374 Ana negative renal limited lupus nephritis –a rare entity

Background and aimsAntinuclear antibodies (ANA) in serum is considered a decisive diagnostic test for SLE. ANA negative SLE is a subgroup of SLE that is infrequently recognised. We report an unusual case of seronegative SLE which presented as rapidly progressive renal failure with no other systemic manifestations.Methods34 year old female presented with fever, nephrotic range proteinuria and rapidly progressive renal failure. She did not have any other systemic features of SLE. Her clinical, biochemical and serological findings are as shown in table 1. She had low complementemia, but her ANA, ANA profile including anti double stranded DNA (anti- dsDNA) antibodies and anti cardiolipin antibody was negative.Renal biopsy on light microscopy showed diffuse proliferative glomerulonephritis with a full house on immunofluorescence including C1q consistent with class 4 lupus nephritis (Figure 1). A diagnosis of ANA negative renal limited lupus nephritis was made.Abstract 374 Table 1Abstract 374 Figure 1ResultsShe was treated with pulse methyl prednisolone followed by oral steroids1mg/kg/day and pulse cyclophosphamide 500–750 mg/m2 body surface area as per NIH protocol. She recovered completely and is on follow-up for two years. She has remained persistently negative for all ANA antibodies including anti-dsDNA antibodies.ConclusionsOurs is an unusual case of ANA negative renal limited lupus nephritis. The low complement levels, full house nephropathy in immunofluorescence and response to therapy were important clues in diagnosing the case. We report this patient to highlight the possibility of SLE in seronegative patients as well in order to avoid delay in the management.