Ilona Kurnatowska

Serum osteoprotegerin is a predictor of progression of atherosclerosis and coronary calcification in hemodialysis patients.

Background: The aim of this prospective cohort study was to evaluate the progression of coronary artery calcification (CAC), and atherosclerosis in hemodialysis (HD) patients and to relate them to novel biomarkers, i.e. serum osteoprotegerin (OPG) and fibroblast growth factor 23 (FGF-23). Material and Methods: Forty-seven HD patients were followed up for 30 months or until death. Intima media thickness (CCA-IMT), atherosclerotic plaques and CAC were assessed at baseline and after 30 months. Serum mineral parameters, lipids, OPG and plasma FGF-23 were also measured. Results: At baseline, 70% HD patients presented detectable CAC. The patients without calcification at baseline remained calcification free at 30 months and presented lower serum OPG and FGF-23 than those with CAC. A 64.4% progression of CAC was observed in all patients with CAC at baseline. In parallel, a 13% increase in CCA-IMT was found. Both ΔCAC and ΔCCA-IMT correlated positively with baseline and follow-up serum OPG. The patients who died had significantly higher baseline CAC and serum OPG. Conclusion: The plasma level of OPG could serve as a surrogate marker of progression of atherosclerosis and calcification in patients with end-stage renal disease. Therefore, the serum OPG may be a candidate biomarker of cardiovascular complications and poor outcome among dialysis patients.

Tight relations between coronary calcification and atherosclerotic lesions in the carotid artery in chronic dialysis patients.

Aim:  Both vascular calcification and atherosclerosis are highly prevalent in patients with end‐stage renal disease (ESRD) and have been associated with increased cardiovascular morbidity. Because those two phenomena might be only coincidentally related in chronic haemodialysis (HD) patients, in this study, coronary artery calcification (CAC), common carotid artery intima media thickness (CCA‐IMT) and thickness of atherosclerotic plaques in the carotid artery were simultaneously measured.

Trends in the Incidence of Biopsy-Proven Glomerular Diseases in the Adult Population in Central Poland in the Years 1990-2010

Background: There is a paucity of epidemiological data on biopsy-proven glomerulonephritis (GN) in Poland. The aim of this study was to assess the epidemiology of renal diseases based on histological diagnosis in the region of Central Poland over the last two decades. Methods: Retrospective analysis of the results of 746 consecutive native kidney biopsies performed in the Caucasian adults from 1990 to 2010 in a single tertiary nephrology center serving an area of Central Poland. Results: Primary GN was found in 81.4% of all biopsies. The mesangioproliferative GN including IgA nephropathy was the most frequent type of primary GN (51.2%). Membranoproliferative GN was diagnosed between 1990 and 2000 more frequently than in the following decade (26.7 vs. 7.3%, p < 0.001). There was a significant increase in the incidence of FSGS (4.8 vs. 17.3%, p < 0.001) and MCD (5.1 vs. 11.2%, p < 0.001) over time. Secondary GN was documented in 18.6% of biopsies and lupus nephritis was the most frequent cause (34.5%). Conclusion: Our analysis showed the decrease in the incidence of membranoproliferative GN with the parallel increase of FSGS and MCD over the last twenty years. Mesangioproliferative GN including IgA nephropathy remains the most frequent type of GN observed in our region.

Detection of transplant renal artery stenosis in the early postoperative period with analysis of parenchymal perfusion with ultrasound contrast agent.

BACKGROUND Transplant renal artery stenosis (TRAS) is a serious vascular complication due to non-specific clinical manifestations, causing serious diagnostic difficulties. Contrast-enhanced ultrasound (CE-US) can complement standard sonographic examination in evaluation of TRAS. MATERIAL AND METHODS Standard ultrasound B presentation, extended with color Doppler assessment of the flow spectrum and CE-US, was carried out in the early postoperative period in a group of 180 patients who underwent kidney transplantation. In CE-US analysis, the maximum contrast agent perfusion to the cortex and renal pyramids was evaluated. In 15 patients with sonographically diagnosed TRAS, magnetic resonance angiography and computer tomography angiography were performed to confirm the diagnosis. RESULTS In patients with TRAS, significantly longer time of contrast agent (CE) inflow was observed in comparison to patients without perfusion disturbances (3.47 s vs. 1.5 s, p<0.000 for cortex; 6.01 vs. 2.09 s for pyramids, p<0.000). The rate of CE inflow was strongly positively correlated with severity of stenosis assessed on the basis of CTA/MRA examination (R=0.97 for cortex and 0.9 for pyramids; p<0.001). Six months after kidney transplantation, patients with a history of TRAS had significantly higher serum creatinine level than recipients with normal renal artery blood flow (1.76 mg/dL vs. 1.53 mg/dl, p<0.02). Estimated GFR was decreased to 35.9 ml/min vs. 46.5 ml/min, respectively (p<0.05). CONCLUSIONS Contrast-enhanced ultrasound allows for quick and non-invasive assessment of parenchymal kidney graft perfusion. It enables confirmation of TRAS diagnosis in the early postoperative period and helps assess the degree of stenosis.

Plasma Desphospho-Uncarboxylated Matrix Gla Protein as a Marker of Kidney Damage and Cardiovascular Risk in Advanced Stage of Chronic Kidney Disease

Background/Aims: Desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) is formed as a result of vitamin K insufficiency. The aim of this study was to investigate the association between plasma dp-ucMGP, kidney function and cardiovascular risk factors before and after 9-months substitution of vitamin K2 in non-dialysis patients with chronic kidney disease (CKD) stage 4 and 5. Methods: 38 CKD patients were supplemented for 270±12 days with 90 µg vitamin K2 and 10 µg cholecalciferol or 10 µg cholecalciferol alone. At baseline and at follow-up circulating calcium, phosphate, lipids, hemoglobin, albumin and total protein, dp-ucMGP, osteoprotegerin, fetuin A, osteocalcin and fibroblast grown factor 23 (FGF-23) were assessed. Proteinuria was assessed in the first morning void. Results: Baseline plasma dp-ucMGP was 1018.6±498.3 pmol/l and was significantly higher in patients at stage 5 CKD (1388.3 ±505.4 pmol/l) than at stage 4 (885.1±419.7 pmol/l), p=0.04. Vitamin K2 supplementation resulted in a decrease of dp-ucMGP level by 10.7%. Plasma dp-ucMGP was positively associated with proteinuria, serum creatinine, PTH and FGF-23; and inversely associated with glomerular filtration rate, serum hemoglobin and albumin. Conclusions: High dp-ucMGP level, reflecting a poor vitamin K status seems to be associated with kidney damage and may be also a marker of cardiovascular risk in CKD patients. Supplementation with vitamin K2 may improve the carboxylation status of MGP.

Guillain-Barré syndrome in the course of EBV infection after kidney transplantation--a case report.

BACKGROUND Neurological complications are quite frequent in patients after solid organ transplantation, mostly affecting the central nervous system, and less frequently the peripheral nerves. Guillain-Barré syndrome (GBS), a reactive autoimmune disease of the nervous tissue, is the most common cause of acute polyneuropathy in adults following a viral or bacterial infection. GBS has been also linked to neurotoxic adverse effects of calcineurin inhibitors. This syndrome occurs relatively frequently in patients after bone marrow transplantation, but has been a rare complication in solid organ transplant recipients. Epstein-Barr virus (EBV) infection is relatively common in transplant recipients and in some cases may lead to neurological complications. CASE REPORT In this report we present an interesting case of a patient who developed GBS in the course of EBV infection 1 year after kidney transplantation. CONCLUSIONS In patients with rapid development of polyneuropathy after transplantation, Guillain-Barré syndrome should be excluded.

Prevalence of arterial hypertension and the number and classes of antihypertensive drugs prescribed for patients late after kidney transplantation

BACKGROUND There are limitations of the use of several classes of antihypertensive drugs in patients after kidney transplantation (KTx), as well as contradictory opinions on their effects on progression of graft dysfunction. In this study we assessed the prevalence of arterial hypertension (HA) and the antihypertensive agents used by the patients long after KTx. MATERIAL/METHODS This retrospective evaluation of the number and classes of antihypertensive drugs was based on medical records of 348 patients (140 F, 208 M; mean age 49 ± 13 years) late after KTx (mean time after KTx 78 ± 43 months). The data were related to graft function. RESULTS Ninety-three percent of patients after KTx required antihypertensive therapy. Only 8.7% were treated with 1 agent (mean eGFR 65.1 ± 27.4 ml/min), 26.3% received 2 drugs (eGFR 60.0 ± 25.8 ml/min), 34.2% received 3 drugs (eGFR 55.5 ± 23.4 ml/min), 20.1% received 4 drugs (eGFR 54.9 ± 24.9 ml/min), and 10.5% received ≥ 5 drugs (eGFR 45.9 ± 22.0 ml/min). The number of antihypertensive medications increased along with the deterioration of graft function. Dihydropyridine calcium antagonists (CCB) were the most common class of drugs recommended to the patients after KTx (81%), followed by β-adrenergic antagonists (74.4%); α-antagonists (40.2%), angiotensin-converting enzyme inhibitors (38.7%), diuretics (34.1%), clonidine (17.8%) and angiotensin II receptor blockers (9.5%). CONCLUSIONS HA is highly prevalent in KTx patients. Multidrug therapy is usually required for the treatment of HA in this population. Dihydropyridine CCB is the most common class of antihypertensive drugs used by them. Graft function is a determining factor in the number of antihypertensive agents.

Two cases of severe de novo colitis in kidney transplant recipients after conversion to prolonged-release tacrolimus.

Diarrhea is a frequent complication in patients after solid organ transplantation. We describe two cases of severe new onset colitis in kidney transplant recipients that developed shortly after the introduction of the therapy with prolonged‐release formulation of tacrolimus replacing standard twice daily formulation of tacrolimus in one case and cyclosporine A in the second case. Both patients developed severe, intermittent bloody diarrhea with abdominal pain, weight loss, dehydration and worsening graft function that required immediate hospitalization. The symptoms did not diminish after dose reduction or withdrawal of mycophenolic acid derivatives. After excluding bacterial, viral, fungal, and parasite infections, colonoscopy with colonic biopsy was performed in both patients, which revealed features typical of colitis. Both patients received mesalazine until the symptoms stopped. In one of the patients, standard formulation of tacrolimus was immediately reintroduced. The second patient was given everolimus in an acute phase of diarrhea. Although the two cases presented in this report cannot fully support a causal relationship between the prolonged‐release tacrolimus and colitis, they should increase awareness among transplant physicians and prompt more close monitoring of such potential side effects as a part of the pharmacovigilance plan for a new formulation of the well‐established immunosuppressive drug.

Contrast‐enhanced sonography of postbiopsy arteriovenous fistulas in kidney grafts

To assess the usefulness of contrast‐enhanced ultrasonography (CE‐US) in the visualization of a kidney graft following a biopsy that was complicated by an arteriovenous fistula (AVF).

Perfusion Disturbances of Kidney Graft Parenchyma Evaluated with Contrast-Enhanced Ultrasonography in the Immediate Period following Kidney Transplantation

Purpose: Graft parenchyma perfusion disturbances (GPPD) in transplanted kidneys are common in the early postoperative period. Rapid and accurate diagnosis can guide proper treatment, preventing graft dysfunction. Methods: One hundred and eighty patients, who underwent kidney transplantation (KTx), were examined in the immediate postoperative period using real-time ultrasonography (B-mode) with color and power Doppler (US-CD/PD) and B-flow ultrasound, as well as with an additional protocol of contrast-enhanced ultrasonography (CE-US). Regions of GPPD were localized and measured. The number and size of these areas were compared between the two acquisition techniques. Follow-up examinations were carried out 6 months postoperatively. Results: CE-US revealed more GPPDs and showed them more precisely than the B+US-CD/PD/B-flow technique. Moreover, in the CE-US examination, ischemic foci had statistically significant higher echogenicity in comparison to normal parenchyma, were larger and better visualized (better circumscribed) than in B+US-CD/PD/B-flow. Conclusion: CE-US allows the visualization of GPPD caused by occlusion of small arteries. It is a noninvasive, safe, real-time method, which has many advantages over standard B+US-CD/PD/B-flow examinations, and we recommend it as a routine diagnostic procedure in the early postoperative period following KTx.