Jan Tencer

Stability of albumin, protein HC, immunoglobulin G, K- AND γ-chain immunoreactivity, orosomucoid and a 1-antitrypsin in urine stored at various conditions

Urine samples from 10 randomly selected patients with advanced renal disease were each divided into six aliquots and a preservative solution containing ben-zamidinium chloride, EDTA, tris(hydroxymethyl)-aminomethane and azide was then added to three of the aliquots. Aliquots with and without additive were then stored at room temperature for up to 7 days, at 4oC for up to 30 days and at -20 oC for up to 6 months. The concentrations of albumin, protein HC, IgG, orosomucoid and a 1-antitrypsin as well as the K- AND γ-chain immuno-reactivities in the samples were determined by automated immunoturbidimetry or by single radial immunodiffusion after 1, 3, 7, 14, 30, 90 and 180 days of storage. All investigated proteins, except α1-antitrypsin in native urine, were stable for 7 days in the samples stored at room temperature both in the presence and absence of additives. All investigated proteins, except a 1-antitrypsin in native urine, were stable for 30 days in the samples stored at 4oC both in the presence and a...

Analysis of proteinuria: reference limits for urine excretion of albumin, protein HC, immunoglobulin G, k- and Δ-immunoreactivity, orosomucoid and α1-antitrypsin

Efficient use of assessment of urine protein excretion in nephrological practice requires adequate reference intervals. To determine the upper reference limits of urine albumin, protein HC (α1-microglobulin), immunoglobulin G (IgG), orosomucoid (α1-acid glycoprotein), α1-antitrypsin, and k- and Δ-chain immunoreactivities, the concentrations of these proteins were measured in urine samples from 95 healthy, adult individuals, using rapid, generally available methods and with conditions for urine collection which secured stable protein levels. The obtained values were expressed inmgl−1, as the urine protein-creatinine index and as fractional protein-creatinine clearance.No differences were found between the upper reference limits in the first voided morning urine samples and the randomly collected urine samples, nor between the upper reference limits in urine samples collected from males and females. The urinary excretion of the tested proteins did not correlate to age, positive dipsticks for haematuria nor ...

Long-term Stability of Albumin, Protein HC, Immunoglobulin G, κ- and λ-chain-immunoreactivity, Orosomucoid and α1-antitrypsin in Urine Stored at -20°C

The stability of albumin, protein HC, immunoglobulin G, κ- and λ-chain immunoreactivity, orosomucoid and α1 -antitrypsin in urine stored at -20°C for up to 24 months was investigated. Significant decreases of the median concentration values for protein HC, IgG and α1-antitrypsin were observed for native urine. Addition to urine of a preservative solution containing benzamidinium chloride, EDTA, tris(hydroxymethyl)-aminomethane and azide prevented the decreases of the concentration values for protein HC and IgG but not for α1-antitrypsin. The median concentration values for albumin, orosomucoid and κ-and λ-chain immunoreactivity did not change significantly upon storage of native urine, nor for urine with the preservative solution.

Asymptomatic Bacteriuria—A Long-Term Study

Four percent of the women in a population study 1969-1970 had asymptomatic bacteriuria (ABU). 15 years later a reinvestigation was carried out, in women-born 1913-1948. 40 women with ABU and 40 age-matched healthy controls from the population study participated. The frequency of symptomatic urinary tract infections (UTI) had been significantly higher in the ABU group than in the control group during follow-up, but nobody had developed progressive renal disease. Three women in the ABU group and one in the control group had low urine concentrating capacity. All other osmolality values were within normal limits, although there was a significant difference between the two groups. The age-dependent decrease after 15 years was the same in both groups. The number of new hypertensives was the same in both groups. A total of 37.5% were hypertensive in the ABU group and only 12.5% in the control group, but as hypertension had been excluded in the control group at the first investigation the groups could not be compared in this respect.

Monocyte Chemoattractant Protein 1 is a Prognostic Marker in ANCA-Associated Small Vessel Vasculitis

Background. The (anti neutrophil cytoplasmatic autoantibody ANCA), associated small vessel vasculitides (ASVV) are relapsing-remitting inflammatory disorders, involving various organs, such as the kidneys. (Monocyte chemoattractant protein 1 MCP-1) has been shown to be locally up regulated in glomerulonephritis and recent studies have pointed out MCP-1 as a promising marker of renal inflammation. Here we measure urinary cytokine levels in different phases of disease, exploring the possible prognostic value of MCP-1, together with (interleukin 6 IL-6), (interleukin 8 IL-8) and (immunoglobulin M IgM). Methods. MCP-1, IL-6 and IL-8 were measured using commercially available ELISA kits, whereas IgM in the urine was measured by an in-house ELISA. Results. The MCP-1 levels in urine were significantly higher in patients in stable phase of the disease, compared with healthy controls. Patients in stable phase, with subsequent adverse events; had significantly higher MCP-1 values than patients who did not. MCP-1 and IgM both tended to be higher in patients relapsing within three months, an observation, however, not reaching statistical significance. Urinary levels of IL-6 correlated with relapse tendency, and IL-8 was associated with disease outcome. Conclusions. Patients with ASVV have raised cytokine levels in the urine compared to healthy controls, even during remission. Raised MCP-1 levels are associated with poor prognosis and possibly also with relapse tendency. The association with poor prognosis was stronger for U-MCP-1 than for conventional markers of disease like CRP, BVAS, and ANCA, as well as compared to candidate markers like U-IgM and U-IL-8. We thus consider U-MCP-1 to have promising potential as a prognostic marker in ASVV.

Diagnostic and prognostic significance of proteinuria selectivity index in glomerular diseases

The proteinuria selectivity index (SI) describes changes of the glomerular permeability for macromolecules. In the present study, we examine the implications of SI as a diagnostic (199 patients) and a prognostic (49 patients) marker in glomerular diseases. Using SI based on alpha(2)-macroglobulin (alpha(2)-M-SI) or on IgM (IgM-SI) we found that minimal change nephropathy could be discriminated by low SI values and crescentic necrotizing glomerulonephritis by high SI values compared to other diseases. SI based on IgG (IgG-SI) was less useful in determining specific diagnoses. During a follow-up of 46 months creatinine clearance (Cr cl) decreased 36% in a group of patients with high IgG-SI (>0.2) and 38% in a group of patients with high IgM-SI (>1.5(-3)) compared to only 8% in patients with low IgG-SI (</=0.2) or low IgM-SI (</=1.5(-3)). Furthermore, Cr cl decreased more than 30% in 12 (92%) out of thirteen patients with high baseline levels of both IgG-SI and IgM-SI compared to three out of thirteen patients with low baseline values of both the indexes. The decline rate of Cr cl correlated significantly to the SI levels but not to the degree of albuminuria. The findings of the study indicate that urinary excretion of high-molecular-weight proteins, and not of albumin, is a potential prognostic marker in proteinuric glomerulopathies and it may also serve as valuable diagnostic aid in these disorders.

Renal function in proteinuric glomerular diseases correlates to the changes in urine IgM excretion but not to the changes in the degree of albuminuria

UNLABELLED Renal function in proteinuric glomerular diseases correlates to the changes in urine IgM but not to the changes in the degree of albuminuria. BACKGROUND Albuminuria is believed to correlate to the progression of renal failure in glomerular diseases. Nevertheless, many patients with glomerular disorders maintain their renal function despite persistent albuminuria. In previous studies, we found that the baseline urine excretion of IgM, rather than the degree of albuminuria, predicts the renal outcome in glomerulopathies. In the present study, we examine correlations between changes in the content and in the amount of urine proteins and renal survival during a follow-up time of 3.5 years. METHODS An observational study of a mean of 44 (+/- 3.6) months was conducted in 37 proteinuric patients (21 males and 16 females) with biopsy-verified primary glomerular disease. The patients were subdivided, according to the findings at the end of the study, into 3 groups, 1 group with decreasing albuminuria (by more than 50%), 1 group with persisting albuminuria and low (< 0.04 mg/mmol creatinine) urinary IgM excretion and 1 group with persisting albuminuria and with high (> or = 0.04 mg/mmol) urinary IgM excretion. RESULTS All patients that showed remission of albuminuria had also low IgM excretion at the end of the study. All these patients, except 1, maintained their renal function. Patients with persistent albuminuria and high urinary IgM excretion showed a decrease in the glomerular filtration rate (GFR) of a mean of 9.6 ml/min/year compared to a mean GFR increase by 1.5 ml/min/year in patients with low IgM excretion and the same degree of albuminuria (p < 0.01). Seven out of the 9 patients in the former group fall in GFR by more than 5 ml/min/year compared to only 1 of the 10 patients in the latter group. Furthermore, the GFR alterations that occurred during follow-up time correlated in a higher degree to the changes in urinary IgM excretion (r = 0.6, p < 0.01) than to the changes in the degree of albuminuria, (r = 0.4, p < 0.05). A stepwise regression analysis indicated that increased urine IgM excretion is a strong predictor of the GFR decline (r = 0.73, p < 0.001). CONCLUSION High urinary IgM excretion correlates to decreased GFR in primary glomerular diseases regardless of the degree of albuminuria. In parallel, low urinary IgM excretion indicates beneficial prognosis in these diseases. Since IgM passes the glomerular barrier entirely through large shunts or defects in the glomerular capillary wall, decreased urine content of IgM might be considered as a sign of recovery in the glomerular damage.

Long-term effects of reflux nephropathy on blood pressure and renal function in adults.

Aims: We investigated whether the grade of renal damage assessed by urography in adult patients with vesicoureteral reflux can be used to identify patients at risk of developing hypertension and/or deterioration of renal function. In addition, maternal and fetal outcome of pregnancy was studied. Methods: Vesicoureteral reflux was diagnosed at a median age of 27 years (range 16–60) in 115 patients (98 women). Excluding patients subjected to nephrectomy or heminephrectomy after inclusion (n = 12), 88 patients had renal damage at inclusion urography and a median follow-up time of 16 years. The median follow-up time was 18 years in 15 patients without renal damage. Grading of renal damage was performed and blood pressure, serum creatinine concentration and albuminuria were measured. Hypertension was considered to be present if the systolic blood pressure was ≧140 mm Hg and/or the diastolic blood pressure was ≧90 mm Hg. It was classified as mild (<180 mm Hg systolic and <105 mm Hg diastolic), or moderate to severe (≧180 mm Hg systolic and/or ≧105 mm Hg diastolic). Renal function was classified as stable or deteriorating. Results: There was no significant difference in the frequency of hypertension among those with (52%) or without (33%) renal damage, but moderate to severe hypertension (16 patients) was only seen in patients with renal damage. Median systolic and diastolic blood pressure were higher in patients with than in those without renal damage. Malignant hypertension developed in 4 patients, all had extensive renal damage. Deterioration of renal function occurred in 25 patients, 1 with unilateral and 24 with extensive renal damage (bilateral or in a solitary kidney). This was associated with a high frequency of hypertension (92%) and albuminuria (88%). Sixteen patients developed end-stage renal disease. A total of 242 pregnancies occurred in 89 of the 98 women. Preeclampsia occurred in 16 (18%) women. Conclusion: Hypertension in adult patients with reflux nephropathy occurs with any grade of renal damage, whereas deterioration of renal function was strongly associated with extensive bilateral renal damage or damage in a solitary kidney.

Elevated plasma levels of acute phase proteins in mesangioproliferative glomerulonephritis, membranous nephropathy and IgA nephropathy.

In order to study the possible role of active inflammatory processes in clinical indolent primary chronic glomerulonephritides, plasma concentrations of the acute phase proteins: alpha 1-antitrypsin, haptoglobin, orosomucoid and C-reactive protein were measured in 166 glomerulonephritis patients. The patients had a diagnosis of either mesangioproliferative glomerulonephritis, membranous nephropathy or immunoglobulin A nephropathy and were divided in two groups, one with heavy urinary albumin losses and one with moderate to slight urinary albumin excretion. The median plasma concentration values for alpha 1-antitrypsin, haptoglobin and orosomucoid were increased in all three kinds of the investigated glomerulonephritides with exception for orosomucoid in patients with heavy urinary albumin losses and in the membranous nephropathy group. The plasma concentration values for C-reactive protein were not elevated at all in the material. The increase of plasma levels of acute phase proteins could be the result of persistent inflammatory stimuli that occur in primary chronic glomerulonephritides. The finding of unchanging plasma levels of C-reactive protein in contrast to increased concentrations of the other acute phase proteins could be of significance in diagnosing infections or other inflammatory diseases in patients with chronic glomerulonephritis.

The response to antihypertensive therapy is dependent on renal structural changes. A 5-year prospective study of renal biopsy in type 2 diabetic patients with micro-macroalbuminuria

UNLABELLED A substantial fraction of patients with diabetes mellitus develop end-stage renal disease. We wanted to study the influence of renal structural changes on the response to treatment of the systemic blood pressure (BP) in type 2 diabetic patients with micro- or macroalbuminuria. METHODS A 5-year observational prospective study of 40 type 2 diabetic patients. Renal biopsy was performed on the indication micro-macroalbuminuria. Twenty-four-hour ambulatory BP and urine sampling were performed yearly. The goal for treatment was a nightly systolic BP below 140 mmHg. Glomerular filtration rate was examined early with plasma clearance of iohexol. RESULTS The nightly systolic BP goal <140 mmHg was achieved in 23 of 40 patients. The nightly systolic BP at start of study was correlated to the mean level of nightly systolic BP during the observation period. The glomerular basement membrane (GBM) thickness (BMT) was of prognostic significance for achieving the goal for antihypertensive treatment. Of the 12 patients with BMT below the median of 478 nm, 9 (75%) achieved the goal, while only 5 of 12 (42%) with BMT above 478 nm achieved a nightly systolic BP <140 mmHg. Also, the degree of interstitial fibrosis correlated to the nightly systolic BP. CONCLUSION A thick basement membrane and the degree of interstitial fibrosis were associated with a lower number of patients achieving the goal of a nightly systolic BP <140 mmHg.