Protective role of cardiac progenitor cell-derived-exosomes in a new human model of ageing-induced cardiac dysfunction

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Velux Stiftung

Background

Ageing of cardiomyocytes (CM) involves structural and functional adverse remodelling that finally could result in heart failure (HF) insurgence, which incidence rise along with age (1). Current medical therapies for HF may not always be tolerated in elder patients(2). Having shown that cardiac progenitor cells (CPCs) secrete nanoparticles named exosomes (EXO) enriched of cardioprotective factors(3,4), we are exploring EXO’s capacity to ameliorate senescence-derived modification into CMs. However, human models of in vitro cardiac aging are currently missing(5).

Aim

This study exploits CMs derived from human induced pluripotent stem cells (hiPSCs) as an in vitro model for cardiac senescence, that will be used as platform to characterize mechanisms involved in cardiac ageing and to test protective effect of CPC-derived EXO.

Methods

Patient-derived CPCs were reprogrammed into hiPSCs and subsequently expanded and differentiated into cardiomyocytes (hiPSC-CMs). Senescence-like phenotype was induced by short exposure (3 hours) to doxorubicin (DOX) at sub-lethal concentration (0.2 µM), followed by washing and medium change. Following DOX exposure, cells were exposed to EXO, derived from the purification of conditioned culture media of CPCs using an ultracentrifugation-based isolation method and quantified and sized using a NTA counter. Senescence induction was highlighted by protein and gene expression analysis and senescence-associated b-galactosidase (SA-β-gal) assay.Electrical activity of hiPSC-CMs was evaluated recording extracellular field potentials through multi-microelectrode arrays (MEA) and by single cell patch clamp. Metabolic features were analysed with western blot, real time RT-PCR and specific biochemical assays.

Results

DOX treatment in hiPSC-CMs induced senescence, as confirmed by activation of p21 and p16 pathways and increasing of SA-β-gal staining as compared to untreated cells (CTR). Biochemical and gene expression analysis revealed an increased ROS production and a reduction in mitochondrial potential, which drives a strong decrease in the ATP/AMP ratios. Real Time PCR analysis reveal an increased transcription of molecules related to the senescence associated secretory phenotype in DOX-CMs. Moreover, DOX-CMs showed impaired Ca++ handling, prolonged multicellular QTc and single cell APD, with increased APD variability and delayed afterdepolarizations (DADs) incidence in comparison to CTR.

EXO treatment mitigated the senescent phenotype induced by DOX, as shown by a decreased ROS induction, higher mitochondrial potential which drives a restored ATP/AMP ratio. Furthermore, DOX-induced QTc prolongation was prevented by EXO treatment.

Conclusion

Our hiPSC-CMs based cellular model recapitulates the phenotype of aged CMs in terms of senescence markers, electrical and metabolic proprieties. CPC-derived EXOs limit age-related modifications, highlighting the cardioprotective role of small molecules released by EXO.

POS0765 IS THERE ANY DIFFERENCE IN THE CLINICAL FEATURES AND OUTCOMES OF PROLIFERATIVE AND NON-PROLIFERATIVE FORMS OF LUPUS NEPHRITIS PROVEN BY BIOPSY?

Background

Lupus nephritis (LN), which occurs in 60-70% of patients with systemic lupus erythematosus, is a major determinant of morbidity and mortality. There still are many uncertain aspects in clinical, pathological, and prognostic characteristics about LN.

Objectives

We aimed to compare clinical features, outcomes, and to define the predictive factors of complete renal response (CRR) in patients with proliferative and non-proliferative LN.

Methods

Patients with SLE followed between 2014 and 2020 at Hacettepe University Hospitals and who had a kidney biopsy were the subject of the study. One hundred and sixteen patients whose kidney biopsy reported as LN were evaluated retrospectively. Clinical features, laboratory values at the time of kidney biopsy, histopathological forms of LN, and renal response (complete or partial) were recorded. The predictive factors for CRR during the two-year follow-up after induction therapy were analyzed.

Results

Of 116 (93 females, 23 males) patients, 95 (81.9%) were in the proliferative (class III and IV) and 21 (18.1%) were in the non-proliferative group (class II and V). In the proliferative group, elevated basal creatinine, median daily proteinuria, anti-dsDNA positivity, low C3 and C4, the presence of active urinary sediment, and median renal SLE Disease Activity Index (SLEDAI) scores at the time of kidney biopsy were significantly higher than non-proliferative group. During the two-year follow-up after LN diagnosis, 70 patients achieved CRR and time-to-CRR was similar for the groups (p=0.64, log-rank). The Cox proportional hazards model showed that achieving CRR was associated with female gender [HR: 2.15 (1.19-3.89 95% CI), p=0.011], newly diagnosed SLE with renal biopsy [2.15 (1.26-3.67), p=0.005], hypertension [0.40 (0.27-0.94), p=0.032], eGFR increase [1.01 (1.00-1.01), p=0.046], and presence of active urinary sediment [0.46 (0.22-0.96), p=0.039].

Conclusion

Achieving CRR was similar in both the proliferative and non-proliferative LN patients although certain laboratory parameters differed at onset. Our results indicated the importance of kidney biopsy in the decision-making of treatment of SLE patients with renal involvement and that the defined factors associated with CRR achievement help to predict good renal response.

Table 1.

Demographic, clinical characteristics, and outcomes of the patients with LN

Variables*All patientsProliferative LNNon-Proliferative LNpn=116n=95n=21Age at SLE diagnosis, years18.3 (16)19.2 (15)16 (16)0.32Sex, female93 (80.2)75 (78.9)18 (85.7)0.48Age at kidney biopsy, years21 (17.7)22 (17)18 (15)0.19Patients newly diagnosed SLE with renal biopsy65 (56)53 (55.8)12 (57.1)0.91Follow-up time for LN, years5.5 (8)5.1 (8.2)6.2 (5.1)0.80SLE disease duration8 (8.7)8.1 (9.6)7.9 (7.3)0.53Hypertension31 (26.7)26 (27.4)5 (23.8)0.74Laboratory values on the kidney biopsy Creatinine level (mg/dL)0.7 (0.5)0.8 (0.5)0.56 (0.1)0.006 Creatinine > UNL37 (32.5)34 (36.6)3 (14.3)0.04 eGFR (mL/min/1.73m2)113 (54)107 (54)129 (45)0.04 Albumin (g/dL)3.3 (1.1)3.1 (1.2)3.5 (1)0.09 24-hour urine protein, gr/day2.3 (3.3)2.4 (3.6)0.9 (1.8)0.03 Anti-dsDNA positivity94 (81)80 (87.9)14 (70)0.04 Low C3 and C4 levels93 (80.2)81 (88)12 (57.1)0.001 Active urinary sediment91 (83.5)78 (89.8)12 (57.1)<0.001Renal SLEDAI12 (8)12 (8)4 (4)<0.001During the two-year follow-up after LN diagnosis Complete renal response70 (70.7)56 (70.9)14 (70)0.99 Partial renal response23 (23.2)17 (21.5)6 (30)0.64 No response6 (6.1)6 (7.6)0NA Relapse20 (21.5)15 (20.5)5 (25)0.84 ESRD4(4)4 (4.2)0NA Death3 (3)3 (3.2)0NA

* n (%), if otherwise specified; median (IQR) for numeric values

ESRD: End-stage renal disease, GFR: Glomerular filtration rate, LN: Lupus nephritis, SLE: Systemic lupus erythematosus, SLEDAI: Systemic Lupus Erythematosus Disease Activity Index; UNL: Upper normal limit

Figure 1.

Kaplan-Meier survival curve for complete renal response (CRR) achievement during the two-year follow-up according to the kidney biopsy results

Disclosure of Interests

None declared

Can the hydrogel form of sodium ascorbate be used to reverse compromised resin infiltrant penetration after bleaching?

Aims

The aim of this study was to investigate the effects of an antioxidant on the bleaching-induced reduction in the penetration depth of infiltrant resins.

Materials and Methods

White spot lesions (WSLs) were created on 105 bovine tooth samples, each measuring 6 × 4 × 4 mm. Five samples were randomly selected for the examination of lesion characteristics. The remaining 100 samples were then divided into four groups (n = 25). In Group I, the WSLs were treated with resin infiltration (RI) only. RI was performed on Group II immediately after bleaching. In Group III, an antioxidant was applied for 2 h after bleaching, and this was immediately followed by RI. The Group IV samples were treated with RI at the end of a 1-week waiting period after bleaching. The penetration depths were evaluated through confocal laser scanning microscopy.

Results

The lowest penetration rate, which was approximately 57%, was observed in Group II. This was followed by Group III (87%), Group IV (90%), and Group I (92%). Group II, in which the samples were infiltrated immediately after bleaching, had the lowest mean penetration percentage. All the bleached groups exhibited significantly lower penetration percentages than the nonbleached group (Group I) (P < 0.05). Antioxidant application increased the penetration significantly (P < 0.05).

Conclusion

Application of sodium ascorbate was found to reverse the reduced resin penetration depth and penetration percentages resulting from bleaching. The postponement of adhesive procedures after bleaching yielded similar results.

POS0255 IMPACT OF PLASMA EXCHANGE (PLEX) IN SEVERE ANCA-ASSOCIATED VASCULITIS (AAV): A REAL-LIFE DATA FROM A PROSPECTIVE COHORT

Background:

PEXIVAS was the largest clinical trial conducted on severe AAV patients and failed to demonstrate the contribution of PLEX on the prognosis of severe AAV. This data needs to be tested with real life experiences.

Objectives:

The aim of this study was to explore the effects of PLEX on the prognosis of severe AAV in a real-life cohort.

Methods:

Hacettepe University Vasculitis Research Center (HUVAC) prospective database was established in October 2014 by registering past and newly diagnosed patients. Baseline disease characteristics, treatments and survival status were recorded. For this study, patients with granulomatosis polyangiitis (GPA) and microscopic polyangiitis (MPA) who met the inclusion criteria of PEXIVAS trial [briefly; ANCA positive MPA or GPA patients with either severe renal involvement (necrotizing glomerulonephritis or active urinary sediment, and eGFR <50 ml/min) and/or severe pulmonary involvement (pulmonary hemorrhage due to active vasculitis)] at the disease onset were included. Patients were grouped whether they had PLEX or not. Demographic and disease-specific data and immunosuppressive agents used in induction phase were compared. Primary outcome was accepted as composite index of mortality or end-stage renal disease (ESRD) at the first year and at the final visit.

Results:

Of 145 GPA and MPA patients, 49 patients had inclusion criteria and distribution of patients were as GPA (n=38), MPA (n=8) or renal-limited (n=3). 16 (32.6%) patients had PLEX. Median number of plasma exchange cycles was 6.5 (min-max; 2-12). Although severe pulmonary [10 (62.5%) vs. 5 (15.2%), p=0.001] and combined severe renal+pulmonary involvements were more prevalent [9 (56.3%) vs. 4 (12.1%), p=0.001] and baseline creatinine levels were higher in PLEX (+) group, BVAS and FFS scores were similar (Table 1). Induction immunosuppressive regimens were comparable.

At first year evaluation, primary composite outcome was observed in 11 patients (3 deceased, 8 ESRD) of PLEX (+) group whereas in 12 patients (2 deceased, 10 ESRD) of PLEX (-) group (p = 0.03, log-rank). In multivariate analysis: combined renal+pulmonary involvements (aOR: 6.5 [1.1-37.9]) and serum creatinine (for 1 mg/dl increment) (aOR: 1.3 [1.1-1.7]) were associated with primary outcome. In this model, having plasma exchange was not associated with a favorable outcome.

At the end of median follow-up [40.7 (1.2-170.3) months], outcome was observed in 12 patients (9 deceased, 3 ESRD) of PLEX (+) group and in 13 patients (6 deceased, 7 ESRD) of PLEX (-) group (p < 0.001, log-rank). In multivariate analysis: having plasma exchange (HR: 3.5 [1.4-8.5]) and combined renal+pulmonary involvements (HR: 2.4 [1.05-5.8]) were found as the predictors of primary composite outcome. In the figure 1, comparison of primary outcome according to FFS and plasma exchange status was given.

Conclusion:

In real-life plasma exchange did not have a positive impact on the composite index of mortality and ESRD, similar to PEXIVAS trial. Presence of combined severe renal and pulmonary involvement was the predictor of worse outcome at 1-year and overall follow-up.

Table 1.

Comparison of disease characteristics and composite indexes of patients

PLEX (+)(n=16)PLEX(-)(n=33)GPA/MPA/Renal-limited (n)12/3/126/5/2Female, n(%)8 (50.0)13 (39.4)Age at diagnosis, months (med,min-max)54.5 (18.8-77.8)55.6 (18.1-86.3)MPO-ANCA / PR3-ANCA (n)5 / 1116 / 17Follow-up duration, months (med, min-max)16.6 (1.2-116.5)50.5 (2.2-170.0)BVAS at diagnosis, (med, min-max)23 (14-37)23 (8-33)FFS ≥ 2 (n,%) (N=45)23 (85.7)26 (83.9)Creatinine (mg/dl) at diagnosis† (med,min-max)8.1 (4.1-8.9)3.1 (1.8-6.2)CRP (mg/dl) at diagnosis (med,min-max)21.8 (15.0-29.0)11.5 (3.6-20.0)Immunosuppressive (induction) (n,%) -Pulse steroid14 (87.5)29 (87.9) -Rituximab1 (6.3)3 (9.1) -Cyclophosphamide12 (75.0)28 (84.8)

†p = 0.005

Figure 1.

Comparison of primary outcome according to FFS and plasma exchange status

Disclosure of Interests:

None declared

AB0347 RENAL BIOPSY IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: IS IT ONLY LUPUS NEPHRITIS?

Background:

Renal biopsy is a cornerstone in the diagnosis and management of renal involvement in patients with systemic lupus erythematosus (SLE). However, non-lupus nephritis has been also observed in SLE patients with renal disease (1).

Objectives:

The aim of this study was to draw attention to the causes of non-lupus nephritis in SLE patients with kidney biopsy.

Methods:

This retrospective, descriptive study included 139 SLE patients who had at least one kidney biopsy between 2001 and 2020. All patients had fulfilled the SLICC or EULAR/ACR criteria for SLE. According to the pathology report results, 116 of the patients were diagnosed with lupus nephritis (LN), 18 patients had non-lupus nephritis, 2 biopsies were normal, and 3 biopsies were insufficient. Demographics, SLE disease duration, and renal biopsy diagnosis were derived from our hospital medical records.

Results:

Of the 23 patients (female:18/male:5), the mean age at the SLE diagnosis was 30.5 years and the median SLE disease duration was 8.5 (11.6) years. Pathologic report findings were compatible with focal segmental glomerulosclerosis in 6 patients, membranous nephropathy with no cellular proliferation and inflammation in 4 patients, thrombotic microangiopathy in 3 patients, IgM nephropathy in 2 patients, tubulointerstitial nephritis in 2 patients, and proliferative glomerulonephritis with monoclonal IgG deposits in one patient. There were no different for SLE manifestation in both gropus. LN vs other renal pathologies laboratory comparing as follow: ANA (+) ≥ 1:320 89 (76.7%) vs 14 (60.9%), APS antibodies 31 (33.7%) vs 8 (57.1), anti-Sm (+) 8 (11.8%) vs 1 (4.3%) were similar for LN and other renal pathologies, but anti-ds-DNA positivity 94 (84.7%) vs 10 (50%), median ds-DNA level 421 (591) vs 150 (340) and low level of C3 and C4 were more frequent in LN (p<0.001; p=0.005; p<0.001, respectively).In addition, the rate of active urinary sediment and renal SLEDAI score were significantly high in LN patients.

Conclusion:

Various renal lesions unrelated to lupus nephritis can be observed in SLE patients. Renal biopsy plays a critical role in identifying these lesions, which may have prognostic and therapeutic implications distinctive from those of lupus nephritis. Also, anti ds-DNA positivity/level, low C3 and C4, active urinary sediment and renal SLEDAI scores may give us some clues in terms of renal pathology for SLE patients. Moreover, almost half of the patients without LN in renal biopsy have anti ds-DNA positivity.

References:

[1]Howell DN. Renal biopsy in patients with systemic lupus erythematosus: Not just lupus glomerulonephritis! Ultrastruct Pathol. 2017 Mar-Apr;41(2):135-146.

Table 1.

Demographic, clinical characteristics and results of patients with and without lupus nephritis

Variables*Lupus nephritis(N=116)Other pathologies(N=23)PAge at the SLE diagnosis, years22.5±13.130.5±14.50.006Sex, female93 (80.2)18 (78.3)0.83SLE disease duration8 (8.7)8.5 (11.6)0.27Manifestation of SLE-Musculoscletal75 (66.4)14 (63.6)0.8-Mucocutaneous60 (52.6)9 (40.9)0.31-Hematologic47 (40.9)10 (43.5)0.49-Serosal26 (23.2)4 (17.4)0.54-Neurological6 (5.3)1 (4.3)0.85Laboratory values for kidney biopsy-Creatinine level (mg/dL)0.7 (0.5)0.9 (0.6)0.17-GFR (ml/min)110 (67)77 (65)0.06-24-hour urine protein≥ 1 gr/day72 (71.3)17 (77.3)0.63≥ 3 gr/day36 (35.6)11 (50)0.23-Active urinary sediment91 (83.5)6 (27.3)<0.001Renal SLEDAI at the biopsy12 (8)4 (4)<0.001End-stage renal disease13 (11.2)2 (8.7)0.72Renal transplantation5 (4.3)1 (4.3)0.99Exitus8 (7)1 (4.3)0.99

*n (%), if otherwise specified. Med (IQR) for numerical data excluding age; mean ± SD for age.

GFR: Glomerular filtration rate, LN: Lupus nephritis, SLEDAI: Systemic lupus erythematosus disease activity index

Disclosure of Interests:

None declared

POS0793 PREDICTORS OF END STAGE RENAL DISEASE IN THE RENAL BIOPSY PROVEN LUPUS NEPHRITIS

Background:

Although focusing on the proliferative form of lupus nephritis (LN), recent reports also highlight the importance of recognizing and treating non-proliferative forms of LN.

Objectives:

In this study, we aimed to compare the clinical features and outcomes between proliferative and non-proliferative LN and to investigate the predictor factors of end stage renal disease (ESRD).

Methods:

This retrospective study included 139 SLE patients who had at least one kidney biopsy between 2001 and 2020. 116 patients were diagnosed as LN. Biopsy findings had been classified according to the International Society of Nephrology and the Renal Pathology Society (ISN/RPS) classification. Demographics, disease involvements, laboratory values, treatment regimens, and outcomes in LN course were compared according to the proliferative and non-proliferative LN. Complete renal response within first 24 months was defined as ACR response criteria. Factors predicting the ESRD were analysed by the logistic regression analysis.

Results:

A total of 116 lupus nephritis patients were categorised class 3 (n=17, 14.7%) or 4 (n=77, 66.4%) as proliferative LN and class 2 (n=9, 7.8%) or 5 (n=13, 11.2%) as non-proliferative LN. Of these patients, 80.2% was female. Mean age at the SLE diagnosis and SLE manifestations were similar for both group. ANA (+) ≥ 1:320, ds-DNA level, APS antibodies, anti-Sm (+) were similar for proliferative and non-proliferative LN, but ds DNA positivity and low level of C3 and C4 were more frequent in proliferative LN. LN duration was similar. Median renal SLEDAI scores were higher in proliferative LN group. Induction treatment regimens included pulse steroid 72.3%, CyC 51.8%, MMF 24.6%, Rtx 6.1%, CsA 4.4%, and plasma exchange 12.9%. ESRD, renal transplantation and exitus were major complications of LN. Predictors of ESRD were duration of lupus nephritis (OR 1.32 [1.09-1.61]; 95% CI), decrease in GFR at the biopsy time (OR 0.97 [0.95-0.99]; 95% CI), and being in complete renal response within 24 months (OR 21.07 [2.28-194.36]; 95% CI).

Conclusion:

Unfortunately, LN patients still have worse outcomes, such as high ESRD rate, regarding to current effective immunosuppressive treatment regimens. Although patients’ number were not enough for conclusion, interestingly, worse outcomes were not related with proliferative or non-proliferative LN. Complete remission within 24 months was most relevant good prognostic factor, and clinicians should be kept in mind to these windows of opportunity period.

Table 1.

Demographic, clinical characteristics, and outcomes of the patients with lupus nephritis

Variables*All patients (n=116)Class 3 or 4 LN (n=94)Class 2 or 5 LN (n=22)pAge at the SLE diagnosis, years22.5±13.123±13.320.3±140.32Sex, female93 (80.2)74 (78.7)19 (86.4)0.42SLE disease duration8 (8.7)8 (9.7)8.3 (7.5)0.66Lupus nephritis at diagnosis time67 (58.8)54 (58.7)13 (59.1)0.97Manifestation of SLE-Musculoscletal75 (66.4)63 (68.5)12 (57.1)0.32-Mucocutaneous60 (52.6)50 (54.3)10 (45.5)0.45-Hematologic47 (40.9)38 (40.4)9 (42.9)0.83-Serosal26 (23.2)21 (23.1)5 (23.8)0.94-Neurological6 (5.3)5 (5.4)1 (4.8)0.91Laboratory values for kidney biopsy-Creatinine level (mg/dL)0.7 (0.5)0.8 (0.5)0.6 (0.2)0.01-GFR (ml/min)110 (67)92 (55)145 (59)0.03-≥ 60 ml/min79 (79.8)63 (77.8)16 (88.9)-30-59 ml/min8 (8.1)7 (8.6)1 (5.6)0.55-< 30 ml/min12 (12.1)11 (13.6)1 (5.6)-24-hour urine protein≥ 1 gr/day72 (71.3)62 (76.5)10 (52.6)0.04≥ 3 gr/day36 (35.6)32 (39)4 (21.1)0.14-Active urinary sediment91 (83.5)78 (89.7)13 (59.1)0.001Renal SLEDAI at the biopsy12 (8)12 (8)8 (8)0.001Lupus nephritis duration (years)5.5 (8)5.1 (8.3)6.4 (4.8)0.73Complete renal response within 24 months69 (71.1)55 (72.4)14 (66.7)0.61End-stage renal disease13 (11.2)11 (11.7)2 (9.1)0.72Renal transplantation5 (4.3)4 (4.3)1 (4.5)0.95Exitus8 (7)7 (7.5)1 (4.5)0.62

*n (%), if otherwise specified. Med (IQR) for numerical data excluding age; mean ± SD for age.

GFR: Glomerular filtration rate, LN: Lupus nephritis, SLEDAI: Systemic lupus erythematosus disease activity index

Disclosure of Interests:

None declared

SERCA2a stimulation by istaroxime improves intracellular Ca2+ handling and diastolic dysfunction in a model of diabetic cardiomyopathy

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by CVie Therapeutics Limited (Taipei, Taiwan) and Windtree Therapeutics (Warrington, USA)

Diabetic cardiomyopathy is a multifactorial disease characterized by an early onset of diastolic dysfunction (DD) that precedes the development of systolic impairment. Mechanisms that can restore cardiac relaxation improving intracellular Ca2+ dynamics represent a promising therapeutic approach for cardiovascular diseases associated to DD. Istaroxime has the double property to accelerate Ca2+ uptake into sarcoplasmic reticulum (SR) through the SR Ca2+ pump (SERCA2a) stimulation and to inhibit Na+/K+ ATPase (NKA). The project aims to characterize istaroxime effects at a concentration (100 nM) marginally affecting NKA, in order to highlight its effects dependent on the stimulation of SERCA2a in a model of mild diabetes.

Streptozotocin (STZ) treated diabetic rats were studied at 9 weeks after STZ injection in comparison to controls (CTR). Istaroxime effects were evaluated in vivo and in left ventricular (LV) preparations. STZ animals showed 1) marked DD not associated to cardiac fibrosis, 2) LV mass reduction associated to reduced LV cell dimension and T-tubules loss, 3) reduced LV SERCA2 protein level and activity and 4) slower SR Ca2+ uptake rate, 5) LV action potential (AP) prolongation and increased short-term variability (STV) of AP duration, 6) increased diastolic Ca2+, 7) unaltered SR Ca2+ content and stability in intact cells. Acute istaroxime infusion (0.11 mg/kg/min for 15 min) reduced DD in STZ rats. Accordingly, in STZ myocytes istaroxime (100 nM) stimulated SERCA2a activity and blunted STZ-induced abnormalities in LV Ca2+ dynamics. In CTR myocytes, istaroxime increased diastolic Ca2+ level due to NKA blockade albeit minimal, while its effects on SERCA2a were almost absent.

SERCA2a stimulation by istaroxime improved STZ-induced DD and intracellular Ca2+ handling anomalies. Thus, SERCA2a stimulation can be considered a promising therapeutic approach for DD treatment. Abstract Figure.

Does pendimethalin develop in pancreatic cancer induced inflammation?

Pendimethalin, one of the dinitroaniline group herbicides, is applied for controlling weeds in cereals, legumes and vegetable crops, and has been classified as possible human carcinogen. It is indicated that pendimethalin should arise risks of developing some cancer types; however, there is no data on the effects of pendimethalin on pancreatic cancer-induced inflammation. Injuries resulting from by acute pancreatitis attacks and inflammation are significant factors in the development of pancreatic cancer. Therefore, we investigated whether pendimethalin triggers inflammation as a mechanism of pancreatic cancer development. Parameters related to pancreatic activation, oxidative stress, and inflammation were measured in the human pancreatic (PANC-1) cell line. In the range of 0-100 μM, the levels of chymotrypsin decreased. It should be indicated that the reason for the decrease in chymotrypsin may be the high rates of cell death (20%) observed in the high concentration levels. We observed that pendimethalin significantly induced oxidative damage, while levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) did not change. The obtained results may draw attention to the usage and possible toxic effect of pendimethalin due to oxidative damage induction; however, detailed inflammation mechanisms and other cancer pathways should be investigated.

Does allograft size really matter in the long-term outcome of living donor kidney transplantation?

BACKGROUND

Increased allograft mass in living donor kidney transplantation has been recognized as a predictor factor of better short-term allograft function. We evaluated whether donor kidney volume adjusted for recipient body weight is associated with long-term allograft function in living donor kidney transplantation.

METHODS

We analyzed 67 living donors and their recipients who underwent transplantation between 2003 and 2007. Estimated glomerular filtration rate (eGFR) and serum creatinine levels at 1, 2, 3, 4, and 5 years post-transplantation were recorded for all recipients. Transplanted kidney volumes were measured using 3-D helical computed tomography scanning. A transplant kidney volume-recipient body weight (Vol/Wt) ratio was calculated for each donor-recipient pair. The subjects were divided into tertiles according to Vol/Wt ratios: low (<2.16), medium (2.16-2.88), and high (>2.88).

RESULTS

Vol/Wt ratio significantly correlated with recipient eGFR and serum creatinine levels at 1, 2, 3, and 4 years post-transplantation (r = .48, P < .0001; r = .46, P < .0001; r = .47, P < .0001; r = .26, P = .037, respectively, for eGFR; r = -.53, P < .0001; r = -.50, P < .0001; r = -.44, P < .0001; r = -.37, P = .003, respectively, for serum creatinine) but not at 5 years (r = .12, P = .406 for eGFR; r = -.21, P = .110 for serum creatinine). Whereas recipient eGFR increased significantly in a graded fashion among low to high Vol/Wt ratio groups during 1 to 3 years post-transplantation, there was no difference in eGFR values between Vol/Wt ratio groups at 4 and 5 years (P = .21 and .71, respectively).

CONCLUSION

Vol/Wt ratio is not associated with long-term allograft function in living donor kidney transplantation.

Endothelial dysfunction in renal transplant recipients: role of vitamin D and fibroblast growth factor-23

BACKGROUND

Endothelial dysfunction can be detected at early stages of chronic kidney disease. Although endothelial functions improve after successful renal transplantation, renal transplant recipients have still worse endothelial functions compared to healthy subjects. Vitamin D deficiency and high fibroblast growth factor-23 (FGF-23) levels may have a role on endothelial dysfunction in chronic kidney disease patients. The aim of this study is to investigate the association between endothelial functions, vitamin D, and FGF-23 levels in renal transplant recipients.

METHODS

One hundred nine renal transplant recipients (71 male, 38 female) underwent brachial flow-mediated dilatation (FMD), serum 25-OH vitamin D, and FGF-23 level measurements. Vitamin D and FGF-23 levels were compared between patients with normal and abnormal endothelial functions. Correlations between FMD, vitamin D, and FGF-23 were also investigated.

RESULTS

Endothelial functions were abnormal in 72.5% of the patients. Prevalence of vitamin D deficiency was 80.7%. Vitamin D levels were significantly lower in patients with endothelial dysfunction compared to patients with normal endothelial functions (12.6 ± 6.6 μg/L vs 17.3 ± 10.0 μg/L respectively, P = .02). FGF-23 levels were not different between the two groups. 25-OH vitamin D levels had a significant positive correlation with amount of FMD (r = 0.218 and P = .02) and were an independent predictor of FMD after adjusting for potential confounding factors including age, transplantation duration, body mass index, mean blood pressure, glomerular filtration rate, proteinuria, hemoglobin, and FGF-23 in multivariate regression analysis (beta = 0.194, P = .04). FGF-23 levels were not predictive of FMD in this model (beta: -0.125, P = .197) CONCLUSION: Vitamin D deficiency is associated with endothelial dysfunction in renal transplant recipients. Further clinical and experimental studies are necessary to define a causal relationship between the parameters, discover the potential mechanisms, and observe the effect of vitamin D replacement on endothelial functions in renal transplant recipients.

Proton pump inhibitor omeprazole use is associated with low bone mineral density in maintenance haemodialysis patients

OBJECTIVE

Limited studies have shown that proton pump inhibitor (PPI) therapy may decrease bone density or insoluble calcium reabsorption through induction of hypochlorhydria. However, PPI therapy may also reduce bone resorption via inhibition of osteoclastic vacuolar proton pumps. The aim of this study was to determine whether the opposing effects of PPI therapy may cause clinically important alterations in bone mineral densitometry (BMD) parameters in maintenance haemodialysis patients.

METHODS

Sixty-eight maintenance haemodialysis patients were enrolled in this study. Patients were classified into two groups involving users of PPI therapy (omeprazole 20 mg/day, group 1, n = 36 patients) and non-users of acid suppression drugs (group 2, n = 32 patients). Patients had radius, hip and spine BMD assessed by dual-energy X-ray absorptiometry.

RESULTS

The mean duration of PPI therapy with omeprazole was 27 +/- 5 months. The users of PPI therapy had lower values of bone mineral density and T-scores at the anatomical regions than non-users of acid suppression drugs. Serum calcium and phosphate levels, calcium-phosphate product and serum intact parathormone levels and the ratio of users of vitamin D therapy were similar among groups. A mutivariable adjusted odds ratio for lower bone density associated with more than 18 months of omeprazole, when all the potential confounders were considered, was 1.31 in the proximal radius, 0.982 in the femur neck, 0.939 in the trochanter and 1.192 in the lumbal spine.

CONCLUSION

The present data suggest that PPI therapy should be cautiously prescribed in maintenance haemodialysis patients, especially with lower BMD values.

The analysis of interleukin-1 receptor antagonist and interleukin-1beta gene polymorphisms in Turkish FMF patients: do they predispose to secondary amyloidosis?

OBJECTIVE

Amyloid development in familial Mediterranean fever (FMF) patients is associated with acute phase response and the acute phase reactant serum amyloid A which is induced by IL-1Beta. Its concentration can increase to more than 1000 fold during inflammation. In view of the inflammatory nature of FMF disease we have investigated whether IL-1Beta and IL-1 receptor antagonist gene polymorphisms may be involved in amyloid development in FMF patients.

METHODS

Ninety-nine FMF patients without amyloidosis; 54 FMF patients with amyloidosis and 60 healthy controls samples were genotyped for IL-1Beta-511 (C/T) and IL-1Beta+3953 (C/T) polymorphisms using PCR-RFLP and for IL-1Ra VNTR polymorphism using PCR.

RESULTS

The allele and genotype frequencies of IL-1Beta-511 (C/T), IL-1Beta+3953 (C/T) and IL-1Ra VNTR polymorphisms in FMF patients with and without amyloidosis were all compared with those in controls. There were no significant differences between FMF patients with and without amyloidosis and healthy control samples for these polymorphisms (all P-values are >0.05). These polymorphisms were not associated with M694V mutation in FMF patients with and without amyloidosis.

CONCLUSION

IL-1Beta-511 (C/T), IL-1Beta+3953 (C/T) and IL-1Ra VNTR polymorphisms are not associated with the development of amyloid in FMF patients.

Gingival health status in renal transplant recipients: relationship between systemic inflammation and atherosclerosis

Cardiovascular disease (CVD) is the leading cause of mortality in renal transplant recipients (RTR). Systemic and periodontal inflammation has been suggested to have a possible role in the development of atherosclerosis. In the present study, we aimed to investigate the relationship between gingival health status, inflammation and atherosclerosis in RTRs. Eighty-three RTR (50 male, 33 female) were enrolled in the study. Routine biochemical analyses, serum lipoproteins, C-reactive protein, fibrinogen, homocystein, parathyroid hormone (PTH) and cyclosporin A (CsA) trough levels were studied. All patients had 24-h ambulatory blood pressure monitoring and B-mode ultrasound of the common carotid arteries. Gingival status was evaluated by the Löe and Silness gingival index (GI). Mean GI value was 2.3 +/- 0.5. Fifty patients (60.3%) had GI value >or= 2.1 (severe gingivitis; group A). Thirty-three patients (39.7%) had GI value < 2.1 (no or moderate gingivitis; group B). Age, carotid intima-media thickness (CIMT) and mean time on dialysis before transplantation were significantly higher in group A than in B. Systemic inflammation markers were not different between group A and group B. Mean CIMT was positively correlated with GI (r = 0.425; p = 0.001) and negatively correlated with high-density lipoprotein cholesterol (r = -0.256; p = 0.023). After the correction for confounding variables, mean CIMT was still significantly correlated with GI (r = 0.376, p = 0.02). In RTR, gingival inflammation seems to be associated with CIMT in the absence of systemic inflammation. Thus, gingivitis may, in part, play a role in the development of systemic atherosclerosis without causing any aggravation in systemic inflammatory response.

The role of proinflammatory cytokine gene polymorphisms for development of insulin resistance after renal transplantation

BACKGROUND

Insulin resistance, a frequent prediabetic metabolic complication after renal transplantation, is generally linked to immunosuppressive drugs including corticosteroids, cyclosporine (CsA) or tacrolimus, as well as to age, cadaveric donors and ethnic factors. Cytokines are known to be inflammation modulatory substances that contribute to metabolic derangements after transplantation. The present study investigated the effects of cytokine gene polymorphisms on insulin resistance in renal transplant recipients.

PATIENTS AND METHODS

Sixty-one renal transplant recipients (37 men, 24 women; mean age: 39.3 +/- 10.8 years) who attended regular clinical visits without a known history of diabetes were enrolled in the study. All patients were on a regimen of steroid, CsA, and mycophenolate mofetil. Venous blood samples were collected for biochemical analyses after an overnight fast at 08:00 pm. CsA trough levels, C-reactive protein, and fibrinogen were also estimated. Additional 10 mL of blood was withdrawn into an ethylenediamine tetraacetic acid-containing tube to determine cytokine genotypes (tumor necrosis factor-alpha [TNF-alpha] -238 G/A, transforming growth factor-beta [TGF-beta] codon 10 -869 T/C). Insulin resistance was calculated by the homeostasis model assessment (HOMA) method using the values of fasting blood glucose (FBG) and insulin levels. Anthropometric indices as well as body height, weight, waist and hip circumferences were measured simultaneously to calculate body mass index (kg/m2) and waist-to-hip ratio. Impaired fasting glucose (IFG) was described as an FBG > or = 110 but < 126 mg/dL.

RESULTS

IFG was detected in 27.9% of this study group. The HOMA index was significantly higher among patients with IFG compared with normal FBG (NoGT) (6.3 +/- 4.5 vs 3.7 +/- 1.5; P = .01). Neither FBG and insulin nor HOMA values correlated with antrophometric, metabolic, or inflammatory parameters. Cytokine genotype allele frequencies, age, sex, immunosuppressive and antihypertensive drug type and doses, CsA trough levels, and donor source (cadaveric/living) were similar for patients with IFG and NoGT. Mutant allele carrier genotypes (AA + GA) for TNF-alpha -238 G/A showed higher fasting insulin (14.0 +/- 7.9 vs 34.1 +/- 17.7 microIU/mL; P = .04) and HOMA (4.01 +/- 2.01 vs 7.95 +/- 5.44; P = .002) levels than GG homozygote subjects. FBG, HOMA, and other metabolic and anthropometric indices were similar between TGF-beta codon 10 -869 T/C genotypes. The daily dose of steroid (mg/d) and A allele frequency for TNF-alpha -238 G/A genotype were significant predictors of HOMA index in linear regression analysis.

CONCLUSION

The present study revealed that beside the daily dose of steroids, TNF-alpha -238 G/A genotype may contribute to insulin resistance in renal transplant recipients. Further investigations may highlight the effects of cytokine gene heterogenity on insulin resistance in those patients.

Septic arthritis caused by nocardia asteroides in a renal transplant recipient

Although articular complications are common following renal transplantation, septic arthritis is not frequent. Previous bacterial infection in an another site is a consistent finding and the knee is the most often affected joint. We present a 30-year-old female renal transplant recipient with recurrent pulmonary infiltrates preceding septic arthritis of her left knee. Cultures of the aspirated synovial fluid yielded a gram-positive, rod-shaped bacterium later identified as Nocardia asteroides. The patient was treated with oral trimethoprim-sulfamethoxazole without any side effect. Nocardia is a rare but serious cause of infection in renal transplant recipients but there is no well-known predisposing factor. Recently mycophenolate mofetil has been implicated as a factor associated with Nocardia infections. Prolonged courses of treatment with sulphonamides are recommended.

Prediction of renal allograft function with early Doppler ultrasonography

INTRODUCTION

Doppler ultrasonography (USG) is an useful, noninvasive diagnostic tool for the management and follow-up of the transplanted kidney. However, it is believed that the value of Doppler USG is limited to discrimination of acute rejection episodes. We tested whether early Doppler USG findings were predictive of 1-month and 1-year allograft functions in noncomplicated renal transplant recipients (RTRs).

PATIENTS AND METHODS

Resistive index (RI) and pulsatile index (PI) values obtained by doppler USG within the first week of transplantation were correlated with allograft function at 1 month and 1 year in 45 (10 women, 35 men, mean age: 27 years) noncomplicated cases. Patients with complications during the first posttransplant year were not included.

RESULTS

There was a negative correlation between both RI and PI with creatinine clearance values at 1 month and at 1 year posttransplant. There was a significant decline in allograft function among cases with either RI > or = 0.7 or PI > or = 1.1. Patients with impaired allograft function have higher RI and PI values.

CONCLUSION

Renal allograft survival is influenced by many factors. However, no reliable simple parameter has been identified to predict long-term outcome. Doppler USG performed during the early transplantation period with calculation of RI and PI may have a predictive value to forecast early and long-term outcomes of noncomplicated kidney transplants.

Pure red cell aplasia preceding malignant lymphoma in a renal transplant patient

Malignant disorders are one of the major causes of morbidity and mortality in transplant patients. We present herein a renal transplant recipient with malignant lymphoma which preceded by pure red cell aplasia (PRCA). Acquired PRCA is a rare hematologic disorder in renal transplant recipients. It has been associated with a variety of disorders of immunologic dysfunction and neoplasms, exposure to drugs and toxins, infectious diseases, pregnancy and severe nutritional deficiency. This is the first case with PRCA preceding the malign lymphoma in a renal transplant patient. Treatment of lymphoma and lymphoma-related humoral and cellular changes or other undefined effects that may be related to therapy may be responsible of the resolving of PRCA in this patient. In this regard, renal transplant patients with acquired PRCA, must be closely followed for an underlying neoplastic disorder.

Mycoflora of hazelnut (Corylus avellana L.) and aflatoxin content in hazelnut kernels artificially infected with Aspergillus parasiticus

In this research, 30 hazelnut samples were used to determine their internal mould populations and their aflatoxin contents. The results showed that Aspergillus was the most common genus in the experimental samples (96.6% of all samples). Thirty-one% of isolates were classified as Aspergillus flavus and none of the samples contained aflatoxins. In the second part of the experiment, the kernels were inoculated with conidia of Aspergillus parasiticus and incubated at three different humidified conditions and two different temperatures for 45 days. Aflatoxin contents of the samples kept in 98% relative humidity and at 28 degrees C were higher (904.6 micrograms/kg) than that of the other samples. On the other hand, no aflatoxin was detected in the control samples that were not inoculated but kept at the same conditions.

Effect of ketanserin administration on intraocular pressure

PURPOSE

We evaluated the effect of oral single-dose (20 mg) ketanserin on intraocular pressure (IOP) in normotensive and hypertensive eyes.

METHODS

This study included 15 healthy volunteers and 16 patients with ocular hypertension. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, IOP and pupil diameter were recorded at baseline and at 1-hour intervals for 6 h, in addition, tonographic outflow facility was studied at the third hour after the administration of placebo or an oral single dose of 20 mg ketanserin given in a randomized double-blind crossover fashion. The alternative treatment was applied a week later.

RESULTS

In both groups, oral single-dose (20 mg) ketanserin significantly lowered IOP and SBP (p < 0.01). No variation was observed in DBP, heart rate and pupil diameter (p >0.01). Moreover, after drug administration, the total outflow facility measured by conventional tonography increased in a statistically significant way (p < 0.01). Placebo did not induce any significant reduction in IOP and SBP in either group.

CONCLUSION

The results showed that systemic ketanserin can be used in the treatment of glaucoma patients to reduce IOP.

End-stage renal disease, atherosclerosis, and cardiovascular mortality: is C-reactive protein the missing link?

In uremic patients, the morbidity and mortality of cardiovascular disease are substantially higher than in the general population. This has led to the formulation of an 'accelerated atherogenesis' hypothesis in uremic patients and has been commonly linked with the metabolic alterations associated with uremia. Advancement in the understanding of the pathogenesis of atherosclerotic vascular disease now suggests a central contribution of inflammation to atherogenesis, with involvement of a number of key mediators and markers of the inflammatory process. Recent epidemiological data have documented associations between C-reactive protein (CRP), the prototypical acute phase response protein, and cardiovascular disease in general population. Given the lipoprotein binding and complement activation functions of CRP and its localization in atherosclerotic vessels, there is a strong likelihood that CRP may be involved in the atherosclerotic process. The uremic state is associated with an altered immune response, which is associated with elevated proinflammatory cytokine levels. CRP concentrations are increased in a significant proportion of end-stage renal disease patients and have been associated with certain clinical outcome measures, including all-cause and cardiovascular mortality. This review outlines the evidence linking CRP with atherosclerosis and proposes that elevated CRP concentrations may be involved in the initiation and progression of accelerated atherosclerosis in uremia.

Bone mineral density in haemodialysis patients: A comparative study of dual-energy X-ray absorptiometry and quantitative ultrasound

BACKGROUND

Quantitative ultrasound (QUS) of bone is a relatively new technique that appears to assess 'bone quality' in addition to bone mineral density. The purpose of this study was to evaluate the diagnostic potential of QUS of calcaneum and to correlate it with dual energy X-ray absorptiometry (DEXA) in chronic haemodialysis patients.

METHODS

Broad-band ultrasound attenuation (BUA; dB/MHz) and speed of sound (SOS; m/s) of calcaneum and DEXA (g/cm(2)) measurements of the lumbar spine and hip were made in 39 patients. The indices obtained by either method were compared with age-and sex-matched controls. Calcaneal measurements were correlated to DEXA and relevant clinical and biochemical data of patients.

RESULTS

BUA and SOS values were markedly reduced in dialysis patients compared to controls (59.1+/-13.8 vs 73.0+/-16.2 dB/MHz, P:<0.001 and 1533+/-28 vs 1560+/-29 m/s, P:=0.014 respectively). There was a moderate, but significant association between calcaneal parameters and DEXA (r=0.32-0.53, P:<0.05). Both BUA and SOS scores were inversely correlated with age (r=-0.69, P:<0.001) and duration of menopause (r=-0.74, P:<0.01). Additionally, BUA values showed a moderate negative association with serum intact parathyroid values (r=-0.38, P:=0.018).

CONCLUSION

Chronic haemodialysis patients have reduced calcaneal BUA and SOS scores. QUS of the calcaneum is an easy-to-apply and radiation-free technique. It could be a useful substitute for assessment of bone density in such patients. However, further studies in large patient groups and comparisons with plasma markers of bone turnover and bone biopsy findings are needed to assess its potential place in the management of renal osteodystrophy.

Compliance in hemodialysis patients: unanticipated monitoring of biochemical indices

Compliance with the prescribed medical regimen is a critical factor for the continued well-being of hemodialysis patients. As compliance is a multifactorial problem, numerous approaches have been utilized to quantify the compliance of hemodialysis patients. In the present study, we have attempted to examine whether unanticipated control of biochemical indices might predict the compliance status of hemodialysis patients. We compared unanticipated mid-month values of blood urea nitrogen (BUN), serum potassium (K) and phosphate (PO4) values of 54 maintenance hemodialysis patients with the scheduled, regular first-week measurements during a 6-month study period. The interdialytic weight gain (IWG) levels of the corresponding weeks were also compared. Mid-month analysis revealed a significant deviation in the compliance status of the study population as BUN, serum K and IWGs were concerned (p < 0.05). The mid-month serum PO4 levels were also higher but the difference was not significant (p < 0.05). In conclusion, the differences observed in biochemical indices upon change of test request timing were distinctive. It suggests that unanticipated control of biochemical indices might contribute to the actual assessment of compliance in hemodialysis patients.

Diagnostic value of cervical discography in the management of cervical discogenic pain

We did a retrospective analysis of patients who had a total of 46 cervical discs examined by cervical discography and then evaluated the postoperative results of 14 of the 16 patients who underwent cervical spine fusion at those levels in accordance with the results of our discograms. The average symptomatic period prior to discography was 12 months, and cervical discogenic pain was successfully localized in all 16 patients. Immediately post-cervical discectomy and anterior fusion, subjectively, all 14 patients had good to excellent results, and after a mean follow-up of 6.5 (1.5 to 14) months, 11 patients (78.6%) continued with good to excellent results and three patients (21.4%) developed related pain patterns. Thus, cervical discography, in a "select group" of patients with chronic intractable neck pain but negative or indeterminate imaging findings who are being considered for surgical intervention, can help localize the symptomatic level and potentially benefit the patients by surgical intervention.

Protein Z levels in haemodialysis patients

Protein Z (PZ) is a vitamin K-dependent protein isolated from human and bovine plasmas. Although the exact role of PZ in the haemostatic system is presently unknown, it is suggested that PZ deficiency may cause bleeding tendency. Haemostatic alterations in end-stage renal failure (ESRF) are certainly complex and involve several abnormalities in the coagulation and fibrinolytic system. In order to elucidate the detail of the haemostasis in ESRF, we aimed to investigate PZ activity in haemodialysis patients. Therefore, we compared plasma PZ levels in 10 haemodialysis patients (6 M, 4 F, mean age 36+/-11) and 10 healthy normal controls (5 M, 5 F, mean age 34+/-8) in this study. We found mean plasma PZ levels in haemodialysis patients and healthy controls 6.95+/-2.93 microg/ml and 3.06+/-0.81 microg/ml, respectively (p<0.005). Increased level of PZ which influences the action of thrombin on its protein substrates and inhibitors may contribute to the haemostatis alterations in ESRF patients, in addition to other well known abnormalities in the coagulation and fibrinolytic system.

A unifying hypothesis for the renin-angiotensin system and hematopoiesis: sticking the pieces together with the JAK-STAT pathway

JAK-STAT pathway is a recently encountered intracellular signal transduction system. The pathway is utilized by numerous cytokines, growth factors, and hormones for gene expression and a variety of biological activities. Hematopoiesis is regulated by many cytokines and growth factors that support the proliferation and differentiation of progenitor cells in the bone marrow. JAK-STAT pathway arises as the most common signalling cascade of a wide range of cytokines and/or growth factors in propagation of physiological and pathological/neoplastic hematopoiesis. On the other side, renin-angiotensin system (RAS) includes not only the classic circulating endocrine system controlling blood pressure and electrolyte homeostasis, but also tissue-specific RASs with autocrine and/or paracrine functions. Preliminary data suggest the involvement of the RAS components in normal and pathologic hematopoiesis, although the precise mechanism of action has not been elucidated yet. We have hypothesized, in this report, that JAK-STAT pathway serves as a point of crosstalk between the components of the locally present RAS in the bone marrow and hematopoiesis. Demonstration of a local RAS in the bone marrow with clarification of the postreceptor signalling events may play a consequential role not only for further clarification of normal hematopoiesis but also novel therapeutic approaches in pathologic/neoplastic conditions.

Effects of angiotensin converting enzyme and angiotensin II receptor inhibition on impaired fibrinolysis in systemic hypertension

Abnormalities in fibrinolysis have been reported in hypertension. Angiotensin converting enzyme (ACE) inhibitors have been shown to improve altered fibrinolytic balance in hypertensive patients. It has not been documented, however, whether this is due to a decrease in angiotensin II (Ang-II) generation or is a consequence of elevated local levels of bradykinin. Accordingly, the aim of this study was to determine the effects of an ACE inhibitor (perindopril) and an Ang-II receptor antagonist (losartan) on fibrinolytic kinetics. We have examined the serum levels of the plasminogen activator inhibitor type-1 (PAI-1) antigen and activity, tissue plasminogen activator (t-PA) antigen and activity, soluble thrombomodulin (sTM), and tissue factor pathway inhibitor (TFPI) before and after reaching the target blood pressure (<140/90 mm Hg) in 13 hypertensive patients receiving perindopril (mean age 40+/-11 years, 6 women, 7 men) and in 12 patients receiving losartan (mean age 38+/-9 years, 6 women, 6 men). We also compared the baseline fibrinolytic activity of hypertensive patients with that of 12 normotensive control persons (mean age 40+/-9 years, 6 women, 6 men). The mean basal plasma levels of PAI-1 antigen, PAI-1 activity, and sTM were significantly higher in the hypertensive patients than in normal controls (P<.005). The values of other analytes were similar in both groups. Increased plasma levels of PAI-1 antigen, PAI-1 activity, and sTM were reduced in patients after they were given perindopril and losartan (P<.005); the reductions in losartan-receiving group were more pronounced (P<.05). There were no significant effects on the plasma levels of t-PA antigen, t-PA activity, and TFPI in patients receiving the two therapeutic regimens (P>.05). In conclusion, chronic hypertension is associated with hypofibrinolysis. The beneficial effect of ACE inhibitors on fibrinolysis seems to be related to the blockade of Ang-II, and increased kinin activity does not appear to play a major role.

Determinants of soluble CD23 antigen levels in hemodialysis patients: effect of 1.25 dihydroxyvitamin D3 and recombinant human erythropoietin treatment

BACKGROUND

The immunodeficiency of end-stage renal disease (ESRD) paradoxically coexists with T cell and monocyte activation. In spite of well known defective antibody responses in ESRD, the functional status of B cells in the immune system dysregulation of uremia is still controversial. Soluble CD23 (sCD23) antigen is a recently identified B cell activation marker and is also involved in T cell activation process. Effects of parathyroid hormone (PTH), red blood cells and ferritin on T and B cell functions have been shown both in vivo and in vitro.

PATIENTS AND METHODS

In this study, serum levels of sCD23 in hemodialysis patients were determined to evaluate the functional status of B cells and possible linkages between this cytokine and PTH levels, ferritin levels, red blood cell counts were investigated.

RESULTS

Serum sCD23 levels were significantly elevated in hemodialysis patients relative to healthy controls (12.5+/-8.4 micro/l vs. 2.4+/-1.1 micro/l, p<0.001). Serum sCD23 levels were negatively correlated with red blood cell count (r = -0.61, p = 0.009) and serum PTH levels (r = -0.62, p = 0.008), while positively correlated with serum ferritin levels (r = 0.63, p = 0.007) in hemodialysis patients. We also investigated the immunumodulator effects of 1.25 dihydroxyvitamin D3 (1.25OHD3) and recombinant human erythropoietin (rHu-Epo) treatment in hemodialysis patients. 1.25OHD3 treatment for eight weeks did not change serum sCD23 levels in hemodialysis patients (n = 8). On the other side, rHu-Epo administration for 16 weeks led to a decrease in serum sCD23 levels (17.7+/-8.6 microg/l vs. 9.8+/-3.5 microg/l, p = 0.007) in these patients (n = 9).

CONCLUSION

These results suggests that similar to T cells, B cells are activated in uremia and the degree of this activation is correlated with red blood cell count, serum parathyroid hormone levels and iron status of the hemodialysis patients. Moreover, B cell activation could be altered by recombinant human erythropoietin therapy in hemodialysis patients.

Serum thrombopoietin levels in haemodialysis patients: involvement of arteriovenous fistula

BACKGROUND

Thrombopoietin (Tpo) is a recently cloned growth factor which plays a critical role in the regulation of thrombopoiesis. Tpo has also been shown to stimulate in vitro and in vivo erythroid cell growth. Although Tpo transcripts were detected in hepatocytes, proximal tubules and endothelium, mechanisms regulating the level of circulating Tpo have not been fully delineated. Changes in the vessel wall and blood flow in arteriovenous fistula (AVF) might alter Tpo activity.

METHODS

Serum thrombopoietin levels and serum erythropoietin levels in samples concurrently obtained from venous returns of AVF and contralateral peripheral veins in 31 haemodialysis patients were determined and compared with 12 healthy controls. Levels were also compared between 14 haemodialysis patients (group I) treated with recombinant human erythropoietin (rHu-Epo) and 17 haemodialysis patients (group II) not requiring rHu-Epo.

RESULTS

Serum Tpo levels (44.8 +/- 23.9 pg/ml, vs 129.9 +/- 113.6 pg/ml, P<0.05) and platelet counts (194 +/- 55, 10(6)/ml vs 273 +/- 94. 10(6)/ml, P<0.05) of haemodialysis patients were lower than healthy controls. Serum Tpo levels were inversely correlated with platelet counts in the control group (R=-0.61, P<0.05), but not in haemodialysis patients. Tpo concentrations of AVF samples were lower than peripheral venous samples (31.6 +/- 17.7 pg/ml vs 44.8 +/- 23.9 pg/ml, P=0.001). No significant difference was present between the serum Tpo concentrations of haemodialysis patients in group I and group II. Serum Tpo levels were not correlated with haemoglobin levels or serum erythropoietin levels in haemodialysis patients.

CONCLUSION

Decreased serum Tpo levels despite low platelet counts in haemodialysis patients suggest that the proposed feedback mechanism of platelet uptake of Tpo is not fully operative in these patients. Moreover, AVF might affect the local production and/or catabolism of this growth factor.