Proliferative lupus nephritis in the absence of overt systemic lupus erythematosus: A historical study of 12 adult patients

Nonlupus Full House Nephropathy: A Systematic Review

Key Points

Nonlupus full house nephropathy is a rare, complex entity: confusion arises by the low-quality evidence and the lack of consensus on nomenclature. This systematic review supports that systemic lupus erythematosus and nonlupus full house nephropathy are distinct clinical entities, with comparable outcomes. The identification of three pathogenetic categories provides further clues for a shared clinical and diagnostic approach to the disease.

Background

The presence of a full house pattern at immunofluorescence on kidney biopsy in a patient without clinical and laboratory features of systemic lupus erythematosus (SLE) has led to the descriptive term nonlupus full house nephropathy. This systematic review and meta-analysis focus on nonlupus full house nephropathy nomenclature, clinical findings, and outcomes.

Methods

In a reiterative process, all identified terms for nonlupus full house nephropathy and other medical subject headings terms were searched in PubMed. Out of 344 results, 57 records published between 1982 and 2022 were included in the analysis. Clinical data of single patients from different reports were collected. Patients were classified into three pathogenetic categories, which were compared according to baseline characteristics, treatments, and outcomes.

Results

Out of the 57 records, 61% were case reports. Nonlupus full house nephropathy was addressed with 17 different names. We identified 148 patients: 75 (51%) were men; median age 35 (23–58) years. Serum creatinine and proteinuria at onset were 1.4 (0.8–2.5) mg/dl and 5.7 (2.7–8.8) g/d. About half of patients achieved complete response. A causative agent was identified in 51 patients (44%), mainly infectious (41%). Secondary nonlupus full house nephropathy was mostly nonrelapsing with worse kidney function at onset compared with idiopathic disease (P = 0.001). Among the 57 patients (50%) with idiopathic nonlupus full house nephropathy, complete response was comparable between patients treated with immunosuppression and supportive therapy; however, proteinuria and creatinine at onset were higher in patients treated with immunosuppression (P = 0.09 and P = 0.07). The remaining 7 patients (6%) developed SLE after a median follow-up of 5.0 (1.9–9.0) years.

Conclusions

Our data support that SLE and nonlupus full house nephropathy are distinct clinical entities, with comparable outcomes. A small subset of patients develops SLE during follow-up. Nonlupus full house nephropathy is addressed by many different names in the literature. The identification of three pathogenetic categories provides further clues for the management of the disease.

Seronegative Full-house Nephropathy with Crohn's Disease

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease. Lupus nephritis (LN) is a major risk factor for mortality in SLE, and glomerular "full-house" immunofluorescence staining is a well-known characteristic of LN. However, some cases of non-lupus glomerulonephritis can also present with a "full-house" immunofluorescence pattern. We recently encountered a patient with full-house nephropathy (FHN) during adalimumab administration for Crohn's disease. IgA nephropathy or idiopathic FHN was diagnosed, and treatment with steroids was started, after which there was improvement in proteinuria. The prognosis of FHN has been reported to be poor; therefore, aggressive treatment is required for such patients.

Sensitivity and Specificity of Pathologic Findings to Diagnose Lupus Nephritis

BACKGROUND AND OBJECTIVES

In 2012, the Systemic Lupus International Collaborating Clinics proposed that lupus nephritis, in the presence of positive ANA or anti-dsDNA antibody, is sufficient to diagnose SLE. However, this "stand-alone" kidney biopsy criterion is problematic because the ISN/RPS classification does not specifically define lupus nephritis. We investigated the combination of pathologic features with optimal sensitivity and specificity for the diagnosis of lupus nephritis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Three hundred consecutive biopsies with lupus nephritis and 560 contemporaneous biopsies with nonlupus glomerulopathies were compared. Lupus nephritis was diagnosed if there was a clinical diagnosis of SLE and kidney biopsy revealed findings compatible with lupus nephritis. The control group consisted of consecutives biopsies showing diverse glomerulopathies from patients without SLE, including IgA nephropathy, membranous glomerulopathy, pauci-immune glomerulonephritis, membranoproliferative glomerulonephritis (excluding C3 GN), and infection-related glomerulonephritis. Sensitivity and specificity of individual pathologic features and combinations of features were computed.

RESULTS

Five characteristic features of lupus nephritis were identified: "full-house" staining by immunofluorescence, intense C1q staining, extraglomerular deposits, combined subendothelial and subepithelial deposits, and endothelial tubuloreticular inclusions, each with sensitivity ranging from 0.68 to 0.80 and specificity from 0.8 to 0.96. The presence of at least two, three, or four of the five criteria had a sensitivity of 0.92, 0.8, and 0.66 for the diagnosis of lupus nephritis, and a specificity of 0.89, 0.95, and 0.98.

CONCLUSIONS

In conclusion, combinations of pathologic features can distinguish lupus nephritis from nonlupus glomerulopathies with high specificity and varying sensitivity. Even with stringent criteria, however, rare examples of nonlupus glomerulopathies may exhibit characteristic features of lupus nephritis.