TreatmentUpdate 55 - Vol. 7, No. 1 - January 1995
Sean Hosein

Researchers in Atlanta studied the effect of standard treatment for neurosyphilis in 11 HIV-infected subjects (9 male, 2 female). The subjects were all adults and tested 'positive' for syphilis on standard tests (listed in section A). Medical staff performed a spinal tap to get a sample of CSF (cerebrospinal spinal fluid; in which the brain and spinal cord float). Technicians tested the CSF samples for the microbe that causes syphilis as well as antibodies that suggest syphilis. Subjects had the following signs/symptorns of neurosyphilis:

- eye inflammation - swollen/damaged retina - stroke - life-threatening brain infection - "behavioural changes" (the researchers did not provide details about this symptom)

Some subjects also had other symptoms-rashes on the hands and feet. Three subjects also had lost hair on parts of their bodies. About half the subjects had a CD4+ cell count of 344 cells. Doctors gave subjects intravenous penicillin G, 18 million to 24 million units daily for 10 days.

* REACTIONS TO TREATMENT

Six weeks after receiving treatment technicians analysed blood and CSF samples. Using one test called VDRL, it appeared that 7 of 11 subjects recovered from their infection. In 2 of the 4 remaining subjects, it appeared that the infection was not getting worse while in 2 others the infection seemed to get worse. The doctors suggested that the immune systems of these 4 subjects could not contain the infection.

* SIX MONTHS LATER

Eventually, it appeared that 4 subjects recovered. In 6 subjects analysis of CSF sarnples revealed high levels of white blood cells-suggesting continued infection. Three of these subjects who received additional treatment continued to have high levels of white blood cells in their CSF. Overall, 10 of the 11 subjects had their signs/symptoms of neurosyphilis clear. One subject had symptoms of neurosyphilis (including blindness) that became worse despite aggressive treatment (24 million units/day of penicillin for 2 weeks). By the sixth month she developed more symptoms such as headaches and she had difficulty controlling muscles on the right side of her body. Doctors gave her another 2 week course of "high-dose" penicillin but she "died 2 months later."

* WHAT TO DO?

High levels of white blood cells in the CSF samples from these HIV-infected subjects suggested that T. pallidum infection continued. Doctors are not sure what to do for such patients. Some doctors wait several months to see if the level of white blood cells in the CSF falls. It may take between 6 and 12 months for this to happen. Using PCR (polymerase chain reaction), technicians found T. pallidum in only 3 of 11 subjects before they received antibiotic therapy. But this probably means that PCR is not "sensitive" enough because all subjects had signs/symptoms of neurosyphilis. Despite increasing the dose of penicillin, T. pallidum infection seemed to get out of control suggesting that this microbe is resistant to penicillin. It is not always clear which patients will recover. Indeed, 3 of the subjects in this trial whose infection became worse did not have the "lowest" CD4+ cell counts. The doctors in this study state that other anti- syphilis therapies need to be tested. As well, because of the difficulty in predicting who will recover from neurosyphilis, the doctors also state that patients with neurosyphilis need "intensive evaluation...including CSF examination, and very careful follow up."

REFERENCES:

1. Gordon SM, Eaton ME, George R, et al. The response of symptomatic neurosyphilis to higidose intravenous penicillin G in patients with Human Immunodeficiency Virus infection. New England Journal of Medicine 1994;331(22):1469-1473.

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Copyright © 1995 - TreatmentUpdate. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Editor, The Canadian AIDS Treatment Information Exchange, 555 Richmond St. West, Suite 505, Box 1104, Toronto, ON, M5V 3B1 • Phone: 416-203-7122 • Toll Free: 1-800-263-1638 • Fax: 416-203-8284  http://www.catie.ca