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Show / oll", al of ( lllllcol N,,",,'- ol'l, tllIlllllllloXY 12( 1): 8- 9,1992. Editorial Comment 19 1992 Raven Press, Ltd., New York Rapid Response of Syphilitic Optic Neuritis to Posterior Sub- Tenon's Steroid Injection and Bilateral Optic Neuropathies with Remission in Two HIV- Positive Men The two papers in this issue, the first by Newman and Lessell and the second by Tomsak, Lystad, Katirji, and Brasse!' impress us with the fact that neuro- ocular syphilis is a disease that not only won't go away but continues to present ever increasing challenges- both diagnostic and therapeutic- to the clinician. Pertinent to the paper " Bilateral optic neuropathies with remission in two HIV- positive men" is an extremely important report by Haas et al. ( 1) from the Department of Medicine, University of California, the San Francisco Department of Public Health, and from the Centers for Disease Control in Atlanta. The term " serological test for syphilis" is really inadequate because there are many different blood tests used in the serodiagnosis of this disease. However, the tests fall into two basic groups. In the first are the reagin, or nonspecific, tests, the RPR ( rapid plasma reagin) or VORL being the two most commonly used at this time. In the second group are the treponema!' or specific, tests, with the FTA- ABS ( fluorescent treponemal antibody absorption) and the MHA- TP ( microhemagglutination assay for antibodies to Treponema pallidum) being the two most frequently used in this country. Another specific test, the TPI ( Treponema pa/ lidum immobilization), is difficult to obtain in the United States at this time. lt is known that over 90% of persons infected with syphilis will continue to have reactive test results with the treponemal tests even after adequate therapy. Many clinicians consider that a nonreactive treponemal test ( i. e., FTA- ABS or MHA- TP) shows that 8 there was no prior syphilis infection; this is a good general rule, although there have been rare exceptions reported_ However, Haas et al. ( 1) performed an extremely valuable study that should be carefully scrutinized by an physician encountering neuro- ophthalmological patients. They studied two groups of homosexual men who had serum samples stored in the University of California AIDS serum bank. One group had symptomatic HIV infection and had been followed between 1982 and 1985. The other group were either HIV seronegative or seropositive but were asymptomatic in 1983- 1984. The records of all patients with a self- reported history of syphilis were reviewed retrospectively. Patients were included in this study if their history of syphilis could be documented by records maintained in the San Francisco Department of Public Health. Patients were excluded if their history of syphilis was not so documented, if there were no records of a previously reactive treponemal test, or if a treponemal test had not been done on entry into the serum bank. The Department of Public Health maintains records of all syphilis cases reported in San Francisco County since 1975. Of 324 persons in the two longitudinal studies, 191 gave a self- reported history of syphilis. Seventy- eight individuals were excluded because a prior episode of syphilis was not documented by the Department of Public Health. The syphilis serology of 109 homosexual men with a documented history of treated syphilis was compared with records of prior results and confirmed on stored EDITORIAL COMMENT 9 REFERENCES Ocular penetration of erythromycin after injection in subtenon's space J. L. Smith, M. D. Editor Miami, Florida 1. Haas L Bolan G, Larsen SA, Clement MJ, Bacchetti P, Moss AR. Sensitivity of treponemal tests for detecting prior treated syphilis during human immunodeficiency virus infection. , Illfect Dis 1990; 162: 862-- 6. 2. Lukehart SA, Hook EW, Baker- Zander SA, Collier AC, Critchlow CW, Handsfield HH. Invasion of the central nervous system by Treponema pallidum: implications for diagnosis and treatment. 3. Smith JL, McCrary JA, Bird AC, et al. Subtenon steroid injection for optic neuritis. TrailS Am Acad Ophth Oto 1970; 74: 1249- 53. 0.23 IJ- g/ ml 0.93 IJ- g/ ml 1.20 IJ- g/ ml 35.0 IJ- g/ g Sample Concentra tion Serum Vitreous humor Vitreous humor Optic nerve Although a different pharmacologic agent was used for this bioassay ( i. e. an antibiotic rather than a steroid drug), the detection of a tissue level more than 30 times as high in the optic nerve itself as compared to the intraocular fluids 75 minutes after a subtenons injection, certainly establishes the fact that this route of administration can effectively give high tissue levels of a pharmacologic agent in the optic nerve itself. The " take home" lesson from the Haas and Tomsak studies is simply this- don't be satisfied with a serum VORL and a serum FTA- ABS test on your patient. Take a meticulous history asking specifically for prior venereal infections with emphasis on syphilis. If the latter history is positive, you should strongly consider treating the patient for syphilis, particularly if the amount of therapy is in doubt and particularly if the patient is HIVpositive. In the patient on intravenous penicillin therapy for syphilis, concomitant administration of 1 cc of aqueous triamcinolone ( Kenalog) by the subtenon's route, using a # 25 needle, 5/ 8" long, may be an important adjunct in the total treatment regimen. serum samples. None of the HIV- seronegative individuals lost reactivity to a treponemal test. Seven percent of the HIV- seropositive asymptomatic individuals lost reactivity to a treponemal test. However, 38% of persons with symptomatic HIV infection had loss of reactivity to a treponemaI test. This careful study eloquently demonstrates that finding a nonreactive serum FTA- ABS or serum MHA- TP test in an HIV- positive person may not identify those previously infected with Trepollema pallidwll. That the phenomenon of losing seroreactivity to the FTA- ABS or MHA- TP test in a person with an unequivocally documented history of having had syphilis in the past may occur in nearly 40% of patients with AIDS is obviously of great clinical importance. Despite the fact that the HIVseropositive patients reported by Newman and Lessell had nonreactive serum and spinal fluid VORL and FTA- ABS tests, the patients were treated with large doses of intravenous penicillin. This decision appears to show excellent clinical judgment- in fact, both patients subsequently showed improvement in visual function after this treatment. The chronologic relationship between penicillin therapy and visual improvement might vary, but the possibility that the patients had seronegative syphilis has to be considered in such cases. Finally, in the report of Tomsak et al., the use of subtenon's steroids in a patient being treated with penicillin for syphilitic optic neuritis appeared to be particularly helpful. One must recall that steroids alone can facilitate the progression of syphilitic disease, just as they can in such other granulomatous diseases as tuberculosis and fungal infections. However, the dose of a pharmacologic agent that can enter the optic nerve when administered by the subtenon's route can be truly impressive. An interesting experiment documented this phenomenon ( 3). A 72- year- old man was hospitalized for enucleation of a blind, painful eye. Just prior to surgery, he was given 1 ml ( 50 mg m) of injectable erythromycin ( Ilotyin) by subtenon's injection. The eye was removed 75 minutes later. In the operating room, specimens of vitreous, a portion of the optic nerve, and a match serum sample were obtained. These were all tested by bioassay at Eli Lilly and Company and revealed the following: JGin Neuro- ophthalmol, Vol. 12, No. 1. 1992 |