Age and gender-related incidence of chronic renal failure in a French urban area: a prospective epidemiologic study

OBJECTIVE.: To determine the age- and gender-related incidence of chronicrenal failure in a French urban area. METHODS.: Prospective study of adult patients newly identified as havingestablished, chronic renal failure defined by serum creatinine(Scr) 200 µmol/l, with the cooperation of all nephrologyand dialysis units in the Ile de France district (10,660,000inhabitants) during a 1-year period. RESULTS.: 2775 patients (1780 males, 995 females) were referred with Scr200 µmol/l between July 1991 and June 1992, an overallincidence of 260/million population. 847 had advanced renalfailure (Scr 500 µmol/l) and 541 patients (19.5%) were75 years of age. The age-related incidence was 92, 264, 523and 619/million population in the age groups 20–39, 40–59,60–74 and 75 years old, respectively. The annual incidencewas twice as high in males than in females up to 75 years andthree times as high in patients 75 years (1124 vs 356/millionpopulation). Based on the proportion of patients reaching end-stagerenal failure within one year of referral, the minimal estimationof the need for supportive therapy is 81/million/year. CONCLUSIONS.: This epidemiological study in a large French urban area indicatesan incidence of 260 patients per million population annuallyreferred to nephrology units for chronic renal failure definedby Scr 200 µmol/l, with a marked preponderance of malesand a dramatic increase of incidence with age in both genders.     

Antiphospholipid antibodies in a series of 25 cases of lupus without antinuclear antibodies. Comparison with a series of 91 lupus patients with antinuclear antibodies

Twenty-five patients with at least 3 of 1982 ARA criteria of SLE but without the ANA, were compared with 91 patients with 4 or more of the ARA criteria of lupus with positive ANA. The ANA-negative group was characterised by the low incidence of skin involvement, serous effusions and alopecia, and a relatively high incidence of thrombocytopaenia and venous and arterial thrombosis. Three types of antiphospholipid antibodies were looked for: the VDRL, antiprothrombinase and anticardiolipin antibodies by an immuno-enzymatic method. The VDRL was the only antibody which was significantly commoner in the ANA-negative group. Statistical studies showed that the three methods of demonstrating antiphospholipid antibodies detected crossed but not identical specificities. In the ANA-positive group only the antiprothrombinase was associated with a high incidence of venous thrombosis and stroke. In the ANA-negative group, only the anticardiolipin antibodies were associated with a high incidence of arterial or venous thrombosis. Two subgroups may be identified in the group of ANA-negative lupus patients: firstly, those with high anticardiolipin antibody titres with a high incidence of thrombotic and haematological complications, and, secondly, patients with low anticardiolipin antibody levels with a high incidence of cutaneous involvement, serous effusions and Raynaud's phenomenon.     

HLA-A1, B8-phenotype association and HBs antigenemia evolution in 440 hemodialyzed patients.

HBs antigen (HBsAg) has been followed up every month in 440 hemodialyzed patients, typed for 26 HLA alleles of the A and B loci. An abnormally high rate of the HL-A-A1, B8 association (18.6%) was found in the group of patients able to eliminate HBsAg, when compared with the normal French population (5.05%, p less than 10(-4), and with the group of patients unable to eliminate HBsAg (7.0%, less than 0.01). Chronic aggressive hepatitis was only found in the latter. This high frequency of the HLA-A1, B8 association has also been found in patients with seronegative active chronic hepatitis and suggests that this phenotype might be associated with high immune response against HBsAg.     

Clinical value of crystalluria study

Crystalluria is a marker of urine supersaturation present in both normal and pathological conditions. Indeed, nature and characteristics of the spontaneous crystalluria are of clinical interest for detecting and following biological disorders involved in renal diseases. Method. Crystalluria examination should preferably be performed on first morning urine or fresh fasting voiding samples by polarised microscopy in a Malassez cell. Urine samples must be stored at 37 degrees C or at room temperature and examined within two hours following voiding. Results and discussion. Crystalluria should be interpreted according to various criteria: 1) chemical nature of crystals for abnormal crystals such as struvite, ammonium urate, cystine, dihydroxyadenine, xanthine or drugs; 2) crystalline phase of common chemical species as calcium oxalates, calcium phosphates and uric acids; 3) crystal morphology (calcium oxalates); 4) crystal size (calcium oxalates); 5) crystal abundance (calcium oxalates, calcium phosphates, uric acids, cystine); 6) crystal aggregation (calcium oxalates); 7) frequency of crystalluria assessed on serial first morning urine samples, a very useful tool for long-term surveillance of patients. Within calcium oxalate crystalluria, presence of whewellite is a marker of elevated oxalate concentration (urine oxalate > 0.3 mmol/L); a crystal number > 200/mm 3 is highly suggestive of heavy hyperoxaluria of genetic or absorptive origin. Predominant weddellite crystalluria is most often indicative of an excessive urine calcium concentration (> 3.8 mmol/L); a dodecahedric aspect of the crystals is a marker for heavy hypercalciuria (> 6 mmol/L) while an increased crystal size (>or= 35 microm) is indicative of simultaneous hypercalciuria and hyperoxaluria. Calculation of the global crystal volume, especially when applied to calcium oxalates or cystine, is a clinically useful tool for the monitoring of patients suffering from primary hyperoxaluria or cystinuria. Lastly, presence of crystalluria in more than 50% of serial first voided morning urine samples is in our experience the most reliable biological marker for detecting the risk of stone recurrence in lithiasic patients. Conclusion. Crystalluria examination is an essential laboratory test for detecting and following pathological conditions, which may induce renal stone disease or alter kidney function due to urine crystals.     

Early prediction of IgA nephropathy progression: proteinuria and AOPP are strong prognostic markers

BACKGROUND: Inflammation and oxidative stress have been incriminated in the pathogenesis of IgA nephropathy (IgAN). The aim of the present study was to assess whether markers reflecting these pathophysiologic processes, namely C-reactive protein (CRP) and advanced oxidation protein products (AOPP), would allow-in conjunction with clinical and histopathologic parameters-to predict disease progression. METHODS: Between 1994 and 1997, 120 adult patients with biopsy-proven IgAN were included in a prospective cohort study, and followed until the end of 2002 or start of dialysis. In every patient, we determined plasma levels of CRP and AOPP. These parameters were included, together with clinical data, in a multivariate Cox proportional hazard regression analysis, with halving of baseline creatinine clearance as the primary renal end point. RESULTS: A total of 51 patients reached the renal end point, including 30 who had to start dialysis. With multivariate analysis, the most potent independent risk factors of poor renal outcome were proteinuria > or =1 g/day [proportional hazard risk (HR) = 23.7, P= 0.0001], hypertension (HR = 8.13, P= 0.008), and AOPP plasma level (HR = 1.09 per 10 micromol/L, P= 0.042), whereas angiotensin II inhibitors were protective (HR = 0.19, P= 0.001). CONCLUSION: Our data support the role of oxidative stress in the pathogenesis of IgAN and suggest that patients with proteinuria > or =1 g/day should be eligible for early implemented antioxidant and/or anti-inflammatory therapeutic strategies, with AOPP plasma level as a surrogate marker to evaluate their effects.     

Octogenarians reaching end-stage renal disease: cohort study of decision-making and clinical outcomes

The fate of octogenarians reaching end-stage renal disease (ESRD) is poorly defined, and implicit dialysis rationing may be practiced in this age group. The main objectives of this study were to analyze the characteristics of pre-ESRD octogenarians offered dialysis or not and to identify factors influencing mortality while on dialysis, to improve prognosis assessment and decision-making. In this single-center cohort, 146 consecutive pre-ESRD octogenarians were referred to a nephrology unit over a 12-yr period (1989 to 2000). Main outcome measures were baseline characteristics of patients offered dialysis and conservative therapy and overall and 1-yr survival according to effective treatment. A therapeutic decision was made for 144 patients. Octogenarians who were not proposed dialysis (n = 37) differed from those who were proposed dialysis (n = 107) mainly in terms of social isolation (43.3% versus 14.7%; P = 0.03), late nephrologic referral (51.4% versus 28.9%; P = 0.01), Karnofsky score (55 +/- 18 versus 63 +/- 20; P = 0.03), and diabetic status (22.2% versus 6.5%, P = 0.008). Six patients refused the dialysis proposal. During the 12-yr observation period, 99 patients died (68.7%). Median survival was 28.9 mo (95% CI, 24 to 38) in patients undergoing dialysis, compared with 8.9 mo (95% CI, 4 to 10) in patients treated conservatively (P < 0.0001). In multivariable piecewise Cox analysis, independent predictors of death within 1 yr on dialysis were poor nutritional status, late referral, and functional dependence. Included in a survivor function, these covariates predict groups with low and high 1-yr mortality risk. Beyond 1 yr on dialysis, the only independent predictor of death was the presence of peripheral vascular disease. It is concluded that beside a patient's individual refusal, late referral, social isolation, low functional capacity, and diabetes may have oriented medical decision toward withholding dialysis in a significant proportion of pre-ESRD octogenarians. Although most patients on dialysis experienced a substantial prolongation of life, identification of mortality predictors in this age group should improve the process of decision-making regarding the expected benefit of renal replacement therapy.     

Pregnancy in IgA nephropathy, reflux nephropathy, and focal glomerular sclerosis

Fetal outcome was retrospectively studied in 217 pregnancies observed during the past two decades in 93 patients, 34 suffering from IgA nephropathy (IgAGN, 69 pregnancies), 53 from reflux nephropathy (RN, 137 pregnancies), and six from focal glomerular sclerosis (FGS, 10 pregnancies). Overall incidence of live births was 175 in 217 (81%). Fetal loss, corrected for induced abortions, was 10 in 66 (15%) in IgAGN, 18 in 129 (14%) in RN, and 2 in 10 in FGS. Renal failure and hypertension preexisting prior to conception or developing early in pregnancy were the most important factors associated with unsuccessful fetal outcome whereas urinary tract infection had limited effects in RN patients. Influence of pregnancy on the course of maternal renal disease was evaluated in the same groups of patients. An abnormally rapid deterioration of renal function was observed in three of the women with IgAGN and in one of the RN patients (with an additional case among 46 further female RN patients) but in none in the FGS group. All five women experiencing functional deterioration had a serum creatinine (SCr) level of greater than or equal to 200 mumol/L (2.3 mg/dL) and hypertension at conception. Hypertension in pregnancy was highly predictive of recurrence of hypertension in subsequent pregnancy and of the remote development of permanent hypertension in IgAGN patients. We conclude that when renal function is preserved, pregnancy is usually successful and no deleterious effects on maternal renal disease are to be expected in patients with IgAN, RN, and probably FGS.(ABSTRACT TRUNCATED AT 250 WORDS)