Features of the course and diagnosis of lupus podocytopathy
One of the reasons for the development of nephrotic syndrome (NS) in patients with systemic lupus erythematosus (SLE) is lupus podocytopathy (LP), a rare variant of kidney damage in SLE that accounts for only 0.6-1.5% of cases. The diagnosis of lupus podocytopathy in clinical practice remains difficult. Despite the accumulated information about this form of kidney damage in SLE, the lack of generally accepted diagnostic criteria and low awareness of practicing physicians, both rheumatologists and nephrologists, leads to errors in the management of patients with this complication. The clinical observation presented demonstrates this problem: unrecognized LP caused the withdrawal of the diagnosis of SLE, which led to the abolition of maintenance therapy, followed by the development of a relapse of the disease. At the same time, the described patient had almost all the most characteristic clinical features of LP, manifested the disease with a full-blown nephrotic syndrome, although SLE debuted earlier with the articular syndrome and constitutional symptoms of mild severity, as well as damage to the thyroid gland by the type of autoimmune thyroiditis, and therefore the diagnosis was not established on time. Subsequently, at the first recurrence of the disease, the patient demonstrated a vivid SLE clinic with skin lesions in the form of «butterfly-type» erythema, hematological manifestations represented by cytopenic syndrome, constitutional symptoms, as well as immunological disorders in the form of detection of ANF, a high titer of antibodies to double-stranded DNA, antibodies to several other extractable nuclear antigens. The morphological feature of LP in our patient was a picture of MCD without signs of mesangial LN of class I or II. The presence of podocytopathy in combination with the clinical and immunological manifestations of SLE at the onset of the disease, the appearance of new characteristic signs of lupus in the future, and the obvious relationship between relapses of NS and exacerbations of the disease, made it possible not only to return the previously rejected diagnosis of SLE but also to classify kidney damage as lupus podocytopathy. In connection with relapses of NS, tacrolimus was prescribed.