Efstathios Alexopoulos

COL4A3/COL4A4 Mutations Producing Focal Segmental Glomerulosclerosis and Renal Failure in Thin Basement Membrane Nephropathy

Mutations in the COL4A3/COL4A4 genes of type IV collagen have been found in approximately 40% of cases of thin basement membrane nephropathy, which is characterized by microscopic hematuria and is classically thought to cause proteinuria and chronic renal failure rarely. Here we report our observations of 116 subjects from 13 Cypriot families clinically affected with thin basement membrane nephropathy. These families first came to our attention because they segregated microscopic hematuria, mild proteinuria, and variable degrees of renal impairment, but a dual diagnosis of focal segmental glomerulosclerosis (FSGS) and thin basement membrane nephropathy was made in 20 biopsied cases. Molecular studies identified founder mutations in both COL4A3 and COL4A4 genes in 10 families. None of 82 heterozygous patients had any extrarenal manifestations, supporting the diagnosis of thin basement membrane nephropathy. During follow-up of up to three decades, 31 of these 82 patients (37.8%) developed chronic renal failure and 16 (19.5%) reached end-stage renal disease. Mutations G1334E and G871C were detected in seven and three families, respectively, and were probably introduced by founders. We conclude that these particular COL4A3/COL4A4 mutations either predispose some patients to FSGS and chronic renal failure, or that thin basement membrane nephropathy sometimes coexists with another genetic modifier that is responsible for FSGS and progressive renal failure. The findings presented here do not justify the labelling of thin basement membrane nephropathy as a benign condition with excellent prognosis.

Immune Mechanisms in Idiopathic Membranous Nephropathy: The Role of the Interstitial Infiltrates

Mononuclear inflammatory cells in renal biopsies from 36 patients with membranous nephropathy (MN) were analyzed, using monoclonal antibodies. In the interstitium, monocytes/macrophages and T cells were the predominant cell types (210 +/- 27 and 171 +/- 25/mm2, respectively); in contrast, very few intraglomerular leucocytes, mostly macrophages (1.0 +/- 0.7 cell/glomerular cross-section), were found. Among the interstitial T-cell population, helper/inducer cells (CD4+) predominated (CD4:CD8 ratio, 2.2 +/- 1.5). Natural killer (NK) cells and B lymphocytes were a minor component of the interstitial infiltrates and were almost absent in the glomeruli. Significantly higher numbers of DR-expressing cells were found in the interstitium (322 +/- 20/mm2) than in controls (109 +/- 30), but tubular DR expression was similar to controls (17 +/- 12 mm2). The numbers of total leukocytes and their subsets CD4+, CD8+, monocytes/macrophages, and B cells all correlated with the degree of renal impairment at the time of biopsy, but surprisingly there was no correlation between interstitial cell numbers and the histological severity of tubulointerstitial lesions. Progressive renal impairment over 5 years was associated with many interstitial T cells and monocytes/macrophages in the initial biopsy. Our results suggest that interstitial mononuclear cells may be important determinants in the pathogenesis of MN. Both cellular and humoral immune mechanisms may play a major role in the initiation of the disease, whereas progression toward renal failure seems to be determined mainly by cell-mediated immunity.

Urinary levels of epidermal growth factor, interleukin-6 and monocyte chemoattractant protein-1 may act as predictor markers of renal function outcome in immunoglobulin A nephropathy.

Aim:  Urinary cytokine excretion may reflect histological changes in immunoglobulin A nephropathy (IgAN), and their measurement can give information about disease outcome.

Role of interferon- γ gene polymorphisms in susceptibility to IgA nephropathy: a family-based association study

T helper (h) lymphocytes in pathogenic immune response at mucosal effector site play a key role in IgA nephropathy (IgAN). We evaluated the impact of some Th1/Th2/Th3/TR-type, and of monocyte/macrophage cytokines on IgAN susceptibility with a family-based association study including 53 patients, 45 complete trios, 4 incomplete trios and 36 discordant siblings. Cytokine gene polymorphisms with a potential regulatory role on their production were investigated using the family-based association test (FBAT): IFNγ intron-1 CA repeat at position 1349–1373; IL-13 −1055C/T; TGFβ +915G/C; IL-10 5′-proximal and distal microsatellites; TNFα −308G/A, −238G/A. The FBAT multi-allelic analysis showed an association between IFNγ polymorphism and susceptibility to IgAN (P=0.03). The bi-allelic analysis evidenced that the 13-CA repeat allele was preferentially transmitted to the affected individuals (P=0.006; Bonferroni P-value=0.04). The direct sequencing of IFNγ amplicons showed a strict association between the 13-CA repeat allele and the A variant of the +874T/A single nucleotide polymorphism (SNP rs2430561) directly adjacent to the 5′ end of the microsatellite. The in vitro production of IFNγ evaluated in peripheral blood mononuclear cells from 10 genotyped patients demonstrated a correlation between the +874A allele and a lower production of IFNγ (P=0.028 Mann–Whitney test). This SNP affects IFNγ production lying within a binding site for the transcription factor NF-κB. No significant difference was observed in the 15 years renal survival between IgAN patients carrying different IFNγ gene polymorphisms. This first family-based association study demonstrates that the +874A allele, strictly associated with IFNγ 13-CA repeat allele, confers susceptibility to IgAN, without influencing renal survival.

Drug-Induced Acute Interstitial Nephritis

Acute interstitial nephritis (AIN) is a form of inflammatory renal disease affecting predominantly the tubules and the interstitium. Drugs, particularly beta-lactam antibiotics and non-steroidal anti-inflammatory drugs, are currently the most common causes. The pathogenesis of drug-induced AIN is complex but there is good clinical evidence for an immune-mediated reaction. Clinical findings may be variable depending on the drug involved and the individual response. Most patients recover from the acute renal failure; however, in older patients or in patients with pre-existing renal insufficiency the recovery of renal function may be incomplete.

Treatment of Severe IgA Nephropathy With Omega‐3 Fatty Acids: The Effect of a “Very Low Dose” Regimen

Background. The effect of a “very low dose” of purified omega‐3 fatty acids (PFA) in the progression of severe IgA nephropathy (IgAN) was tested, in a randomized, prospective, controlled trial. Methods. Fourteen patients were assigned to receive a “very low dose” of PFA (0.85 g EPA and 0.57 g PHA) and 14 patients were treated symptomatically and used as controls. Both groups were similar in terms of serum creatinine (Scr) and glomerular filtration rate (GFR) at baseline. Patients were treated for 4 years. The primary end‐points were an increase of 50% or more in Scr or a decrease of 50% or more in GFR at the end of the study. Results. During treatment, 1 patient (7%) in the PFA group and 6 (43%) in the control group had an increase of 50% or more in their Scr (p < 0.01). Also, 1 patient (7%) in the PFA group and 7 (50%) in the control group had a decrease of 50% or more in GFR (p < 0.007). The mean annual change in Scr was 0.2 mg/dL in the PFA group and 1.0 mg/dL in the control group (p < 0.01). The mean annual change in GFR was − 1.4 mL/min in the PFA group and − 3.0 mL/min in the control group (p < 0.001). One patient in the PFA group (7%) and 6 patients in the control group (43%; p < 0.01) developed end‐stage renal disease during the period of observation. Conclusions. A “very low dose” of PFA is also effective in slowing renal progression in high‐risk patients with IgAN and particularly those with advanced renal disease.

Carotid Atherosclerosis and Endothelial Cell Adhesion Molecules as Predictors of Long-Term Outcome in Chronic Hemodialysis Patients

Background/Aims: Cardiovascular disease (CVD) remains the leading cause of increased morbidity and mortality for hemodialysis (HD) patients. The aim of this study was to investigate the predictive values of carotid artery atherosclerotic lesions and endothelial adhesion molecule levels for long-term outcome in non-diabetic HD patients. Methods: 112 HD patients (60 male, mean age 59 years) consecutively entered the study. Atherosclerotic disease was assessed by measuring the mean and maximum intima-media thickness (IMT and IMTmax respectively) of the common carotid arteries using an ultrasound scanner. Circulating intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) levels were measured by ELISA. Patients were followed for the next 5 years and primary end points on follow-up were all-cause death, death from CVD causes and incidence of a CVD event. Results: Kaplan-Meier analysis showed that survival curves for all-cause mortality, CVD mortality and morbidity differed significantly between the upper and lower tertiles of baseline IMT (p = 0.002, p = 0.01 and p = 0.001 respectively) and IMTmax values (p = 0.0007, p = 0.006 and p = 0.0003 respectively), as well as ICAM-1 (p = 0.008, p = 0.003 and p = 0.02 respectively) and VCAM-1 levels (p = 0.004, p = 0.012 and p = 0.025 respectively). In non-adjusted analysis all-cause mortality and CVD mortality and morbidity were significantly associated with IMT (p = 0.003, p = 0.01 and p = 0.001 respectively) and IMTmax values (p = 0.001, p = 0.007 and p = 0.0007 respectively). After adjusting for other significant covariates, IMT values remained associated only with CVD morbidity (p = 0.03), while IMTmax were associated with both CVD mortality and morbidity (p = 0.03 and p = 0.01 respectively). All-cause mortality and CVD mortality and morbidity were also significantly associated with serum ICAM-1 (p = 0.004, p = 0.005 and p = 0.01 respectively) and VCAM-1 levels (p = 0.008, p = 0.02 and p = 0.03 respectively). After adjusting for the same covariates, the associations between ICAM-1 and all-cause mortality and CVD mortality and morbidity remained significant (p = 0.02, p = 0.01 and p = 0.02 respectively), while serum VCAM-1 levels were independently associated only with all-cause mortality (p = 0.02). Conclusions: In non-diabetic HD patients, carotid atherosclerosis and adhesion molecule levels are independent predictors of long-term clinical outcomes and may be useful surrogate markers for risk stratification in these patients.

Acute renal failure in pregnancy

Between 1982 and 1992, 18 cases of pregnancy-related acute renal failure (PR-ARF) were observed (9% of the total number of ARF). Mean age of the women was 32 years (22-40 years). Uterine hemorrhage and preeclampsia/eclampsia were the major causes of ARF, accounting for 61% of the cases. Patchy renal cortical necrosis was suspected in 2 cases whereas signs of disseminated intravascular coagulation (DIC) or microangiopathic hemolytic anemia were present in 6 (33%) and 9 (50%) cases, respectively. Ten women required hemodialysis; and 6 of them, additional plasma exchange sessions. Five patients (28%) died during the acute phase of the illness, mainly due to brain damage, hepatic failure, and sepsis. Among the survivors, a complete (61.5%) or partial recovery (23.1%) was usually seen, but irreversible renal failure was recorded in 2 cases with postpartum hemolytic uremic syndrome (HUS). Short-lasting oligoanuria (< 3 days) represents a good prognostic index. However, the presence of vascular injury (cortical necrosis, HUS) seems to carry a poor prognosis. In conclusion, PR-ARF is still a critical occurrence, associated with serious prognosis for both women and kidneys. So far, the most effective measures remain the careful prevention and the aggressive management of the obstetric complications.

Is Presence of ANCA in Crescentic IgA Nephropathy a Coincidence or Novel Clinical Entity? A Case Series

BACKGROUND There are few anecdotal reports of circulating antineutrophil cytoplasmic autoantibodies (ANCAs) in patients with immunoglobulin A (IgA) nephropathy. STUDY DESIGN Retrospective case series. SETTING & PARTICIPANTS We studied 8 patients with crescentic IgA nephropathy associated with ANCAs against myeloperoxidase (n = 5) and proteinase 3 (n = 3) followed up for 2.4 +/- 1.7 years. They were compared with 26 patients with IgA nephropathy with > 10% crescentic glomeruli, but negative for ANCAs. OUTCOMES We analyzed clinical and histologic features of patients and their response to treatment. MEASUREMENTS Screening for ANCAs was performed using indirect immunofluorescence, and positive results were verified using enzyme-linked immunosorbent assay. RESULTS All patients with crescentic IgA nephropathy and positive for ANCAs, compared with only one-third of ANCA-negative patients, presented with the clinical syndrome of rapid progressive glomerulonephritis. ANCA-positive patients reached a higher peak serum creatinine level within the first 3 months (4.2 +/- 2.2 vs 2.5 +/- 1.9 mg/dL; estimated glomerular filtration rate, 19.3 +/- 10.2 vs 45.9 +/- 30.1 mL/min/1.73 m(2)). ANCA-positive patients with IgA nephropathy had a higher percentage of crescentic glomeruli (54.3% +/- 18%) compared with ANCA-negative patients with crescentic IgA nephropathy (34.5% +/- 26%). ANCA-positive patients were treated using cyclophosphamide and corticosteroids. Kidney function improved in all these patients: serum creatinine level decreased from the peak of 4.2 +/- 2.2 to 1.7 +/- 0.7 mg/dL at the end of follow up (estimated glomerular filtration rate, 19.3 +/- 10.2 to 44.6 +/- 11.1 mL/min/1.73 m(2)). In contrast, no significant improvement was achieved in ANCA-negative patients. CONCLUSION Patients with IgA nephropathy, crescents, and positive for ANCAs represent a clinical entity with a diverse more exaggerated clinical and histologic picture. However, disease in these patients responded well to aggressive immunosuppressive therapy.

Cyclophosphamide Provides No Additional Benefit to Steroid Therapy in the Treatment of Idiopathic Membranous Nephropathy

Thirty-six patients with idiopathic membranous nephropathy were retrospectively studied. The mean age was 47 years and the male to female ratio 25 to 11. Twenty-eight patients (77.8%) had nephrotic syndrome at first investigation. Nineteen patients received corticosteroids alone (group A) and 17 received corticosteroids combined with cyclophosphamide (group B). The mean period of follow-up was 58.9 months (range, 12 to 156 months). The two groups did not differ in clinical or laboratory features at the time of biopsy or at the start of treatment. In the entire series a complete remission of proteinuria occurred in 13 of 36 patients (36.1%) and a partial remission occurred in 13 (36.1%); 10 patients (27.8%) had no response. Optimal remission of proteinuria was usually recorded 6 to 12 months after the start of treatment. The two groups showed no statistical differences regarding the rate of complete (seven v six patients; P = not significant) or partial (six v seven patients; P = not significant) remissions. Two patients (one from each group) entered end stage renal failure during follow-up. At last assessment, the number of patients with complete remission (four v three patients; P = not significant), nonnephrotic proteinuria (nine v nine patients; P = not significant), or nephrotic syndrome (five v four patients; P = not significant) was similar in both groups. In addition, final plasma creatinine did not differ significantly between the two groups (1.8 ± 2.3 mg/dL v 2.6 ± 2.6 mg/dL; P = not significant). In conclusion, both treatment regimens were found to be equally effective in decreasing proteinuria and preserving renal function in adult idiopathic membranous nephropathy. Cyclophosphamide appeared not to offer any definite advantage over corticosteroids alone in the treatment of the disease.