Delayed seropositive lupus nephritis: a clinical dilemma.

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder with a prevalence estimated at 43.7 per 100 000 individuals globally and a higher incidence among women (78.73 per 100 000) versus men (9.31 per 100 000). Laboratory tests such as antinuclear antibody and antidouble-stranded DNA (anti-dsDNA), using the Crithidia luciliae assay, exhibit high sensitivity (98%) and specificity (99%) in detecting SLE, respectively. Approximately half of patients with SLE develop lupus nephritis, which is associated with significant morbidity and a mortality rate of 5%-25% due to progression to kidney failure. The histological classification of lupus nephritis, particularly classes IV and V, is pivotal in its diagnosis and management. This case report describes a young woman in her 20s with lupus nephritis characterised by delayed seropositivity and no other clinical manifestations. It also underscores the importance of follow-up care to manage medication side effects and prevent disease sequelae, such as thromboses.