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

The validity and reliability of the 6 minute stepper test in patients with systemic hypertension

Funding Acknowledgements

Type of funding sources: None.

Introduction and Background

6 Minute Stepper Test (6MST) is a valid, reliable and practical field test that evaluates exercise capacity in chronic conditions. There is a need for evaluating the validity and reliability of 6MST in for using evaluation during cardiac rehabilitation.

Purpose

The aim of this study was to evaluate the validity and reliability of 6MST test in patients with systemic hypertension.

Methods

Forty hypertensive individuals (mean age: 47.55 ± 6.55 years, female/male: 24/16) were included in the study. Demographic and clinical characteristics of patients were recorded and echocardiography was conducted. Functional exercise capacity was evaluated with 6MST and step number during 6MST was recorded. Exercise capacity was tested with the six minutes walk test (6MWT) and used for validity.

Results

Clinical and demographic status of patients were presented in Table-1. According to the test-retest ICC (Intraclass correlation coefficient) analysis for the reliability of 6MST test in hypertensive patients; 6MST test score has very good reliability for single measurements (ICC value = 0.896, p &lt;0.001) and mean measurements (ICC value = 0.945, p &lt;0.001). According to the results of pearson correlation analysis to evaluate the criterion validity of 6MST test; 6MST test score showed a high relationship with 6MWT distance as the criterion test (r = 0.689, p&lt;0.001) in patients with systemic hypertension.

Conclusions

6MST can be used as a valid and reliable test to evaluate exercise capacity in patients with hypertension. Because it is practical, tolerable and safe so it may be a new valid field test in cardiac rehabilitation.

Assessment of plasma microRNA potentials as a non-invasive biomarker in patients with axial spondyloarthropathy

OBJECTIVE

It is assumed that abnormally expressed MicroRNAs (miRNAs) may be present in the plasma of patients with radiographic axial spondyloarthropathy (rad-AxSpA). Thus, the present study was conducted with the aim of investigating the expression profile of miRNAs in patients with rad-AxSpA.

PATIENTS AND METHODS

A total of 15 patients diagnosed with rad-AxSpA according to the Assessment of the SpondyloArthritis International Society (ASAS) classification criteria and nine healthy controls matched for age and gender were included in the study. Demographic data were collected, and disease activity was evaluated using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Peripheral blood samples were collected, and miRNAs were extracted. The expression of microRNAs was analyzed using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) by the miScript miRNA PCR Array Human Inflammatory Response and Autoimmunity.

RESULTS

A total of 84 miRNA profiles were evaluated, and expressions in the study and control groups were compared. When compared to the control group, 6 miRNAs (miR-125b-5p, miR-144-3p, miR-19a-3p, miR-20a-5p, miR-29c-3p, miR-30b-5p) were detected to be upregulated, and 42 miRNAs were detected to be downregulated in the rad-AxSpA group. A p-value < 0.05 was accepted as statistically significant. A significant association was found between miR-145-5p and BASDAI (p = 0.04941). MiR-144-3p, miR-302b-3p, miR-381-3p, miR-497-5p, miR-511-5p, and miR-9-5p were found to be significantly upregulated in the HLA-B27+ patients (p = 0.03063).

CONCLUSIONS

Abnormal miRNA expressions were detected in the plasma of the patients with rad-AxSpA. It was concluded that comprehensive studies should be continued to define these miRNAs as diagnostic biomarkers for rad-AxSpA in order to detect its association with Ankylosing Spondylitis disease activity.

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

The association between the lymphocyte-to-monocyte ratio and coronary artery disease severity in patients with stable coronary artery disease

OBJECTIVE

Inflammation plays an important role in the pathogenesis of atherosclerosis. The lymphocyte-to-monocyte ratio (LMR) may reflect a systemic inflammatory status. We investigated the association between the LMR and coronary artery disease (CAD) in patients with stable angina pectoris.

PATIENTS AND METHODS

A total of 221 consecutive patients who had been routinely referred for coronary angiography, for stable angina pectoris and 72 patients with normal coronary arteries were included in the present study. We analyzed the relation between the LMR and the angiographic severity of CAD. The SYNTAX score (SxS) was used for assessing the severity of coronary atherosclerosis.

RESULTS

The neutrophil-to-lymphocyte ratio (N/L ratio), platelet size distribution width (PDW), neutrophil and uric acid levels were significantly higher in the stable angina pectoris group than in the control group. The LMR was significantly lower in the stable angina pectoris group than in the control group (4.5±3.2 vs. 6±2.9, p < 0.001). The MPV/L ratios were similar in both groups. Patients with elevated SYNTAX scores (>32) had lower LMR values (3.2±1.5 vs. 4.6±3, p = 0.002). The monocyte count/HDL-C ratio (MHR) was significantly higher in patients with stable CAD than in the control group (0.015±0.008 vs 0.009±0.004, p < 0.001); however, it was similar in the higher SYNTAX score (>32) and lower SYNTAX score groups (0.018±0.007 vs. 0.014±0.008, p = 0.056). Using multivariate logistic regression analysis, we found that only the LMR was an independent predictor of the high SYNTAX scores in patients with stable angina pectoris.

CONCLUSIONS

 The LMR, an inexpensive and easily measurable laboratory variable, is significantly associated with the presence of CAD and high SYNTAX scores in patients with stable angina pectoris.

PROTECTIVE EFFECT OF NIGELLA SATIVA OIL ON MYOCARDIUM IN STREPTOZOTOCIN-INDUCED DIABETIC RATS

Background

To evaluate the protective effect of Nigella sativa oil (NSO) on the myocardium in streptozotocin-induced diabetic rats.

Materials and methods

Thirty-two 7-8-week-old female Wistar albino rats (300-350 g) were equally divided into 4 groups: nondiabetic untreated animals (control), diabetes mellitus (DM), NSO, and DM+NSO groups. For the induction of diabetes, 45 mg/kg streptozotocin was applied to the rats in the DM and DM+NSO groups as a single intraperitoneal dose. NSO (400 mg/kg) was orally administered through an intragastric catheter once a day over 21 days. Formalin-fixed, paraffin-embedded tissue sections of the myocardium were evaluated histopathologically and immunohistochemically.

Results

Compared to the control, NSO, and DM+NSO groups, the myocardial tissue samples from the rats in the DM group had significantly higher myositis, hyaline degeneration, and Zenker's necrosis. Moreover, the Bcl-2 expressions were significantly higher in the control, NSO, and DM+NSO groups than in the DM group.

Conclusion

NSO has a protective effect on the myocardium of streptozotocin-induced diabetic rats, most likely via suppressing apoptosis.

Combining clinical predictors to better predict for the no-reflow phenomenon

OBJECTIVE

We aimed to determine whether the combination of a CHA2DS2-VASc score (C: Congestive Heart Failure, H: Hypertension, A2: Age ≥ 75 years, D: Diabetes mellitus, S: Stroke history, V: Vascular disease, A: Age ≥ 65 years, Sc: Sex category) and pre-percutaneous coronary intervention (PCI) thrombus load score was more sensitive at detecting the no-reflow phenomenon compared to the CHA2DS2-VASc score alone or to the thrombus load score alone in patients with acute ST-elevation myocardial infarction (STEMI) who had underwent primary PCI (PPCI).

PATIENTS AND METHODS

497 patients with acute STEMIs were divided into two groups: no-reflow group (n: 194) and control group (n: 303). The Thrombolysis In Myocardial Infarction (TIMI) flow grading and Myocardial Blush Grade (MBG) were used together to define angiographic no-reflow as TIMI flow < 3 (with any MBG grade) or TIMI flow 3 with MBG 0 or 1. Successful reperfusion was defined as TIMI flow 3 with MBG 2 or 3.

RESULTS

CHA2DS2-VASc score was significantly higher in the no-reflow group than in the control group (2 [1-4] vs. 1 [0-3], p < 0.001]. Compared with the control group, the no-reflow group had a higher pre-PCI thrombus score (5 [4-5] vs. 4 [3-5], p = 0.001). Compared with the CHA2DS2-VASc score alone, the combined use of the pre-PCI thrombus score and the CHA2DS2-VASc score was associated with significant improvements in the ability to predict no-reflow (AUC) (0.65 vs. 0.60, p < 0.05). The addition of the pre-PCI thrombus score to the CHA2DS2-VASc score was related to a significant net reclassification improvement of 6.7% (p = 0.047) and an integrated discrimination improvement of 0.036 (p < 0.05).

CONCLUSIONS

We have found that the combination of a CHA2DS2-VASc score and a pre-PCI thrombus load score was more sensitive in detecting the no-reflow phenomenon than only a CHA2DS2-VASc score in patients who underwent PPCIs for STEMIs.

Neuroprotective effects of high-dose human albumin against traumatic spinal cord injury in rats

BACKGROUND AND OBJECTIVES

Human serum albumin (HA) is a unique multifunctional protein with neuroprotective properties. We aimed to delineate the mechanisms of HA-induced neuroprotection, supresses inflammatory response and lipid peroxidation after spinal cord injury (SCI).

METHODS AND STUDY DESIGN

Adult female Wistar rats weighing 210-250 g were used for the study. The rats were randomly and blindly allocated into five groups. The one-way analysis of variance (ANOVA) for parametric data and Shapiro-Wilk test was used for evaluating the normal distribution of the variables. Kruskal-Wallis for nonparametric data was used to compare groups. Electron and light microscopies were used to demonstrate ultrastructural changes in spinal cord.

RESULTS

The HA group was significantly different from all the other groups (p < 0.05). Both MPSS and HA treatments decreased the MPO significantly. HA treatment decreased the lipid peroxidation. HA treatment prevented the worsening of clinical results. In the HA treatment group, the ultrastructure was protected significantly. The neuronal bodies and axonal structures were normal except for some limited edematous spaces.

CONCLUSIONS

HA improves early clinical results, protects spinal cord ultrastructure, and decreases MPO and LPO levels after spinal cord contusion injury (Tab. 3, Fig. 3, Ref. 39).

The role of pegaptanib sodium in the suppression of epidural fibrosis in a postlaminectomy rat model

OBJECTIVE

Spinal epidural fibrosis is a clinical condition that develops after laminectomy and can compress the spine. Many agents have been tried for the treatment, but none has entered clinical use at present. Pegaptanib sodium is an antiangiogenetic drug that prevents the development of new vessels and thus adhesion by inhibiting the effect of VEGF.

MATERIAL AND METHOD

20 Wistar rats were used in this study. The rats were divided into 2 different groups as the control and pegaptanib sodium group. Three levels of laminectomy were performed. Only laminectomy was performed in the control group. A cotton ball soaked with 3 mg/kg Pegaptanib sodium diluted 1: 10 with 0.9 % NaCl was topically applied to the dura in the surgical field for 5 minutes in the pegaptanib sodium group. The rats were sacrificed 3 weeks later and histopathologically examined. The epidural fibrosis was graded.

RESULTS

The epidural fibrosis grade in the pegaptanib sodium was significantly lower than in the control group c2 = 11,65; (p = 0.004)CONCLUSION: Pegaptanib sodium blocked the VEGF through its anti-VEGF effect and decreased spinal epidural fibrosis in rats that had undergone laminectomy (Tab. 2, Fig. 3, Ref. 53).

Radiopacity of bulk fill flowable resin composite materials

OBJECTIVES

The purpose of this study was to evaluate the radiopacity of currently marketed bulk fill flowable dental composite materials (Beautifil Bulk Flowable, SDR Flow, Filtek Bulk Fill Flow, and x-tra Base Bulk Fill).

MATERIALS AND METHODS

Six specimens of each material with a thickness of 1 mm were prepared, and digital radiographs were taken, using a CCD sensor along with an aluminum stepwedge and 1 mm-thick tooth slice. The mean gray level of each aluminum stepwedge and selected materials was measured, using the equal-density area tool of Kodak Dental Imaging software. The equivalent thickness of aluminum for each material was then calculated by using the stepwedge values in the CurveExpert version 1.4 program.

RESULTS

The radiopacity of bulk fill flowable composites sorted in descending order as follows: Beautifil Bulk Flowable (2.96 mm Al) = x-tra base bulk fill (2.92 mm Al) = SureFil SDR Flow (2.89 mm Al) > Filtek Bulk Fill Flow (2.51 mm Al) (P < 0.05).

CONCLUSIONS

As all materials had a radiopacity greater than dentin and enamel; their adequate radiopacity will help the clinicians during radiographic examination of restorations.

CLINICAL SIGNIFICANCE

Bulk fill composite materials have greater radiopacity, enabling clinicians to distinguish the bulk fill composites from dentin and enamel.

Effects of Er,Cr:YSGG Laser Pulse Frequency on Microtensile Bond Strength to Enamel

Literature regarding the influence of Er,Cr:YSGG laser pulse frequency with different output power levels on adhesion properties of adhesive resin to lased enamel is limited. Therefore, the aim of the present study was to evaluate the effects of laser pulse frequency (20, 35, and 50 Hz) at two different output power settings (3 and 6 W) of Er,Cr:YSGG on the microtensile bond strength (μTBS) of adhesive resin to enamel. Crowns of 35 intact bovine incisors were embedded into self-cure acrylic resin individually, and then flat enamel surfaces were prepared with 600-grit silicon carbide papers under water cooling. Teeth were divided randomly into seven groups. Enamel surfaces were irradiated with Er,Cr:YSGG laser operated at one of six output power–pulse frequency combinations (6 W20 Hz, 6 W–35 Hz, 6 W–50 Hz, 3 W–20 Hz, 3 W–35 Hz, and 3 W–50 Hz) in groups 1-6, respectively. Bur-treated surfaces served as a control in group 7. After surface treatments and bonding procedures, composite build-ups were done in three layers up to a height of 4 mm. Next, all bonded teeth were sectioned into the resin-enamel sticks to be tested in a μTBS testing machine. The μTBS data were analyzed with univariate analysis of variance under a general linear model with the factor ‘tooth' added as a random effect to the design. Resin-enamel interfaces were evaluated with scanning electron microscopy (SEM). The μTBS to laser-irradiated enamel in group 1 (6 W–20 Hz) was significantly lower than those of bur-treated enamel (p&lt;0.05). However, group 6 (3 W–50 Hz) showed significantly higher μTBS values than did bur-treated teeth (p&lt;0.05). SEM evaluation revealed enormous morphological alterations of laser-irradiated specimens, such as extensive vertical and horizontal microcracks and gaps, with the exception of group 6. The bonding effectiveness of adhesive resin to laser-irradiated enamel was affected by the pulse frequency of the Er,Cr:YSGG laser. Although the parameters recommended by the manufacturer lowered μTBS, increasing the pulse rate may maintain optimum μTBS.

The role of oxidative stress in the relation between fibromyalgia and obstructive sleep apnea syndrome

OBJECTIVE

The aim of this study is to examine the involvement of oxidative and antioxidative parameters and to evaluate the relation between fibromyalgia (FMS) and obstructive sleep apnea syndrome (OSAS).

PATIENTS AND METHODS

Oxidative stress was determined by measuring the levels of malondialdehyde (MDA) and antioxidative parameters (superoxide dismutase [SOD], catalase [CAT], and glutathione peroxidase [GPx]) in 131 randomly selected patients with OSAS. The control group was composed of 129 subjects with no clinical OSAS symptoms. OSAS was diagnosed by polysomnographic tests. All patients underwent overnight polysomnographic recording. The diagnosis of fibromyalgia was made following the diagnostic criteria of the American College of Rheumatology. The FMS patients used visual analog scales (VAS) to evaluate their pain, and they completed the FMS Impact Questionnaire (FIQ). All subjects completed the 36-item Short Form Health Survey (SF-36) and the Beck Depression Inventory (BDI).

RESULTS

In the OSAS + FMS group, CAT, SOD, and GDX were found to be statistically significantly lower and MDA was found to be statistically significantly higher than in both the control group and the OSAS group (p = 0.0001). A significant difference was found about gender between the OSAS group and the OSAS+FMS group (p = 0.0001). In the OSAS + FMS group, BDI was found to be statistically significantly higher than in both the control group and the OSAS group (p = 0.0001). In the OSAS + FMS group, SF 36 was found to be statistically significantly higher than in both the control group and the OSAS group (p = 0.0001). No differences were observed between the groups about AHI, minimum O2 saturation, or total sleep time values. About the presence of FMS presence, no differences were detected among the mild, moderate, and severe OSAS groups (p = 0.831). A negative correlation was determined between AHI and VAS and total sleep and sensitive points (p = 0.0001). A negative correlation was shown between CAT and GPX, SOD and apnea/hypopnea index (AHI) (p = 0.0001). A positive correlation was shown between CAT, GPX and SOD (p = 0.0001). A minimum O2 saturation was detected. A positive correlation between MDA and AHI (p = 0.0001), and a negative correlation between MDA and O2 saturation (p = 0.0001) were found.

CONCLUSIONS

OSAS and FMS were highly prevalent, which indicated that oxidative stress might play a role in the pathophysiology of both diseases, especially if they co-exist in the same patient.

Results of one-stage surgical treatment in children with Tönnis grade 4 developmental dysplasia of the hip: is it worse when it is bilateral?

This retrospective study compared the results of one-stage surgery of unilateral and bilateral Tönnis grade 4 hips (high dislocation in developmental hip dysplasia, DDH) : 41 hips, 30 patients. Mean follow-up was 56 months. Pelvic radiographs were evaluated at three time points. Acetabular inclination angle improved significantly in both groups. Results were satisfactory (Severin classes I-II) in 13 hips (68.5%) (unilateral group) and 21 hips (89.5%) (bilateral group). Functional evaluation (McKay classification) at final follow-up revealed satisfactory results in 94.8% (unilateral group) and 63.6% (bilateral group). One-stage surgery is a reliable method for treating children with unilateral or bilateral DDH.

Evaluation of microtensile and tensile bond strength tests determining effects of erbium, chromium: yttrium-scandium-gallium-garnet laser pulse frequency on resin-enamel bonding

OBJECTIVES

The aim of the present study was to compare two different bond strength test methods (tensile and microtensile) in investing the influence of erbium, chromium: yttrium-scandium-gallium-garnet (Er, Cr: YSGG) laser pulse frequency on resin-enamel bonding.

MATERIALS AND METHODS

One-hundred and twenty-five bovine incisors were used in the present study. Two test methods were used: Tensile bond strength (TBS; n = 20) and micro-TBS (μTBS; n = 5). Those two groups were further split into three subgroups according to Er, Cr: YSGG laser frequency (20, 35, and 50 Hz). Following adhesive procedures, microhybrid composite was placed in a custom-made bonding jig for TBS testing and incrementally for μTBS testing. TBS and μTBS tests were carried out using a universal testing machine and a microtensile tester, respectively.

RESULTS

Analysis of TBS results showed that means were not significantly different. For μTBS, the Laser-50 Hz group showed the highest bond strength (P < 0.05), and increasing frequency significantly increased bond strength (P < 0.05). Comparing the two tests, the μTBS results showed higher means and lower standard deviations.

CONCLUSION

It was demonstrated that increasing μTBS pulse frequency significantly improved immediate bond strength while TBS showed no significant effect. It can, therefore, be concluded that test method may play a significant role in determining optimum laser parameters for resin bonding.

Association of apelin, endoglin and endocan with diabetic peripheral neuropathy in type 2 diabetic patients

OBJECTIVE

Diabetic peripheral neuropathy is a common complication of type-2 diabetes mellitus. Endocan, apelin and endoglin are thought to be associated with endothelial dysfunction, angiogenesis and inflammation. In this study, we planned to evaluate these markers in diabetic peripheral neuropathy patients.

PATIENTS AND METHODS

This single-blind, controlled clinical study was conducted on 99 type 2 diabetic patients with or without diabetic peripheral neuropathy and 53 healthy volunteer controls. Physical and laboratory examinations were done in all groups. In these groups, Endoglin, apelin and endocan levels were measured with ELISA method.

RESULTS

Endoglin, apelin and endocan concentrations in diabetic peripheral neuropathy patients were higher than other diabetes mellitus patients and healthy controls. Similarly, diabetes mellitus patient's endoglin, apelin and endocan levels were higher than healthy controls. The differences were statistically significant. We detected a significant positive correlation between endoglin, apelin and endocan levels in all groups.

CONCLUSIONS

Endoglin, apelin and endocan may reflect angiogenesis and endothelial dysfunction in diabetic peripheral neuropathy and they may be used as a marker in the future.

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.

Medial malleolar screw hemiepiphysiodesis for ankle valgus in children with spina bifida

Medial malleolar screw hemiepiphysiodesis has been shown to be an effective procedure for the treatment of ankle valgus in children with spina bifida. The purpose of this study was to highlight the guided growth technique and discuss its efficacy. We retrospectively reviewed 10 spina bifida patients with 18 ankle valgus deformities treated with medial malleolar screw hemiepiphysiodesis. Medical reports were obtained to document age at surgery, gender, concurrent operative procedures and postoperative early and late complications. Anteroposterior and lateral weight bearing radiographs of both ankles were evaluated using the tibiotalar angle, pre and postoperatively. The average age at operation was 10.05 years. Average follow up was 15.33 months (11-21 months). During follow-up, the average preoperative distal tibiotalar angle of 16.27 degrees improved to an average of 2.88 degrees with statistical significance (p < 0.05). No major complications were detected. In conclusion, hemiepiphysiodesis is a safe and sufficient method to correct ankle valgus deformity in children with spina bifida, with a low incidence.

Association between urinary angiotensinogen, hypertension and proteinuria in pregnant women with preeclampsia

INTRODUCTION

Preeclampsia is a life-threatening disorder of pregnancy. The pathogenic mechanisms of preeclampsia remain uncertain. The aim of this study is to investigate the relation between urinary angiotensinogen (UAGT) levels, an indicator of local renin-angiotensin system (RAS) activity in the kidney, and blood pressure and urinary protein excretion in preeclampsia.

MATERIALS AND METHODS

For this study, 90 women aged between 20-39 years were recruited. Spot urine samples were collected to measure urinary angiotensinogen/creatinine ratio (UAGT/UCre). Log(UAGT/UCre) was compared in pregnancies with and without preeclampsia and non-pregnant controls. Factors affecting log(UAGT/UCre) in pregnancies were also investigated.

RESULTS

In all pregnancies log(UAGT/UCre) levels were significantly higher than in non-pregnant controls (0.58±0.19 vs. 0.33±0.14, respectively, p=0.002). However, log(UAGT/UCre) levels in pregnancies with preeclampsia were slightly lower than in normal pregnancies (0.52±0.18 vs. 0.64±0.19, respectively, p=0.012). Log(UAGT/UCre) levels were correlated positively with blood pressure and proteinuria in pregnancies with preeclampsia. However, log(UAGT/UCre) levels were not correlated with age, height, body weight, gestational age, body mass index, and serum creatinine.

CONCLUSION

This study showed that elevated local RAS activity in kidney was correlated with high blood pressure and proteinuria in preeclampsia. Local RAS activation in the kidneys may be one of the contributing factors in the development of preeclampsia.

Congenital infiltrating lipomatosis of the face with hemimegalencephaly

Congenital infiltrating lipomatosis of the face (CILF) is a rare disorder, causing unilateral facial asymmetry characterized by enlargement of the cheek or chin. Hemimegalencephaly is a unique malformation characterized by enlargement of a cerebral hemisphere. The association of CILF and hemimegalencephaly has rarely been reported. We present a case of unilateral facial swelling in a 1.5-year-old boy in whom magnetic resonance imaging and computed tomography revealed CILF associated with unilateral megalencephaly.

Atypical MRI Findings of Synchronous Cerebral Metastasis

Intracranial metastases represent 7% to 17% of all brain tumors. Metastases may appear before, after or synchronously with the primary tumor. Synchronous tumor presentation means that that metastasis is found within two months of primary tumor diagnosis. A 60-year-old man was seen 15 days after the acute onset of confusion and gait disturbance. Results of a neurologic examination revealed disorientation, dysarthria, and left-sided ataxia. Results of nonenhanced computed tomography scanning of the brain were unremarkable. Cerebral magnetic resonance imaging showed multiple miliary, round, small (maximum diameter, 1 cm) lesions located infra- and supratentorially. Gradient-echo magnetic resonance images of these lesions were compatible with hemorrhage and were more pronounced compared with other sequences. Hemorrhagic cerebral metastases were suspected, and the patient was examined for primary tumors. Chest computerized tomography revealed a tumor in the posterior, superior lobe of the right lung; a cervical lymph node biopsy suggested a metastatic carcinoma. Our case illustrates that magnetic resonance imaging findings of synchronous cerebral multiple metastases presenting with neurologic symptoms may be atypical while the results of cerebral computerized tomography are normal. Contrast-enhanced cerebral magnetic resonance imaging, especially gradient-echo magnetic resonance sequences, should always be considered for diagnosing hemorrhagic metastases in patients presenting neurologic findings with a known or unknown cancer.

Strong coupling of the Fe-spin state and the As-As hybridization in iron-pnictide superconductors from first-principle calculations

From first-principles calculations, we unravel surprisingly strong interactions between arsenic ions in iron pnictides, the strength of which is controlled by the Fe-spin state. Reducing the Fe-magnetic moment weakens the Fe-As bonding, and in turn, increases As-As interactions, causing giant reduction in the c axis. For the CaFe2As2 system, this reduction is as large as 1.4 angstroms. Since the large c reduction has been recently observed only under high pressure, our results suggest that the iron magnetic moment should be present in Fe-pnictides at all times at ambient pressure. Finally, the conventional electron-phonon coupling in the collapsed phase of CaFe2As2 gives a maximum Tc of 0.6 K and cannot explain the approximately 12 K superconductivity observed in some experiments. Implications of these findings on the mechanism of superconductivity in iron pnictides are discussed.

Crystal structure and antiferromagnetic order in NdFeAsO1-xFx (x=0.0 and 0.2) superconducting compounds from neutron diffraction measurements

The transition temperature T{C} approximately 26 K of the recently discovered superconductor LaFeAsO1-xFx is extremely sensitive to the lanthanide ion, reaching 55 K for the Sm containing oxypnictides. Therefore, it is important to determine how the moment on the lanthanide affects the overall magnetism in these systems. Here we report a neutron diffraction study of the Nd oxypnictides. Long-ranged antiferromagnetic order is apparent in NdFeAsO below 1.96 K. Rietveld refinement shows that both Fe and Nd magnetic ordering are required to describe the observed data with the staggered moment 1.55(4)micro{B}/Nd and 0.9(1)micro{B}/Fe at 0.3 K. The other structural properties such as the tetragonal-orthorhombic distortion are found to be very similar to those in LaFeAsO. Neither the magnetic ordering nor the structural distortion occur in the superconducting sample NdFeAsO0.80F0.20 at any temperatures down to 1.5 K.

External magnetic field effects on a distorted kagome antiferromagnet

We report bulk magnetization, and elastic and inelastic neutron scattering measurements under an external magnetic field H on the weakly coupled distorted kagome system, Cu2(OD)3Cl. Our results show that the ordered state below 6.7 K is a canted antiferromagnet and consists of large antiferromagnetic ac components and smaller ferromagnetic b components. By first-principles calculations and linear spin wave analysis, we present a simple spin Hamiltonian with nonuniform nearest neighbor exchange interactions resulting in a system of coupled spin trimers with a single-ion anisotropy that can qualitatively reproduce the spin dynamics of Cu2(OD)3Cl.

Origin of the 150-K anomaly in LaFeAsO: competing antiferromagnetic interactions, frustration, and a structural phase transition

From all-electron fixed-spin-moment calculations we show that ferromagnetic and checkerboard antiferromagnetic ordering in LaFeAsO are not stable and the stripe antiferromagnetic configuration with M(Fe)=0.48 microB is the only stable ground state. The main exchange interactions between Fe ions are large, antiferromagnetic, and frustrated. The magnetic stripe phase breaks the tetragonal symmetry, removes the frustration, and causes a structural distortion. These results successfully explain the magnetic and structural phase transitions in LaFeAsO recently observed by neutron scattering. The presence of competing strong antiferromagnetic exchange interactions suggests that magnetism and superconductivity in doped LaFeAsO may be strongly coupled, much like in the high-T(c) cuprates.