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Biomedical subjects

Aysin Bakkaloglu

Publications and source records attributed to Aysin Bakkaloglu.

At least 19 recordsLinked to original sources

Takayasu arteritis in children: preliminary experience with cyclophosphamide induction and corticosteroids followed by methotrexate.

OBJECTIVE: To review the results of our treatment protocol in the last 7 years. STUDY DESIGN: Six patients (4 girls, 2 boys) with an age range of 12 to 17 years were diagnosed with Takayasu arteritis (TA) during this period. Patients were allocated to receive (1) oral steroids and methotrexate (MTX) (12.5 mg/m(2)/week) if they had disease limited to one side of the diaphragm only without pulmonary disease involvement (two patients); and (2) oral steroids and oral cyclophosphamide (CYC) (maximum total dose 150 mg/kg) followed by oral MTX for maintenance as above if the disease was more widespread (four patients). RESULTS: One patient died of pulmonary vasculitis during the first month of therapy. The remaining three patients with involvement of both the thoracic and abdominal aorta and branches received the second protocol for 12 to 18 months. All entered remission. Aortic bypass, aortorenal bypass, balloon dilatation, and unilateral nephrectomy were performed in these patients. CONCLUSIONS: The presented single-center experience suggests that CYC induction and corticosteroids followed by MTX is an effective and safe treatment for childhood TA.

Administration, Oral↗

Is the CD14 C159T polymorphism effective in the development of secondary amyloidosis in Familial Mediterranean fever?

The most important complication of FMF is the development of amyloidosis. It is more common in the eastern Mediterranean compared to the US. The individual response to endotoxin may have a significant effect on the development of amyloidosis in FMF patients. To investigate the association between CD14 promotor C-159T polymorphism and development of amyloidosis, one hundred and forty-six patients who had FMF and had not developed amyloidosis; 26 with FMF and secondary amyloidosis and 92 controls were genotyped at the CD14-C159T locus. There was no difference between the genotype distribution of FMF patients (CC 30.0%, CT 50.0%, TT 20.0%) and controls (CC 29.2%, CT 45.8%, TT 25%); or between FMF patients with amyloidosis (CC 30.8%, CT 53.8%, TT 15.4%) or without amyloidosis (CC 29.2%, CT 45.8%, TT 25%). Our study shows that the CD14-C159T polymorphism is not associated with FMF or development of amyloidosis in the population studied. The effect of the genetic variations in the endotoxin signaling pathway under different environmental conditions such as high and low endotoxin exposure remain to be determined.

Adolescent↗

Positional cloning uncovers mutations in PLCE1 responsible for a nephrotic syndrome variant that may be reversible.

Nephrotic syndrome, a malfunction of the kidney glomerular filter, leads to proteinuria, edema and, in steroid-resistant nephrotic syndrome, end-stage kidney disease. Using positional cloning, we identified mutations in the phospholipase C epsilon gene (PLCE1) as causing early-onset nephrotic syndrome with end-stage kidney disease. Kidney histology of affected individuals showed diffuse mesangial sclerosis (DMS). Using immunofluorescence, we found PLCepsilon1 expression in developing and mature glomerular podocytes and showed that DMS represents an arrest of normal glomerular development. We identified IQ motif-containing GTPase-activating protein 1 as a new interaction partner of PLCepsilon1. Two siblings with a missense mutation in an exon encoding the PLCepsilon1 catalytic domain showed histology characteristic of focal segmental glomerulosclerosis. Notably, two other affected individuals responded to therapy, making this the first report of a molecular cause of nephrotic syndrome that may resolve after therapy. These findings, together with the zebrafish model of human nephrotic syndrome generated by plce1 knockdown, open new inroads into pathophysiology and treatment mechanisms of nephrotic syndrome.

Animals↗

Arg753Gln TLR-2 polymorphism in familial mediterranean fever: linking the environment to the phenotype in a monogenic inflammatory disease.

OBJECTIVE: Familial Mediterranean fever (FMF) is an autoinflammatory disease common in eastern Mediterranean populations. The most severe complication is the development of secondary amyloidosis. Toll-like receptor (TLR-2) plays a critical role in linking the recognition of microbes to immune activation. We investigated whether the Arg753Gln TLR2 polymorphism affected the development of secondary amyloidosis in patients with FMF. METHODS: We studied 75 patients with FMF, 40 patients with FMF who developed secondary amyloidosis, and 116 healthy controls. TLR2 gene Arg753Gln mutations were analyzed with a polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The frequency of the Arg753Gln TLR2 polymorphism among the Turkish population was 6%, whereas it was 25.2% among patients with FMF (p < 0.01). The difference of the frequency of the polymorphism between FMF patients with and without amyloidosis was significant: 15/40 (37.5%) and 14/75 (18.6%), respectively (p = 0.02). CONCLUSION: The Arg753Gln polymorphism may affect the severity of this monogenic disease by influencing the innate immune response to pathogens. The presence of the polymorphism may influence the phenotype of FMF in geographic areas where bacterial insult is more common.

Amyloidosis↗

Childhood vasculitides in Turkey: a nationwide survey.

AIM: The aims of this study were to evaluate the characteristics of childhood vasculitides and to establish the first registry in Turkey, an eastern Mediterranean country with a white population. PATIENTS AND METHODS: A questionnaire was distributed to the main referral centers asking for the registration of the Henoch-Schönlein purpura (HSP) patients in the last calendar year only and 5 years for other vasculitides. Demographic, clinical, and laboratory data were assessed. RESULTS: Vasculitic diseases were registered from 15 pediatric centers. These centers had a fair representation throughout the country. In the last calendar year, incidences were as follows: HSP 81.6%, Kawasaki disease (KD) 9.0%, childhood polyarteritis nodosa (C-PAN) 5.6%, Takayasu arteritis (TA) 1.5%, Wegener's granulomatosis 0.4%, and Behçet disease 1.9%. There was no clear gender dominance. The mean age was 11.05+/-4.89 years. Acute phase reactants were elevated in almost all, highest figures being in C-PAN. Renal involvement was present in 28.6% of HSP and 53% of the C-PAN patients. Abdominal aorta was involved in all TA patients. Among the C-PAN patients, 25% had microscopic PAN with necrotizing glomerulonephritis; antineutrophil cytoplasmic antibody was positive in those who were studied. Among the patients, 12.5% and 15% had classic PAN and cutaneous PAN, respectively. The remaining majority were classified as systemic C-PAN diagnosed with biopsies and/or angiograms demonstrating small to midsize artery involvement. The overall prognosis was better than reported in adult series. CONCLUSION: This is the largest multicenter study defining the demographic data for childhood vasculitides. The distribution of childhood vasculitides was different in our population where KD is much less frequent, whereas HSP constitutes an overwhelming majority. C-PAN was more frequent as well.

Adolescent↗

Cytomegalovirus-related congenital nephrotic syndrome with diffuse mesangial sclerosis.

This case report describes congenital nephrotic syndrome in a 2-month-old girl associated with cytomegalovirus infection. Histological examination on renal biopsy showed diffuse mesangial sclerosis and cytomegalic inclusion bodies in the tubular cells and in some glomeruli. Cytomegalovirus (CMV) polymerase chain reaction (PCR) titer in serum was high. Remission of pulmonary and renal symptoms was achieved with ganciclovir in 3 weeks. No recurrence of proteinuria was observed during the follow-up period of 14 months. These finding suggested a causal relationship between congenital nephrotic syndrome and cytomegalovirus infection.

Adult↗

Mutations in Uroplakin IIIA are a rare cause of renal hypodysplasia in humans.

BACKGROUND: Renal hypodysplasia, characterized by a decrease in nephron number, small overall kidney size, and maldeveloped renal tissue, is a leading cause of chronic renal failure in young children. Familial clustering and renal hypodysplasia phenotypes observed in transgenic animal models suggest a genetic contribution. Uroplakin IIIa (encoded by UPIIIA) is an integral membrane protein present in urothelial plaques, and the murine UPIIIa knockout is associated with urothelial anomalies and vesicoureteral reflux. De novo UPIIIA mutations recently were identified in 4 of 17 patients with severe bilateral renal adysplasia. METHODS: To evaluate the overall role of UPIIIA in human renal hypodysplasia pathogenesis, we performed UPIIIA mutation analysis in a cohort of 170 pediatric patients affected by severe unilateral or bilateral renal hypodysplasia. Eighty-one patients were affected by bilateral nonobstructive renal hypodysplasia; of these, 61 were without vesicoureteral reflux. Eighty-four patients presented with unilateral nonobstructive renal hypodysplasia, including 24 patients with unilateral multicystic dysplastic kidneys. Family history was positive in 11%. RESULTS: Mutation analysis showed 2 heterozygous mutations not observed in 200 race-matched control chromosomes. In only 1 family was distribution of the UPIIIA mutation consistent with a disease-causing effect. This de novo missense mutation (Gly202Asp) was identified in a patient with unilateral multicystic dysplastic kidneys. The second (intronically located) mutation appeared unlikely to be disease causing because it did not segregate with an obvious disease phenotype in the affected family. CONCLUSION: Our results indicate that de novo mutations in UPIIIA can be involved in defective early kidney development, but probably constitute only a rare cause of human renal hypodysplasia in a minor subset of individuals.

Adolescent↗

Cyclosporine drug monitoring with C0 and C2 concentrations in children with stable renal allograft function.

Cyclosporin A (CsA) has a narrow therapeutic window and necessitates monitoring of blood concentration. We aimed to evaluate trough (C0) and second hour (C2) level after ingestion of drug monitoring in renal allograft recipients. In this retrospective study, 12 children eight boys and four girls; mean age at transplantation 14.6 +/- 3.7 yr (ranges: 7.0-19.0), mean age post-transplant 17.8 +/- 4.9 yr (ranges: 9.0-24.0) who were transplanted >6 months were enrolled in this evaluation. Ten were recipients of a living related donor and two deceased donor grafts. While six children were receiving CsA, steroids and azathioprine, the other six received CsA, steroids and mycophenolate mofetil. Clinical course, blood pressure, renal and liver function tests were recorded. Mean C0 and C2 were 96.2 +/- 59.5 and 504 +/- 305.4 ng/mL respectively. Mean serum creatinine level was 1.2 +/- 0.45 mg/dL and mean creatinine clearance (CrCl) was 89.2 +/- 36.8 mL/min/1.73 m2. There was a correlation between serum creatinine level, CsA dose and C2 levels,whereas,there was no correlation between age, blood pressure, CrCl and C2 levels. However, no correlation was found between C0 levels and any of the above parameters. In conclusion, our data suggest that C2 levels are correlated better with dose and serum creatinine level.

Adolescent↗

Apoptosis and proliferation in childhood acute proliferative glomerulonephritis.

Acute proliferative glomerulonephritis is characterized by glomerular hypercellularity that can be caused by many different etiologies and pathogenetic mechanisms. A balance between cell birth by mitosis and cell death by apoptosis is crucial. In this study, apoptosis and the regenerative activity (Ki67/apoptosis index) were investigated in acute proliferative glomerulonephritis. Thirty-five children with biopsy-proven acute proliferative glomerulonephritis and five controls with MCD were studied retrospectively. According to the clinical outcome, patients were divided into 2 groups: group 1 (n =21) were patients with normal renal functions at follow-up; group 2 (n =8) were patients with end-stage renal failure or those who died. Immunohistochemical staining of proliferating cells (Ki67) was done. In situ end labeling of DNA was used to evaluate apoptosis. Glomerular cell apoptosis was 45% in the patients with acute proliferative glomerulonephritis and 3% in controls ( p <0.001). Apoptotic cells were identified in the tubulointerstitial compartment with higher and heavier immunostaining in patients than controls (p =0.001). Tubular proliferative index (= tubular proliferation/tubular apoptosis ratio) was significantly higher in group 1 patients than in group 2 patients (2.03+/-2% versus 0.32+/-0.6%, p =0.002). Tubulointerstitial regenerative ratio (=tubular proliferation/interstitial proliferation ratio) was significantly higher in controls than in patients (3.4+/-1.9 versus 1.52+/-0.8, p =0.01). In addition, it was significantly increased in group 1 patients when compared with those in group 2 patients (1.89+/-0.8 versus 0.73+/-0.2, p =0.001). Since 17 patients presented with postinfectious proliferative glomerulonephritis, which is known to exhibit better course, we also evaluated those parameters in patients with postinfectious proliferative glomerulonephritis separately. We found statistically significant differences only in the tubulointerstitial regenerative ratio, which was higher in postinfectious cases when compared with those in other cases [1.60 interquartile range (IQR) 1.54 versus 1.22 IQR 1.26, respectively, p =0.003]. In conclusion, tubular proliferative index and tubulointerstitial regenerative ratio might be useful parameters for predicting final functional outcome in acute proliferative glomerulonephritis. Further studies, however, are still needed to clarify the importance of these histopathological parameters.

Acute Disease↗

Chronic peritoneal dialysis in Turkish children: a multicenter study.

Chronic peritoneal dialysis (CPD) has been utilized in the treatment of children since 1989 in Turkey. The aims of this study were to summarize our experience with CPD in children and to establish a pediatric registry data system in Turkey. Standard questionnaires were sent to all pediatric CPD centers. 514 patients treated between 1989 and 2002 in 12 pediatric centers were enrolled in the study. Reflux nephropathy was the most common (18.1%) cause of renal failure. Mean age at dialysis initiation was 10.1+/-4.6 years. Mean duration of dialysis was 24.1+/-20.5 months. Continuous ambulatory peritoneal dialysis (CAPD) was the first CPD modality for 476 (92.6%) patients, 142 of whom switched to automated peritoneal dialysis (APD) during follow-up. Currently, 47.3% of the patients are still on CPD, 15.4% were transplanted, 13.2% switched to hemodialysis, 16.7% died. The patient and technique survivals were 90% and 95% at one year and 70% and 69% at five years, respectively. The survival was significantly shorter in the youngest age group (0-24 months) compared to those in older age groups (p=0.000). We herein report the first results of the TUPEPD study providing information on demographic data and survival of pediatric CPD patients. As opposed to clear recommendations in favor of APD, there is a clear preponderance of CAPD in our pediatric CPD population. That vesicoureteral reflux (VUR) is still the leading cause of renal failure is a distressing finding. Remarkably lower survival rates and transplantation ratios are as striking and distressing as the high incidence of VUR among the causes of ESRD. We conclude that we must make a great effort to achieve better results and to change these undesirable events.

Adolescent↗

Direct adsorption of lipoproteins from whole blood by direct adsorption of lipoprotein apheresis: first experience in two hypercholesterolemic children.

Low density lipoprotein (LDL) cholesterol apheresis, combined with lipid lowering drugs, provides a safe and effective means of improving the prognosis of patients with homozygote familial hypercholesterolemia, especially if started before the age of seven. The direct adsorption of lipoprotein (DALI) is the first extracorporeal low density lipoprotein removing system compatible with whole blood. The purpose of the present study was to clarify the efficacy and safety of DALI in children with homozygous familial hypercholesterolemia. Two boys, aged 9 and 15 years, with familial hypercholesterolemia, who were highly resistant to dietary regimes and to drug therapy, were treated with the low density lipoprotein adsorber DALI apheresis once every 2 weeks for 24 weeks. The treated blood volumes for each procedure were 2911 mL (493 +/- SD) and 5982 mL (1129 +/- SD), respectively. In our patients, the acute mean LDL cholesterol reductions were 44.7 +/- 8.9% and 58.8 +/- 4.5%. The corresponding reductions were 42.5 +/- 7.2% and 56 +/- 4.3% for total cholesterol, and 46.5 +/- 17.1% and 55 +/- 7.5% for very low density lipoprotein cholesterol (VLDL-C). There were insignificant losses of high density lipoprotein (12.2 +/- 5.7%, 8.3 +/- 5.5%). Treatment was well tolerated in general, and neither patient suffered from irreversible or long-lasting adverse effects. Our experience with DALI apheresis is encouraging. The present report is the first on the use of DALI in children. Based on this short-term evaluation we think that DALI might be safe and effective in children with homozygote familial hypercholesterolemia, however further evaluation of long-term effects is needed.

Adolescent↗

The significance of IgA class of antineutrophil cytoplasmic antibodies (ANCA) in childhood Henoch-Schönlein purpura.

Antineutrophil cytoplasmic antibodies (ANCA) have been identified in a wide variety of vasculitic disorders, but it is controversial whether ANCA are present in the sera of patients with HSP. This prospective study was designed to assess the place of ANCA, particularly their IgA subclass, in HSP. Thirty-five patients (18 boys, 17 girls) aged 9.4 +/- 4 (3-16) years with a clinical diagnosis of HSP based on American College of Rheumatology (ACR) criteria were enrolled. Thirteen patients (6 boys, 7 girls) aged 8.3 +/- 5.5 (2-21) years with other vasculitides, consisting of classic polyarteritis nodosa (PAN) (n = 2); cutaneous polyarteritis nodosa (n = 1); acute infantile hemorrhagic edema (n = 2); acute urticarial vasculitis (n = 2); hypocomplementemic vasculitis (n = 1); and unclassified vasculitis (n = 5) served as disease controls and 10 healthy children served as normal controls. Twenty-five HSP patients and 7 disease controls were re-evaluated in the resolution phase that was described as 4-6 weeks after all symptoms subsided and all medications were stopped. Blood samples for ANCA and IgA rheumatoid factor (RF) were studied by indirect immunofluorescence (IIF) and ELISA, respectively. IgG ANCA was significantly lower in percentage in HSP patients (2.8%) than in disease controls (40%) (p = 0.002). In contrast, IgA ANCA in cytoplasmic pattern was detected in a significantly higher percentage of HSP patients (82.3%) in the acute phase compared to those in the disease controls (38%) (p = 0.004). In the resolution phase, IgA ANCA was negative in 88% of the patients (p = 0.001 for acute vs resolution phases). Neither IgG nor IgA ANCA were seen in normal controls. No relationship was found between disease severity of HSP and IgA ANCA. Positive IgA rheumatoid factor was present in only two patients with HSP. In conclusion, our results suggest that IgA ANCA may be useful to confirm the diagnosis of HSP in children.

Adolescent↗

Monocyte chemoattractant protein-1 and interleukin-8 levels in children with acute poststreptococcal glomerulonephritis.

The infiltration of leukocytes into the glomeruli is a major factor in inflammatory glomerular damage in acute poststreptococcal glomerulonephritis (APSGN). Chemokines participate in leukocyte infiltration. The aim of the present study was to investigate the role of monocyte chemoattractant protein-1 (CCL2/MCP-1) and interleukin-8 (CXL8/IL-8) in APSGN with special emphasis on their role in the clinical course of renal disease. Twenty-one children with APSGN were studied. Serum and urinary CCL2/MCP-1 and CXL8/IL-8 levels were measured by ELISA. The relationships between urinary chemokines and the degree of proteinuria were investigated. Serum and urinary CCL2/MCP-1 levels were significantly higher in the acute phase than in the resolution phase and in controls ( P<0.05). Urinary CCL2/MCP-1 levels in the control group were significantly lower than in both the acute and resolution phases ( P=0.01 and P =0.001, respectively). In the acute phase, urinary CCL2/MCP-1 correlated with the extent of proteinuria ( r=0.58, P =0.006) but not with serum CCL2/MCP-1 levels ( r=0.21, P =0.36). Urinary and serum CXL8/IL-8 levels were significantly elevated in the acute phase compared with the resolution phase and controls ( P<0.05). A consistent increase in urinary CCL2/MCP-1 was found in the acute phase of patients with APSGN, and this correlates with the degree of proteinuria. Our results emphasize the important role of locally produced chemokines in immune-mediated glomerular injury.

Acute Disease↗

An unusual cause of acute renal failure: renal lymphoma.

Renal involvement is a common finding in non-Hodgkin's lymphoma (NHL). Acute renal failure at initial presentation due to lymphomatous infiltration of the kidneys has been described infrequently. We report a 17-year-old male who presented with acute renal failure due to massive lymphomatous infiltration of the kidneys, which necessitated hemodialysis. The diagnosis of B-cell NHL was established by tru-cut biopsy of the kidneys and the patient had an excellent response to high-dose chemotherapy with no major complication. The presence of extrarenal involvement in the testes and the retroperitoneal lymph nodes made the diagnosis of primary renal lymphoma debatable. However, considering the delay in diagnosis and the high proliferative rate of B-cell NHL, we might postulate that the disease had originated primarily in the kidneys. We recommend that in NHL cases with severe renal involvement, full-dose chemotherapy should be instituted with meticulous clinical and laboratory follow-up in order to improve clinical and renal failure status rapidly and to avoid further dissemination of NHL.

Acute Kidney Injury↗

Effects of pentoxifylline in adriamycin-induced renal disease in rats.

Tumor necrosis factor-alpha (TNF-alpha) is a mediator of inflammation in human and animal renal disease. Pentoxiphylline (PTX) is an inhibitor of TNF-alpha. In this study we examined the effects of PTX on TNF-alpha, proteinuria, nitrite production, and apoptosis in an experimental model of Adriamycin (ADR) nephropathy in rats. Rats were divided into four groups: untreated Wistar rats (controls), PTX treatment alone, ADR treatment alone to induce nephropathy, and ADR treatment followed by PTX. ADR treatment followed by PTX treatment prevented the increase in serum TNF-alpha levels and proteinuria in rats with ADR-nephropathy ( P<0.05). Urine nitrite levels were significantly increased in the ADR-induced nephropathy group and the increase was prevented in the ADR-induced nephropathy group when they also received PTX. The urine nitrite levels were not different between the PTX-treated group and the untreated control rats. PTX prevented the rise of serum TNF-alpha in ADR nephropathy rats and a decrease in proteinuria, urine nitrite, and apoptosis in the renal tissue. These findings suggest a beneficial anti-inflammatory effect of PTX.

Animals↗

Juvenile polyarteritis: results of a multicenter survey of 110 children.

OBJECTIVE: To characterize pediatric patients who had been diagnosed with polyarteritis nodosa (PAN) through necrotizing vasculitis of the small and mid-size arteries or those with characteristic findings on angiograms data were collected. STUDY DESIGN: Pediatricians were asked to classify their patients into one of the four suggested groups for juvenile PAN. Twenty-one pediatric centers worldwide participated with 110 patients. RESULTS: The girl:boy ratio was 56:54, with a mean age of 9.05 +/- 3.57 years. The cases were classified as: 33 (30%) cutaneous PAN; 5 (4.6%) classic PAN associated with hepatitis B surface antigen (HBs Ag); 9 (8.1%) microscopic polyarteritis of adults associated with antineutrophil cytoplasmic antibodies (ANCA); and 63 (57.2%) systemic PAN. Cutaneous PAN was disease confined to the skin and musculoskeletal system. All patients with HBs Ag-associated classic PAN were diagnosed with renal angiograms. Antiviral treatment was administered in most cases. Microscopic PAN patients had pulmonary-renal disease, in combination or separately. ANCA was present in 87%, and 2 patients progressed to end-stage renal failure. Patients classified with systemic PAN had multiple system involvement, almost all had constitutional symptoms, and all had elevated acute phase reactants. Corticosteroids and cyclophosphamide were the first choices of immunosuppressive treatment. The overall mortality was 1.1%. CONCLUSIONS: There were remarkable differences among pediatric patients with PAN, with different clinical manifestations and overall better survival and lower relapse rates when compared with adults.

Adolescent↗

Beneficial role of intravenous calcitriol on bone mineral density in children with severe secondary hyperparathyroidism.

OBJECTIVES: In this prospective study, the effect of calcitriol therapy on bone mineral density and osteopenia in patients with severe secondary hyperparathyroidism has been investigated. MATERIALS AND METHODS: The study was carried out on 24 chronic dialysis patients consisting of 13 boys and 11 girls, aged between 8-18 years. Patients were divided into 3 groups according to the severity of hyperparathyroidism and therapy regimens. Group I consisted of 5 patients with normal parathormon levels who did not receive calcitriol therapy. In group II and III, there were patients with secondary hyperparathyroidism. Group II consisted of 10 patients receiving oral calcitriol therapy. Group III consisted of 9 patients receiving intravenous (i.v.) calcitriol. Bone mineral density was measured by dual energy x-ray absorptiometry. Osteopenia was defined as a Z-score worse than -2. Bone mineral density was assessed as baseline and at the end of one year. RESULTS: A significant improvement was observed in Z-score in the group III whereas the mean value of Z-score tended to be worse in group I and it was not significantly different in group II from the initial values. The better Z-score in group III was associated with more effective stabilization of alkaline phosphatase level and bone specific alkaline phosphatases (BAP) concentrations. CONCLUSION: Significant improvement of Z-score in group III suggested the beneficial role in i.v. administration of calcitriol in chronic dialysis patients.

Administration, Oral↗