Galactose-Deficient IgA1 B cells in the Circulation of IgA Nephropathy Patients Carry Preferentially Lambda Light Chains and Mucosal Homing Receptors.

BACKGROUND: IgA nephropathy (IgAN) primary glomerulonephritis is characterized by the deposition of circulating immune complexes composed of polymeric IgA1 molecules with altered O-glycans (Gd-IgA1) and anti-glycan antibodies in the kidney mesangium. The mesangial IgA deposits and serum IgA1 contain predominantly λ light (L) chains, but the nature and origin of such IgA remains enigmatic. METHODS: We analyzed λ L chain expression in peripheral blood B cells of 30 IgAN patients, 30 healthy controls (HCs), and 18 membranous nephropathy patients selected as disease controls (non-IgAN). RESULTS: In comparison to HCs and non-IgAN patients, peripheral blood surface/membrane bound (mb)-Gd-IgA1+ cells from IgAN patients express predominantly λ L chains. In contrast, total mb-IgA+, mb-IgG+, and mb-IgM+ cells were preferentially positive for kappa (κ) L chains, in all analyzed groups. Although minor in comparison to κ L chains, λ L chain subsets of mb-IgG+, mb-IgM+, and mb-IgA+ cells were significantly enriched in IgAN patients in comparison to non-IgAN patients and/or HCs. In contrast to HCs, the peripheral blood of IgAN patients was enriched with λ+ mb-Gd-IgA1+, CCR10+, and CCR9+ cells, which preferentially home to the upper respiratory and digestive tracts. Furthermore, we observed that mb-Gd-IgA1+ cell populations comprise more CD138+ cells and plasmablasts (CD38+) in comparison to total mb-IgA+ cells. CONCLUSIONS: Peripheral blood of IgAN patients is enriched with migratory λ+ mb-Gd-IgA1+ B cells, with the potential to home to mucosal sites where Gd-IgA1 could be produced during local respiratory or digestive tract infections.

Nephrotoxicity of calcineurin inhibitors as a risk factor for BK polyomavirus replication after kidney transplantation.

BK polyomavirus-associated nephropathy (PyVAN) is responsible for a significant percentage of transplanted kidneys prematurely terminating their function. Its occurrence is closely related to the intensity of immunosuppressive therapy. In a group of 161 newly transplanted patients, we prospectively evaluated 457 protocol renal biopsies performed within the first year after transplantation. Using the calcineurin inhibitors (CI) nephrotoxicity score, the incidence of nephrotoxicity was monitored as a manifestation of excessive immunosuppression. Findings were correlated with clinical evidence of active BK polyomavirus (BKPyV) replication and PyVAN. Compared to the normal histology, nephrotoxicity was associated with more frequent BKPyV viremia and viruria (p = .01 and p < .01, respectively) and more common occurrence of PyVAN. The persistence of toxicity in the subsequent biopsy proved to be a negative risk factor of viremia and viruria (p = .03 and p < .01, respectively), independently of the initial BKPyV status. Toxicity could also be used as a predictor of viremia and viruria (p = .04 and p < .01, respectively) even in the absence of viral replication at the time of initial biopsy. The early histological manifestation of CI nephrotoxicity was associated with significant BKPyV reactivation in the risky first posttransplant year.

Arteriovenous Grafts' Types of Indications and Their Infection Rate.

BACKGROUND: Arteriovenous graft infection is a well-known and frequent complication. The objective of this study was to compare infection rates of primary and secondary indicated arteriovenous grafts (AVGs). SUBJECTS AND METHODS: Retrospectively, we evaluated the indications for AVGs created at our institution which became infected. One hundred forty AVGs were evaluated. Of these AVGs, 33 (23.6%) were primary and 107 (76.4%) secondary indicated. RESULTS: Infection of a primary AVG was detected in 5 patients (15.2 %). Infection of a secondary AVG was detected in 30 patients (28.0%). Primary and secondary patency were significantly lower in patients with infected AVG (P = 0.006; P = 0.0001). The effect of diabetes mellitus and age on development of infection was not confirmed. CONCLUSIONS: Indications for AVG creation clearly influence the future risk of infection. If the indication to use the AVG is to correct a complicated arteriovenous fistula, the risk of infection is 2 times higher.

Association of serum adipocyte fatty acid-binding protein and apolipoprotein B /apolipoprotein A1 ratio with intima media thickness of common carotid artery in dyslipidemic patients.

BACKGROUND: Diseases caused by atherosclerosis play the most important role in mortality and morbidity worldwide. Serum adipocyte fatty acid binding protein (A-FABP) seems to be a new promising marker to determine the risk of atherosclerosis. OBJECTIVE: The aim of this study was to evaluate relationships between serum A-FABP levels in studied individuals and to assess the possibility of modeling the intima media thickness of the common carotid artery (C-IMT) using A-FABP levels and other observed characteristics. METHODS: Seventy two Caucasian individuals were enrolled and divided into 3 groups: dyslipidemic patients with or without metabolic syndrome (MetS+, n=17; MetS-, n= 34) and controls (n=21). RESULTS: There was confirmed the well-established risk profile of individuals with MetS (unfavorable lipid and lipoprotein profile, as well as increased parameters of insulin resistence and C-IMT). A-FABP concentrations in this group were significantly higher in comparison with both MetS- and controls. CONCLUSION: Using multiple linear regression models of C-IMT values for all individual data, healthy controls and dyslipidemic patients without metabolic syndrome (MetS-) A-FABP levels were not revealed as an important predictor of C-IMT in our model. In contrast, age, gender, waist circumference, nonHDL cholesterol levels and ApoB/ApoA1 ratio were important repressors of C- IMT in study individuals. This finding may be attributed to the overwhelming effect of other more robust risk factors for atherosclerosis in these individuals.

Late Rupture of Lumbar Artery as an Unusual Complication after Renal Biopsy - Case Report.

The most serious complication of renal biopsy is vascular damage with subsequent haemorrhage. To our knowledge, we present a first ever case of lumbar artery (LA) rupture accompanied by massive retroperitoneal bleeding, which developed after a significant amount of time following the biopsy itself. In a 63-year-old Caucasian female patient, a percutaneous left kidney biopsy was performed under continuous ultrasound guidance. On the fourteenth day after the procedure, she was examined for a sudden onset of left lumbar region pain. Computed tomography angiography showed a large retroperitoneal hematoma with active bleeding from the fourth left LA. Successful endovascular superselective embolization was performed immediately. The predisposing factor for the late haemorrhage could have been anticoagulation therapy, renal insufficiency and older age. Our case report highlights the need for caution, especially when performing kidney biopsy in a group of high-risk patients, particularly if they are indicated for subsequent anticoagulant therapy.

Emergency surgical treatment of complicated acute pancreatitis after kidney transplantation with acute rejection: Case report and literature review.

INTRODUCTION: Acute pancreatitis is a rare but frequently fatal complication in patients following kidney transplantation. The first case of acute pancreatitis in patients following a kidney transplant was described by Starzl in 1964. The incidence of acute pancreatitis is stated at between 1 and 5%. The mortality rate amongst these patients reaches as high as 50-100%. PRESENTATION OF CASE: Here we present a case of acute pancreatic abscess in a caucasian female - shortly following a kidney transplant complicated by the development of acute rejection, in which immunosuppressant therapy is a potential etiological agent. Emergency surgical treatment was indicated, which included drainage of the abscesses irrigation of the abdominal cavity. Immunosuppressive medication was considered a possible etiological factor, and as a result administration of tacrolimus and mycophenolate mofetil was discontinued. This was successful and three months later, diagnostic rebiopsy of the graft was performed without signs of rejection. DISCUSSION: The etiology of this illness is multifactorial. The clinical manifestation of acute pancreatitis in patients following kidney transplantation is the same as in the remainder of the population. However, in patients following transplantation with long-term immunosuppression, it usually manifests a more rapid development and a more severe, frequently fatal course. CONCLUSIONS: With regard to the patient's comorbidities, early surgical therapy was indicated - drainage and closed lavage and immunosuppressive medication as a suspected tobe ethiological factor was discontinued. This course of treatment led to a complete recovery with preservation of good function of the cadaverous kidney.

Cutaneous bacillary angiomatosis due to Bartonella quintana in a renal transplant recipient.

Bacillary angiomatosis (BA) is a disorder of neovascular proliferation involving skin and other organs of immunosuppressed patients caused by Bartonella species. BA has been recognized in both immunocompetent and immunodeficient patients, mostly in human immunodeficiency virus (HIV)-infected persons, much more rare in those with other immunodeficiencies, including organ transplantation. Diagnosis is based on serologic analysis, culture and molecular biology [detection of Bartonella species deoxyribonucleic acid (DNA) in tissue biopsy extracts by real-time polymerase chain reaction (PCR)]. All immunosuppressed patients with BA should be treated with antibiotics because of potentially life-threatening course of the disease. We report the first case of cutaneous bacillary angiomatosis due to Bartonella quintana in renal transplant recipient. This presentation demonstrates that BA should be considered a differential diagnosis in immunocompromised patients presenting with fever and cutaneous angioma-like lesions.

Prehypertension in dyslipidemic individuals; relationship to metabolic parameters and intima-media thickness.

INTRODUCTION: Like hypertension, prehypertension is associated with cardiovascular disease. AIMS: The aim of this study was to evaluate: a) the prevalence of prehypertension/hypertension in individuals with various dyslipidemic phenotypes; b) the relation between blood pressure (BP) and other risk factors for atherosclerosis; c) atherogenic potential of prehypertension by the assessment of intima-media thickness of the arteria carotis communis (IMT). METHODS: 667 clinically asymptomatic subjects were divided into four dyslipidemic phenotypes (DLP) according to apolipoprotein B (apoB) and triglycerides (TG): DLP1 (n=198, normo-apoB/normo-TG), DLP2 (n=179, normo-apoB/hyper-TG), DLP3 (n=87, hyper-apoB/normo-TG), DLP4 (n=203, hyper-apoB/hyper-TG). DLP1 served as a control group. RESULTS: There was significantly higher prevalence of prehypertension and hypertension in subjects with dyslipidemia (DLP2 43.0%, 41.3%; DLP3 42.5%, 29.9%; DLP4 42.4%, 47.8%) than in normolipidemic individuals (DLP1 32.8%, 20.2%). Systolic and diastolic blood pressure (SBP + DBP) correlated with age, total cholesterol, TG, non-HDL-cholesterol, body mass index and waist circumference; SBP additionally with C-peptide, fasting glycemia; DBP additionally with apoB, homeostasis model assessment (HOMA) and plasminogen activator inhibitor-1. The IMT of hypertensive and of prehypertensive subjects was higher than that of subjects with normal BP in all DLPs. CONCLUSIONS: The prevalence of prehypertension was higher in all dyslipidemic patients. The common prevalence of prehypertension/hypertension was highest in the hypertriglyceridemic subjects. Prehypertensive and hypertensive patients had higher IMT than normotensive individuals in all DLPs.

Relationship between serum adipocyte fatty acid-binding protein and endothelial/hemostatic markers in dyslipidemic subjects.

OBJECTIVES: Some findings support the role of serum adipocyte fatty acid-binding protein (A-FABP) as a key pro-inflammatory mediator that links obesity with cardiovascular diseases. The aim of the study was to evaluate the association of A-FABP with endothelial/hemostatic markers [von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), tissue-plasminogen activator (t-PA), soluble intercellular cell adhesion molecule-1 (s-ICAM-1) and soluble vascular cell adhesion molecule-1 (s-VCAM-1)] in asymptomatic dyslipidemic subjects. DESIGN: We examined 105 dyslipidemic patients (with apolipoprotein B concentration ≥1.2 g/l and/or triglyceride (TG) concentration ≥1.5 mmol/l) without clinical manifestation of atherosclerosis and 50 normolipidemic healthy subjects, who served as a control group. Except of endothelial/hemostatic markers, anthropometric and lipid parameters, markers of insulin resistance and inflammation were assessed. RESULTS: In dyslipidemic patients, A-FABP positively correlated with age (p<0.05), TG (p<0.05), insulin (p<0.05), homeostatic model assessment (HOMA) index (p<0.05), body mass index (p<0.001), waist circumference (p<0.05), high sensitivity C reactive protein (p<0.01), and vWF (p<0.05) and negatively with male gender (p<0.05). There were no correlations between A-FABP and PAI-1, t-PA, s-VCAM-1 or s-ICAM-1. By using linear multivariate regression analysis the positive association between A-FABP and vWF was independent of age, gender, insulin resistance, and visceral obesity. CONCLUSION: Study displayed an independent positive association of A-FABP with vWF in clinically asymptomatic dyslipidemic subjects. Contribution of A-FABP in the process of endothelial dysfunction could help to explain the role of obesity in cardiovascular damage.

Experimental approaches to studies on drug metabolism and drug interactions in man: interaction of acyclic nucleoside phosphonates with human liver cytochromes P450 and flavin-containing monooxygenase 3.

OBJECTIVES: To determine a possible influence of acyclic nucleoside phosphonates on FMO3 and CYP activity at molecular level in vitro. METHODS: Inhibition of individual CYP and FMO3 activities in the reconstituted system and in artificial membranes (bactosomes) was studied. RESULTS: Activity of FMO3 was inhibited by PMPA and bisPOC-PMPA even at low levels of these drugs (below 100 microM). In reconstituted system with CYP2C9, no inhibition of CYP2C9 activity was observed. On the other hand, experiments based on membrane coexpressed system showed a modest extent of inhibition (for PMEA, PMPA, bisPOM-PMEA and bisPOC-PMPA the level of inhibition was 77.8%; 74.1%; 64.2% and 68.6%, respectively at 400 microM). CONCLUSIONS: PMPA and bisPOC-PMPA are able to inhibit FMO3 activity at relatively low levels (10-100 microM) indicating a relatively specific interaction. Activity of CYP2C9 was affected when using the membranes coexpressed with NADPHcytochrome P450 reductase. This is probably due to more natural conditions for maintaining the CYP activity in bacterial membranes. As the inhibitor concentration in the systemic circulation does not exceed 2 microM, the probability of a significant in vivo effect of adefovir, tenofovir and the respective prodrugs on the microsomal system of cytochromes P450 and FMO3 is relatively low.