Correspondence

Tests for HIV in Lupus

N Engl J Med 1994; 331:881September 29, 1994

Article

To the Editor:

Jindal et al1 described a woman with systemic lupus erythematosus who was receiving hemodialysis and was seropositive for the human immunodeficiency virus type 1 (HIV-1) by both enzyme-linked immunosorbent assay (ELISA) and Western blotting, with a low CD4+ cell count but no evidence of HIV-1 infection by viral culture, antigen testing, and the polymerase-chain-reaction test. The authors concluded that false positive serologic results may occur in people with lupus and end-stage renal disease, perhaps related to the presence of autoantibodies. However, the authors did not explain the patient's low CD4+ cell count (130 per cubic millimeter).

We analyzed serum samples from 224 patients with a diagnosis of autoimmune disorders for reactivity against HIV-1, human T-cell lymphotropic virus type I (HTLV-I), and HTLV-II proteins using both specific ELISAs (for HIV, Enzygnost, Behring, Marburg, Germany; and for HTLV-I and HTLV-II, BioKit, Barcelona, Spain) and Western blotting (for HIV, Bioblot Plus, BioKit; and for HTLV-I and HTLV-II, in-house blots with lysates from viral cultures on MT2 and MOT cells, respectively). The patients included 159 with lupus, 23 with primary antiphospholipid syndrome, 20 with primary Sjogren's syndrome, 7 with polymyositis, and 5 with scleroderma.

No samples were repeatedly reactive on ELISA or fulfilled the World Health Organization criteria (presence of bands reactive against at least two envelope antigens) for HIV-1 positivity on Western blotting. However, indeterminate patterns of reactivity for HIV-1, HTLV-I, and HTLV-II on Western blot analysis were seen sporadically (8.9 percent, 10.3 percent, and 7.6 percent of the samples, respectively) (Table 1Table 1Serum Samples from Patients with Autoimmune Disorders Showing Indeterminate Patterns of Reactivity for Retroviruses on Western Blotting.). All were negative on ELISA. The reactive bands most likely represented nonspecific reactivity. On Western blotting for HIV-1, p24 and p68 were the most frequently seen bands, whereas p24 and p19 were the most common on HTLV-I and HTLV-II Western blots. Reactivity against HIV-1 envelope bands was seen in only two patients (one with scleroderma and one with systemic lupus erythematosus), and in both the gp120 band was the only one observed.

Our results do not support the hypothesis of Jindal et al. that autoantibodies in autoimmune disorders such as systemic lupus erythematosus produce false positive results for HIV-1 with currently available ELISAs and Western blotting. Since false negative results have been described for the polymerase-chain-reaction test, viral culture, and antigen testing in HIV-1-infected persons and since the patient described by Jindal et al. had a low CD4+ cell count, it is hard to exclude HIV-1 infection on the basis of their results.

Vicenc Soriano, M.D., Ph.D.
Instituto de Salud Carlos III, 20829 Madrid, Spain

Josep Ordi, M.D., Ph.D.
Hospital Vall d'Hebron, 08035 Barcelona, Spain

Josep Grau, M.D., Ph.D.
Hospital Clinic i Provincial, 08036 Barcelona, Spain

1 References

1. 1

   Jindal R, Solomon M, Burrows L. False positive tests for HIV in a woman with lupus and renal failure. N Engl J Med 1993;328:1281-1282
   Full Text | Web of Science | Medline