SLE in a Multiethnic US Cohort (LUMINA) XL II: Factors of Proteinuria
SLE in a Multiethnic US Cohort (LUMINA) XL II: Factors of Proteinuria
Objectives: To determine the factors predictive of new or worsening proteinuria in a large multiethnic cohort of patients with systemic lupus erythematosus (SLE).
Methods: Five hundred and twenty-nine SLE patients from a multiethnic US cohort [LUpus in MInorities: NAture versus Nurture (LUMINA)] were evaluated for new or worsening proteinuria using the categories of the Systemic Lupus Activity Measure-Revised: (1), normal; (2), trace or 1+ proteinuria on the dipstick; (3), 2-3+ proteinuria and (4), ≥4+ proteinuria. A rise in urinary protein was considered a positive event visit. Basic demographic and socioeconomic variables were assessed at baseline (T0). Clinical and immunological variables including disease features, activity, duration, comorbidities (such as hypertension and diabetes), medications and autoantibodies were assessed at the visit preceding a positive event visit. Selected HLA-DR and HLA-DQ alleles, and FCGR receptor polymorphisms were assessed. Data were analysed using logistic regression analyses and generalized estimating equations.
Results: There were 243 patients (59.1% of 93 Texan Hispanics, 37.0% of 100 Puerto Rican Hispanics, 58.0% of 181 African Americans and 29.7% of 155 Caucasians) with new or worsening proteinuria, and 364 positive events in 2801 visits. Younger age [Odds ratio (OR) = 1.013, 95% confidence limits (CL) = 1.001-1.024, P < 0.0334], anti-dsDNA (OR = 1.554, CL = 1.149-2.100, P < 0.0042), and HLA-DRB1*1503 (OR = 1.746, 95% CL = 1.573-2.2673, P < 0.0103) were found to independently predict the occurrence of new or worsening proteinuria.
Conclusion: The factors predictive of new or worsening proteinuria include traditional factors associated with lupus nephritis, such as age and anti-dsDNA, as well as HLA-DRB1*1503, which has not been previously described in association with lupus nephritis, new or worsening proteinuria.
Lupus nephritis remains a major cause of morbidity among patients with systemic lupus erythematosus (SLE). Sociodemographic, clinical, immunological and genetic features have been associated with the occurrence of lupus nephritis. We have previously reported that patients of African American or Hispanic ethnicity (predominantly of Mexican ancestry), those who are not married/living together, with greater disease activity (excluding the renal items) and those who exhibit anti-dsDNA or anti-RNP antibodies are more likely to develop lupus nephritis after being diagnosed with SLE. Several investigators have examined the factors associated with declining renal function in lupus nephritis, defined as a rise in proteinuria and/or serum creatinine levels. These studies focused primarily on the factors associated with the occurrence of end-stage renal disease (ESRD), the response, safety and efficacy of different therapies, as well as the potential for a drug-induced remission. Not surprisingly, early and aggressive treatment of lupus nephritis can lead to improved outcomes. Thus, identification of the factors associated with the occurrence of new or worsening proteinuria, an event which usually precedes a rise in serum creatinine levels, seems to be inherently advantageous.
We have sought to identify the sociodemographic, clinical, immunological and genetic factors associated with new or worsening proteinuria utilizing the longitudinal data from LUMINA (LUpus in MInorities: NAture versus Nurture), a multiethnic cohort of SLE patients.
Abstract and Introduction
Abstract
Objectives: To determine the factors predictive of new or worsening proteinuria in a large multiethnic cohort of patients with systemic lupus erythematosus (SLE).
Methods: Five hundred and twenty-nine SLE patients from a multiethnic US cohort [LUpus in MInorities: NAture versus Nurture (LUMINA)] were evaluated for new or worsening proteinuria using the categories of the Systemic Lupus Activity Measure-Revised: (1), normal; (2), trace or 1+ proteinuria on the dipstick; (3), 2-3+ proteinuria and (4), ≥4+ proteinuria. A rise in urinary protein was considered a positive event visit. Basic demographic and socioeconomic variables were assessed at baseline (T0). Clinical and immunological variables including disease features, activity, duration, comorbidities (such as hypertension and diabetes), medications and autoantibodies were assessed at the visit preceding a positive event visit. Selected HLA-DR and HLA-DQ alleles, and FCGR receptor polymorphisms were assessed. Data were analysed using logistic regression analyses and generalized estimating equations.
Results: There were 243 patients (59.1% of 93 Texan Hispanics, 37.0% of 100 Puerto Rican Hispanics, 58.0% of 181 African Americans and 29.7% of 155 Caucasians) with new or worsening proteinuria, and 364 positive events in 2801 visits. Younger age [Odds ratio (OR) = 1.013, 95% confidence limits (CL) = 1.001-1.024, P < 0.0334], anti-dsDNA (OR = 1.554, CL = 1.149-2.100, P < 0.0042), and HLA-DRB1*1503 (OR = 1.746, 95% CL = 1.573-2.2673, P < 0.0103) were found to independently predict the occurrence of new or worsening proteinuria.
Conclusion: The factors predictive of new or worsening proteinuria include traditional factors associated with lupus nephritis, such as age and anti-dsDNA, as well as HLA-DRB1*1503, which has not been previously described in association with lupus nephritis, new or worsening proteinuria.
Introduction
Lupus nephritis remains a major cause of morbidity among patients with systemic lupus erythematosus (SLE). Sociodemographic, clinical, immunological and genetic features have been associated with the occurrence of lupus nephritis. We have previously reported that patients of African American or Hispanic ethnicity (predominantly of Mexican ancestry), those who are not married/living together, with greater disease activity (excluding the renal items) and those who exhibit anti-dsDNA or anti-RNP antibodies are more likely to develop lupus nephritis after being diagnosed with SLE. Several investigators have examined the factors associated with declining renal function in lupus nephritis, defined as a rise in proteinuria and/or serum creatinine levels. These studies focused primarily on the factors associated with the occurrence of end-stage renal disease (ESRD), the response, safety and efficacy of different therapies, as well as the potential for a drug-induced remission. Not surprisingly, early and aggressive treatment of lupus nephritis can lead to improved outcomes. Thus, identification of the factors associated with the occurrence of new or worsening proteinuria, an event which usually precedes a rise in serum creatinine levels, seems to be inherently advantageous.
We have sought to identify the sociodemographic, clinical, immunological and genetic factors associated with new or worsening proteinuria utilizing the longitudinal data from LUMINA (LUpus in MInorities: NAture versus Nurture), a multiethnic cohort of SLE patients.
