Abstracts

Coppo R, D'Amico G. Factors predicting progression of IgA nephropathies. J Nephrol. 2005 Sep-Oct;18(5):503-12.

Nephrology, Dialysis and Transplantation, Regina Margherita Hospital, Turin--Italy. nefrologia@oirmsantanna.piemonte.it

The difficulties in defining the natural history of primary IgA nephropathy (IgAN) depend upon the pre-selection of patients for renal biopsy, a true individual variability - ranging from asymptomatic to rapidly progressive forms - as well as the use of different classifications of the renal lesions and statistical analyses sometimes carrying incorrect modalities. Long-term natural history studies have demonstrated that the rate of progression has an extremely wide range, from 5 to 25% after 10 years and 25-50% at 20 years, and complete remission is reported as well in 5 to 30% of cases. A geographic variability has been confirmed in a tri-continental study, explainable only partly by the earlier referral. Among the factors predicting progression, the more frequent in cohorts showing worse actuarial survival at 10 years are those associated with the advanced phases of renal damage, as increased creatinine level, arterial hypertension and nephrotic range proteinuria. A multivariate statistical approach showed the relevance of proteinuria during follow-up (percent duration of massive proteinuria or proteinuria at 1 year) more than proteinuria at the onset. Mean blood pressure value (MAP) and proteinuria during follow-up were independent predictors of end-stage CKD. Note the predictive value of severe microscopic hematuria in several studies. As far as histological features are concerned, strong independent predictors of progression at Cox multivariate analysis are the severity of glomerular sclerosis and interstitial fibrosis. The presence of crescents was a risk factor in almost all studies at univariate analysis, but did not maintain a significant predictor value at multivariate analysis. Conversely the association between crescents and tuft adhesions, possibly resulting from previous segmental necrosis, was found to be a significant risk factor. The extent of mesangial proliferation and parietal expansion of deposits was not significantly associated to unfavourable prognosis at multivariate analysis. The analysis of risk factors for progression of IgAN related to Henoch-Schoenlein purpura (HSP) failed to demonstrate any prognostic value for the presence and severity of extra-renal signs of vasculitis or presence of triggering factors. At multivariate Cox analysis, age and mean proteinuria during follow-up were powerful independent prognostic predictors. Proteinuria at baseline was not significantly related to renal progression, nor were hypertension or impaired renal function at onset. It is of interest that data at onset and at renal biopsy (renal function impairment, hypertension, nephrotic-range proteinuira) were not significantly related with renal detrimental progression. Neither had prognostic value the finding of crescents involving up to 75% of glomeruli.

Davin JC, Ten Berge IJ, Weening JJ. What is the difference between IgA nephropathy and Henoch-Schonlein purpura nephritis? Kidney Int. 2001 Mar;59(3):823-34.

Department of Pediatrics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. j.c.davin@amc.uva.nl

Henoch-Schonlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) are considered to be related diseases since both can be encountered consecutively in the same patient, they have been described in twins, and bear identical pathological and biological abnormalities. Apart from the presence of extrarenal clinical signs found only in HSPN, other differences are noticed between the two diseases. The peak age ranges between 15 and 30 years for a diagnosis of IgAN, whereas HSPN is mainly seen in childhood. Nephritic and/or nephrotic syndromes are more often seen at presentation in HSPN. In contrast to IgAN, HSPN has been described in association with hypersensitivity. Endocapillary and extracapillary inflammations as well as fibrin deposits in the glomerulus are more frequent in HSPN. No major biological differences have been found between the two illnesses, except for a larger size of circulating IgA-containing complexes (IgA-CC) and a greater incidence of increased plasma IgE levels in HSPN. As tissue infiltration by leukocytes is a major feature of HSPN vasculitis, a possible role of a more potent activation of the latter cells by IgA-CC and/or circulating chemokines in HSPN should be considered. Further studies are required to elucidate this possible mechanism as well as the role of hypersensitivity in HSPN.

Kawasaki, Y., J. Suzuki, et al. (2003). "Clinical and pathological features of children with Henoch-Schoenlein purpura nephritis: risk factors associated with poor prognosis." Clin Nephrol 60(3): 153-60.

OBJECTIVE: To clarify the risk factors related to prognosis in patients with Henoch-Schoenlein purpura nephritis (HSPN), we investigated the cases with HSPN on long-term observation.

METHODS: We enrolled 114 patients who had been diagnosed with HSPN from 1974-1997. These patients were divided into 2 groups based upon features at last follow-up. One group, designated "favorable", consisted of 69 patients with normal urine and 25 patients with minor urinary abnormalities, and the second group, designated "unfavorable", consisted of 15 patients with active renal disease and 5 patients with renal failure. The clinical features, laboratory data and pathological findings were investigated in 2 groups.

RESULTS: Nephrotic syndrome, decreased factor XIII activity, hypertension and renal failure at onset were more frequent in "unfavorable" than in "favorable". The rate of glomeruli with crescents, macrophage infiltrations, tubulointerstitial changes and acute exacerbation in "unfavor!
able" were higher than those in "favorable". There were 5 cases with renal insufficiency, and renal survival rate was 95.6% for over 15 years.

CONCLUSIONS: These results suggest that the above mentioned risk factors play an important role in prognosis of the patients with active renal disease and renal failure.

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