Kidney disease associated with primary antiphospholipid syndrome: clinical signs and histopathological features in an case experience of five cases.
BACKGROUND
The primary antiphospholipid syndrome (PAPS) is characterized by the presence of circulating antiphospholipid antibodies, clinically associated with blood hypercoagulability. Renal involvement in course of PAPS is very frequent, although the true prevalence of PAPS-correlated kidney disease is difficult to estimate.


METHODS
We reviewed 270 consecutive renal biopsies examined in our Nephrology Division of Bari University Hospital between 1998 and 2004 to identify those performed in patients with PAPS.


RESULTS
We identified five biopsies performed in patients with PAPS. In three patients the diagnosis of PAPS was made at onset of the kidney disorder, while in the other two cases the initial diagnosis was primary focal segmental glomerulosclerosis (FSGS). In these cases the subsequent finding of positive antiphospholipid antibodies reoriented the diagnosis toward PAPS-correlated nephropathy. The clinical onset of kidney disease consisted of acute renal failure in three patients and urinary abnormalities in the other two. Histological examination of renal biopsies showed vascular lesions (intimal fibrous hyperplasia, arteriolar hyalinosis, double outline of the capillary walls) in four patients. Focal segmental glomerulosclerosis was present in four patients, two of whom showed double outline of the capillary walls. All patients had tubulo-interstitial lesions, while immunofluorescence was positive in only two patients. All patients preserved stable renal function throughout follow-up (mean value: 10.6 years, range 4 months-24 years). The prevalence of PAPS-correlated nephropathy in our population was 1.85%


CONCLUSIONS
Our data confirm that PAPS-associated nephropathy has slow progression and rarely leads to end-stage renal failure. The prevalence of PAPS-correlated nephropathy is likely underestimated because some patients with a diagnosis of primary focal sclerosis may actually be affected by PAPS.
Saracino
A
A
Department of Internal and Public Medicine, Division of Nephrology, University of Bari, Italy. asaracino@inwind.it
Ramunni
A
A
Pannarale
G
G
Coratelli
P
P
D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000097:blood; D016736:Antiphospholipid Syndrome / Q000097:blood / Q000150:complications* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005923:Glomerulosclerosis, Focal Segmental / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007668:Kidney / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies
D017152:Antibodies, Antiphospholipid