HDCN Ask the Professor -- Pregnancy, renal failure, antiphospholipid antibodies

Question: A young woman lost her baby during the last week of her first gestation, one year ago. At that time she became oliguric and subsequently never regained renal function. The diagnosis at that time was hemolytic uremic syndrome of pregnancy. Now, 1 year later, the patient is on hemodialysis. A workup showed antiphospholipid IgG antibody titer over 40. One thought was to anticoagulate her with low molecular weight heparin daily, since the size of the kidneys remains normal. Does anyone have experience with such cases ?

Jose Roberto Rocha, M.D. (Rio de Janeiro, Brazil)

Response by Dr. Daniel Kniaz, Lutheran General Hospital, Des Plaines, IL
A relationship between antiphospholipid antibodies (APA) and severe preeclampsia or postpartum or hemolytic uremic syndrome has been reported by Kincaid-Smith and by us. Occasionally, renal failure, severe or malignant hypertension, and microangiopathic hemolytic anemia are associated with diffuse fibrin deposits in glomerular capillaries and arterioles; a process distinctly different from thromboembolic complications in large vessels seen in patients with other antiphospholipid syndromes (APS).

Based on case reports, plasma exchange therapy (if performed early) may result in a rapid reversal of some or most of this pathological process. Anticoagulation with high dose heparin followed by prolonged prophylaxis with warfarin has been recommended for the treatment of acute thrombosis associated APS. Plasma exchange therapy and high dose steroids may be beneficial if thrombosis recurs while on anticoagulant therapy, but only if initiated early. In women with a history of fetal loss and APAs, low-dose heparin, aspirin, or prednisone has been tried to prolong future pregnancies. However, outcomes have not been consistently better and Kincaid-Smith raised concern that prolonging pregnancy may aggravate the renal disease.

The young woman referred to may, in fact, have HUS or preeclampsia associated with APAs. However, the APA titers were apparently only measured after she had been on dialysis approximately 9 months, and dialysis itself has been associated with an increased prevalence of APA. Thus, it is possible that high APA titers in this patient occurred after she started dialysis and were not associated with her primary renal disease.

If APA was associated with this woman’s renal failure, there is no evidence that anticoagulation or immunosuppressive therapy would benefit her at this late point in her illness. If, on the other hand, she develops other occlusive vasculopathies or recurrent access thrombosis, prolonged anticoagulation would be indicated but at full (and not low) doses. References

1. Kniaz D, Eisenberg G, Elrad H, et al: Postpartum hemolytic uremic syndrome associated with antiphospholipid antibody. Am J Nephrol 1992;12:126-133.
2. Kincaid-Smith P, Nicholls K: Renal thrombotic microvascular disease associate with lupus anticoagulant. Nephron 1990;54:285-288.
3. Prakash R, Miller C, Suke W: Anticardiolipin antibody in maintenance hemodialysis patient association with recurrent arteriovenous graft thrombosis. (abstract); JASN 1994:5(3):425.

(November, 1995)