The value of electron microscopy in the diagnosis and clinical management of lupus nephritis

The diagnosis and clinical management of patients with lupus nephritis can be a challenge from a clinicopathologic point of view. Although the majorit y of patients that are biopsied already have either an established clinical diagnosis or a presumptive diagnosis of systemic lupus erythematosus, dete rmination of the immunomorphologic characteristics, pattern, and distributi on of renal involvement is important for clinical management. In a clear su bset of these patients with lupus nephritis, electron microscopy plays a pi votal role in accurately characterizing the type of renal involvement and d etermining the degree of activity, providing useful and objective guides fo r patients' management. Ultrastructural evaluation can also be crucial in t he initial diagnosis of patients with lupus who, at the time of biopsy, lac k either diagnostic clinical manifestations and/or serologic markers, and a re therefore clinically unsuspected. Electron microscopic evaluation also p lays a significant role in the evaluation of renal dysfunction in transplan t patients with lupus nephritis, helping to determine whether recurrence of the lupus has occurred in the renal allograft. There are some ultrastructu ral findings that, although not pathognomonic, in the proper clinico-pathol ogic context are very suggestive or even diagnostic of lupus nephritis. Cor relating light, immunofluorescence, and electron microscopic findings withi n the clinical context of lupus nephritis cases is crucial for appropriate clinical management. In some of these patients, electron microscopy provide s key information that cannot be otherwise obtained.