CONSULT ROUNDS: Anti-Phospholipid Syndrome and the Kidney

Renal abnormalities are present in approximately 7-9% of patients with primary anti phospholipid syndrome(PAPS).  Outcome and long-term follow-up usually are good. A large spectrum of renal thrombotic manifestations have been described in association with antiphospholipid antibodies, such as renal artery stenosis, renal infarction, renal vein thrombosis, acute or chronic thrombotic microangiopathy, and, more recently, the so-called “antiphospholipid antibodies nephropathy.”  Thrombosis can occur at any level of the renal vascular tree: Renal and intrarenal arteries, glomerular capillaries, and renal vein. Histologic findings show ischemic glomeruli and thrombotic lesions, without glomerular or arterial immune deposits on immunofluorescence. So besides TMA related findings, glomerular diseases can also be found with PAPS.

Other GNs that can be seen with PAPS is in this order:

Membranous GN
Proliferative GN
MCD-FSGS
C3 GN

The following two series in AJKD and CJASN suggest the varied degree of findings of glomerular and endothelial damage seen in the kidney with PAPS. 

https://www.ncbi.nlm.nih.gov/pubmed/12776272

http://m.cjasn.asnjournals.org/content/5/7/1211.full

In most patients, Lupus anticoagulant is positive (92.3%) along with b2 glycoprotein.
ANA is usually positive in low titer in >60% of patients whereas dsDNA might be only found in 30% of cases. Most patients have low complements levels( c3 and c4).

In the CJASN paper, all patients were treated with anticoagulation. Patients with MN were treated with steroids with addition of cyclophosphamide in two. Remission was achieved in two patients with MN; one was stable with mild proteinuria (0.5 g/d), and one patient was lost to follow-up. Both patients with diffuse proliferative glomerulonephritis were treated with corticosteroids plus cyclophosphamide with remission of nephrotic-range proteinuria. 

Eculizumab has been tried in one case report with PAPS associated TMA and another case with catastrophic PAPS.

Among them, renal involvement seems to be targeted in PAPS by other mechanisms such as immune complex deposition. Moreover, the heterogeneity of renal involvement confirms the presence of a continuum between SLE and PAPS  and suggests that a complete nephrologic workup should be performed in patients with signs of renal disease. Renal prognosis seems good if treated early as an autoimmune disease.