Abstract: FR-PO632
Thrombotic Microangiopathy as a Presentation of Paroxysmal Nocturnal Hemoglobinuria and Lupus Nephritis
Session Information
- Glomerular Diseases: Lupus and Vasculitis
November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1302 Glomerular Diseases: Immunology and Inflammation
Authors
- Calderon Garcia, Clementina Elizabeth, Hospital Civil de Guadalajara Unidad Hospitalaria Fray Antonio Alcalde, Guadalajara, Jalisco, Mexico
- Navarro Blackaller, Guillermo, Hospital Civil de Guadalajara Unidad Hospitalaria Fray Antonio Alcalde, Guadalajara, Jalisco, Mexico
- Chavez, Jonathan, Hospital Civil de Guadalajara Unidad Hospitalaria Fray Antonio Alcalde, Guadalajara, Jalisco, Mexico
Introduction
Thrombotic microangiopathy (TMA) characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ injury. Paroxysmal nocturnal hemoglobinuria (PNH) characterized by intravascular hemolytic anemia, thrombosis, bone marrow dysfunction and hypercoagulability. Systemic lupus erythematosus (SLE) is an autoimmune multisystemic disease. SLE associated with PNH is very rare.
We present the case of a man who presented TMA, secondary to lupus nephritis (LN) with PNH both entities coexisting.
Case Description
A 48-year-old man with acute kidney injury with creatinine 13mg/dl, urea 148mg/dl, hemoglobin 6g/dl and 56,000 platelets, with peripheral blood smear showing the presence of schistocytes, COOMBS direct negative, low haptoglobins, ANAs 1:640, low C3 and normal C4 levels. ADAMS 13 activity >17%, Shiga toxin and ANCAS negative. Anti-double chain, Anti-SM, lupus anticoagulant, anti cardiolipins, and anti B2 glycoprotein antibodies negatives. HBV, HCV, and HIV serologies negatives. Kidney ultrasound was normal. SLE was diagnosed, requiring hemodialysis. Renal biopsy was performed, reporting class II LN with acute tubulointerstitial nephritis and autoimmune TMA(Image).
Given the persistence of anemia and thrombocytopenia, PNH phenotype was addressed, and monocytes were identified as CD59 8.7%TYPE II, CD59 23.3% TYPE III.
Discussion
PNH has reduced or absent glycosylphosphatidylinositol (GPI)-anchored proteins on the cell surface. Loss of the GPI-linked complement inhibitors, CD55 and CD59 on erythrocytes leads to chronic or paroxysmal intravascular hemolysis.
In our patient, we found a deficient CD59 pattern that can also be observed in SLE or hemolytic anemias. Therapeutics can be directed by targeting complement protein C5, eculizumab is a treatment option that has been shown to significantly reduce hemolysis and thus hemolysis-related side effects in PNH cases.