False positive VDRL (BFP-STS) and systemic lupus erythematosus; new data in clinico-laboratory associations

To investigate the relationships between clinical features and serological parameters in systemic lupus erythematosus (SLE) patients with false positive venereal disease research laboratory (VDRL) test (BFP-STS) and those without.

The records of 74 patients with SLE were reviewed. These were divided on the basis of the presence of a biologically false positive serological test (BFP-STS) (n = 18) or its absence (n = 56). The clinical features and serological parameters were subsequently evaluated in each group.

A biologically false positive serological test was found in 18 patients (24.5%). Clinically, they had a significantly higher frequency of malar rash (P < 0.02), hemolytic anaemia (P < 0.02) and SLE-related antiphospholipid (APL) syndrome (P < 0.02). Neuropsychiatric lupus was more frequent in the group without BFP-STS. Moreover, subacute cutaneous LE (SCLE), Raynaud's phenomenon, livedo reticularis (LR) and cardiopulmonary complications were present only in the latter group. There was no significant association between BFP-STS and other autoantibodies including Extractable nuclear antigen (ENAs), however, there was a significant association with C3 hypocomplementemia (P < 0.05). Half of the patients with BFP-STS were positive for anticardiolipin antibodies (aCL Abs) vs. 28% in the negative group (P = NS).

The study suggests that the clinical and serological relevance of BFP-STS in lupus patients may vary from those described in relation to other antiphospholipid determinants. Our patients appeared to have sparing of certain major organ systems, yet there was a greater tendency to developing Antiphospholipid (APL) syndrome and hemolytic anaemia.