft survival was assessed by macroscopic appearance. Rejection was defined as the first day on which the entire surface of the graft was necrotic. Histologically necrosis, increased connective tissue, vascularity and polymorphonuclear leucocyte (PNL) infiltration were evaluated under light microscopy. RESULTS: In this survival study of skin allografts, with the injection of viable spleen cells into portal vein concomitant to skin grafting, significant prolongation of mean allograft survival was induced (20.3 days), compared with untreated recipients (6.5 days, P<0.001). In the histopathologic evaluation, less PNL infiltration, necrosis, increased vascularity and connective tissue repair were observed in vena porta group with no statistical significance. INTERPRETATION & CONCLUSION: It may be possible to develop protocols to induce transplantation tolerance based on the historical concept of donor specific antigen administration. However, it appears that donor spleen cell transfusion alone is not sufficient to prevent graft rejection. Thus, more efficient combination treatments are required to induce a state of durable tolerance.

Fundamental principals of tumor necrosis factor-alpha gene therapy approach and implications for patients with lung carcinoma.

Apoptosis, known as programmed cell death, is defined as a cell's preferred form of death under hectic conditions through genetically conserved and complex pathways. There is a decisive balance between stimulatory and inhibitory signaling pathways to maintain homeostasis in cells. In order to shift the balance towards apoptosis, the modulation of both apoptotic and anti-apoptotic pathways represents an attractive target for cancer therapeutics. Currently, chemotherapy and radiotherapy are among the most commonly used treatment modalities against lung cancer. Tumor suppressor gene, p53, is required in order for both of these treatment methods to work as anti-tumor agents. As a result, tumors lacking p53 display resistance to both chemotherapy and radiotherapy. However, death ligands induce apoptosis regardless of p53 status of cells. Thus, these methods constitute a complementary therapeutic approach to currently employed conventional treatment modalities. At present, death ligands are being evaluated as potential cancer therapeutic agents. Since resistance to tumor necrosis factor (TNF)-alpha-mediated apoptosis represented an obstacle for the treatment of patients with lung carcinoma in the earlier attempts, an extensive research was recently initiated to understand molecular mechanism of TNF-alpha signaling. NF-kappaB transcription factors have been demonstrated to modulate the apoptotic program, mostly as blockers of apoptosis in different cell types. In this review, we concentrate on the current progress in the understanding of TNF-alpha-mediated apoptosis for lung carcinoma. Representative models of NF-kappaB-inhibiting gene therapy strategies from various labs including ours are also provided as examples of up-to-date approaches to defeat TNF resistance. In order to give the reader better understanding and appreciation of such approaches, previously unpublished in vivo assays are also incorporated into this review. Current progress in clinical trials using adenovirus-mediated delivery of TNF-alpha is also discussed.

A patient with hyper-IgD syndrome in Antalya, Turkey.

Hyper-IgD syndrome is a periodic fever syndrome that presents with recurrent episodes of high fever accompanied by lymphadenopathy, abdominal distress, arthralgias or arthritis, headache and skin lesions. The diagnosis is based on clinical grounds and elevated serum IgD levels (>100 U/ml), but requires a high index of suspicion, and a mevalonate kinase enzyme defect. Most patients are from western Europe but there are others identified in other countries. We describe a 17-year-old patient who had been followed with the diagnosis of familial Mediterranean fever for a long time before she was diagnosed with hyper-IgD syndrome.

Characterization of the cellular response during apoptosis induction in cadmium-treated Hep G2 human hepatoma cells.

Cadmium is a toxic transition heavy metal of continuing occupational and environmental concern, with a wide variety of adverse effects on regulation of gene expression and cellular signal transduction pathways. Injury to cells by cadmium leads to a complex series of events that can culminate in the death of the cell. It has been reported that cadmium induces apoptosis in many cell lines. However, the morphological characteristics leading to apoptosis or subsequent regeneration in cells exposed to cadmium have not been clarified. We evaluated whether human hepatoma cells maintained in culture undergo apoptosis when exposed to cadmium. Cytotoxic activity of cadmium on Hep G2 cells determined using 3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide assay. A DNA ladder assay was performed by electrophoresis. Cell cycle analysis was quantified by flow cytometry. Nuclear morphology was studied by fluorescence microscopy after staining with propidium iodide and Hoechst 33342. Morphologic alterations in culture hepatocytes treated with CdCl2 were observed by transmission electron microscopy. We have demonstrated that apoptosis is a major mode of elimination of damaged HepG2 cells in cadmium toxicity and it precedes necrosis.