Clinicomorphological features of nephropathy in primary and secondary antiphospholipid syndrome

AIM: To investigate specific features of extrarenal manifestations of antiphospholipid syndrome (APS) in patients with APS-associated nephropathy (APSN) in primary APS and lupus nephritis (LN) with secondary APS; to compare clinicomorphological signs of APSN in primary and secondary APS. MATERIAL AND METHODS: We examined 44 APSN patients with primary APS and 90 patients with LN: 57 with secondary APS, 33 with antiphospholipid antibodies (APA) without history of thrombosis. In addition to clinical and immunological examination, detection of serological APS markers, morphological examination of renal tissue and ultrasound dopplerography (USDG) of the renal vessels were made (in some patients) for assessment of the condition of intrarenal vascular bed. RESULTS: In patients with primary APS, renal disorder and secondary APS in LN frequency of arterial thrombosis doubles that of venous ones. Renal disorder irrespective of a clinical APS form (primary, secondary) combines with affection of the CNS, heart and skin (livedo). This correlates with frequency of arterial thrombosis. In patients with primary APSN rate of arterial hypertension (AH), especially severe, and renal dysfunction is higher than in LN with APS while this group is characterized by more severe proteinuria, microhematuria and higher incidence of nephrotic syndrome. A direct correlation exists between the incidence of arterial thrombosis and severity of AH, between AH and renal ischemia by USDG. Morphologically, glomerulosclerosis, marked arteriolosclerosis and diffuse interstitial sclerosis occur more often in patients with primary APSN compared to LN patients with APS. CONCLUSION: In primary and secondary (in SLE) APS combination of APSN with impairment of the CNS, heart and skin, correlation of its basic clinical manifestations with arterial thrombosis allow us to single out a special clinical variant of APS manifesting with generalized ischemic lesions of the organs as a result of arterial/arteriolar thrombosis. Irrespective of its nature, APSN has common characteristic features--combination of AH, persistent renal dysfunction and transitory hypercreatininemia--correlating with development of arterial thrombosis; therefore, this pathology can be considered as a variant of thrombotic vascular lesion of the kidneys.