Anticardiolipin Antibodies in South African Patients with Lupus Nephritis: A Clinical and Renal Pathological Study

Abstract

Aims: This study was conducted prospectively to ascertain the prevalence of anticardiolipin antibodies (ACAs) in patients with lupus nephritis and to determine whether this subgroup of patients differed clinically and histologically from patients without the antibody. Patients and Methods: 40 SLE patients (26 Blacks, 14 Indians, 37 females, 3 males) with evidence of renal involvement underwent clinical assessment and percutaneous renal biopsy. Special investigations included: urinary protein quantitation; radioisotope glomerular filtration rate (GFR); complement levels, and antinuclear antibodies and ACAs. Histology was reviewed by a single senior pathologist blinded to the ACA results. In addition to the standard WHO classification, specimens were examined for intrarenal thrombosis. Results: The prevalence of ACA was 45% (18 of 40 patients). Thrombocytopenia was more frequent in patients with ACA (33 vs. 13.6%, p = 0.015). Patients with ACA did not differ from controls with regard to the incidence of thrombosis, neurological disorders, recurrent fetal loss, active disease and hypertension. Mean GFR and 24-hour urine protein (ACA vs. controls) were 51.3 versus 67 ml/min (NS) and 2.4 versus 3.7 g (NS), respectively. Intrarenal microvascular thrombosis (glomerular and arteriolar) occurred in 27.7% of ACA patients versus 9% of controls (p = 0.025). Apart from a higher incidence of class-III nephritis in the controls, standard histology (WHO classification) did not differ between the 2 groups. Conclusion: The prevalence of ACA in our patients with lupus nephritis was 45%. This subgroup did not differ from patients without the antibody apart from a higher incidence of thrombocytopenia and intrarenal microvascular thrombosis.

Antiphospholipid antibody profiles in lupus nephritis with glomerular microthrombosis: a prospective study of 124 cases

“…aPL, including LAC, aCL, and anti-β2GPI antibodies, are considered to be of pathogenic significance in thrombosis in APS and SLE patients, which makes them the most frequently examined factors in the investigation of the pathogenesis of GMT in LN. GMT has been found to be associated with LAC and/or aCL in LN patients in some studies [ 4 , 6 , 7 , 9 - 12 , 14 - 18 ], but not in others [ 5 , 8 , 19 - 21 ]. Kant and colleagues [ 4 ] examined 105 kidney biopsy specimens from LN patients and found that GMT was detected in 34 cases, among which 7 were LAC positive.…”

“…The laboratory criteria of update criteria for definite antiphospholipid syndrome (APS) includes the lupus anticoagulant (LAC), the anticardiolipin antibody (aCL), and the anti-β2 glycoprotein I (β2GPI) antibody [ 13 ]. GMT has been associated with aPL in LN patients in some studies [ 4 , 6 , 7 , 9 - 12 , 14 - 18 ], but not in others [ 5 , 8 , 19 - 21 ]. Recent studies of seven monoclonal immunoglobulin (Ig) G aCLs from two APS patients demonstrated that five aCLs reacted with several hemostatic and fibrinolytic proteases that share homologous enzymatic domains.…”

Association between antiphospholipid antibodies and factor Bb in lupus nephritis patients with glomerular microthrombosis

“…The presence of aPLs has been closely related to the development of thrombosis and pregnancy complications in antiphospholipid syndrome (APS). GMT has also been associated with aPLs in patients with LN in some studies, but the mechanism of aPL‐induced GMT is still a topic of controversy.…”

Renal Involvement in Antiphospholipid Syndrome

“…Most studies have reported poor renal prognosis in patients with SLE and coexisting APSN. However, Naiker et al reported a high prevalence of aPL in patients with SLE nephritis but did not found worse renal prognosis ( 60 ).…”