Antiphospholipid Syndrome Nephropathy Related Disease Diagnosed by Assessing Phosphatidylserine-dependent Antiprothrombin Antibodies

Lupus nephritis and related renal disease: review from case series

Renal lesions due to systemic lupus erythematosus (SLE) are defined as lupus nephritis (LN), a renal disease characterized by the deposition of immunoglobulin (Ig)G-based immune complexes in the kidney and the appearance of double-stranded DNA and Smith antibodies. In particular, deposition of IgG3, which has strong complement binding properties, under the endothelium or in the mesangium activates the classical complement pathway of C1q, C4, and C3, leading to renal damage. This step is followed by migration of inflammatory cells, including neutrophils and monocytes, which induce inflammation in the glomerular capillaries and cause mesangiolysis and endothelial cell damage, resulting in endocapillary proliferative nephritis. LN is classified as class I to IV depending on the degree of inflammation or as class V in cases of subepithelial deposition of immune complexes in glomeruli. Deposition in the renal small arterioles by the same mechanism induces thrombus formation, resulting in lupus vasculopathy. Deposition in the tubular basement membrane and peritubular capillaries leads to tubulointerstitial lupus nephropathy. The appearance of antiphospholipid antibodies leads to acute and chronic forms of antiphospholipid antibody nephropathy (APSN) due to thrombus formation. This article reviews cases of the typical diverse renal lesions in LN.

A case of hypertensive emergency with alveolar hemorrhage and thrombotic microangiopathy

A 28-year-old woman with a 5-year history of untreated hypertension was admitted for respiratory distress, hemoptysis, and retinopathy. Computed tomography showed diffuse plaques in both lung fields. Acute kidney injury, hemolytic anemia, and thrombocytopenia were noted. Kidney biopsy showed thrombosis with fibrinoid necrosis and edematous intimal thickening and luminal narrowing of the small renal artery, indicating thrombotic microangiopathy; the majority of glomeruli were collapsed. After 8 weeks of treatment with antihypertensive drugs, serum creatinine decreased to 1.0 mg/dL, and the patient recovered. In the absence of any other underlying disease, malignant nephrosclerosis associated with a hypertensive emergency was diagnosed.

Antiphospholipid Syndrome Nephropathy with Acute Thrombotic Microangiopathy after Renal Transplantation

We experienced a 36-year-old man with lupus nephritis and antiphospholipid syndrome (APS) who received a donor kidney from his father. Twenty-two months after transplantation, at a time of poor adherence to immunosuppressants and warfarin, the patient developed sudden graft loss due to hemolytic uremic syndrome with rapid deterioration of renal function, thrombocytopenia, and hemolytic anemia. A kidney biopsy showed thrombotic microangiopathy (TMA) related to platelet thrombus formation; however, there was no recurrence of lupus and no findings suggestive of post-transplant rejection, so acute TMA associated with APS was thought to be the cause of the graft loss. This case highlights the importance of instructing patients with lupus nephritis to adhere to treatment with warfarin, a therapeutic drug for APS.