V. This text will supply you with necessary information.

Head the text and find answers.

1. Why is it necessary to make a complete blood count as a part of initial evaluation?

2. How often should the doctor perform standard tests of renal and liver function?

3. Why is it necessary to repeat annually a nonspecific test for syphi­lis?

4. Is it recommended to perform testing for antibody to Toxoplasma?

Primary care for hiv infection Part II

Diagnostic studies

Tests recommended for evaluating the patient with newly diagnosed HIV infection are useful in estimating the likely rate of progression, in determining appropriate therapy, and in monitoring both the response to therapy and treatment toxicities.

A complete blood count with differential analysis of white cells should be obtained as part of the initial evaluation, and thereafter at intervals that depend on the stage of disease and on the medications administered. A mild anemia often develops as HIV disease progresses, and macrocyto- sis is commonly seen in patients treated with zidovudine.

When anemia is associated with other cytopenias, infection or malig­nancy in the bone marrow should be considered. An immune-mediated thrombocytopenic purpura has been associated with HIV infection; the thrombocytopenia may improve in response to antiretroviral therapy. Leukopenia is commonly seen in patients with HIV disease and may become more pronounced during zidovudine therapy. Neutropenia may also develop, but it is less severe than that seen in cancer patients receiv­ing chemotherapy and is usually well tolerated. Experienced clinicians will generally continue zidovudine therapy despite neutrophil count does not continue to fall.

Standard tests of renal and liver function and studies of serum elec­trolytes, glucose, total protein, and albumin should be performed as part of the initial evaluation and at least once a year thereafter - more often if symptoms develop. A nonspecific hypergammaglobulinemia has been described in patients with HIV disease; it may be a sign of poor progno­sis. Hypoalbuminemia is also thought by some authorities to signal poor prognosis. The liver function tests are useful in diagnosing concurrent hepatitis and in monitoring drug toxicities.

Patients should also be screened for past hepatitis В infection and those who are not previously infected or immune should be vaccinated. Although prior hepatitis С infection is very common in intravenous drug users, there is no approved treatment for patients with HIV disease and chronic hepatitis C. Routine testing for hepatitis С is therefore not rec­ommended. Screening for hepatitis A is also unnecessary.

A nonspecific test for syphilis (RPR or VDRL), with confirmatory specific treponemal testing as needed, should be part of the initial evalu­ation and should be repeated annually in patients who continue high-risk sexual behavior or needle-sharing. In the absence of well-designed clini­cal trials evaluating various treatment approaches, the optimal manage­ment of syphilis in the setting of HIV disease remains uncertain. Patients with primary or secondary syphilis should receive a once-a-week intra­muscular injection of benzathine penicillin (2,4 million units) for at least three weeks. The concurrent administration of probenecid may double the levels of penicillin in the cerebrospinal fluid and should therefore be con­sidered.

There is general agreement that examination of the cerebrospinal fluid is mandatory in HIV-seropositive patients with latent syphilis. The role of CSF examination in HIV-seropositive patients with early syphilis remains controversial. Arguments against it include the observation that patients may have treponemes in the spinal fluid even if laboratory analy­sis of the fluid is normal. Then, too, HIV infection itself is often the cause of an elevation of proteins in the CSF (along with a pleocytosis). Moreover, central nervous system infections other than syphilis may be responsible for any CSF abnormalities. HIV-seropositive patients with syphilis of any stage also require close monitoring of nontreponemal tests. There should be a fourfold decrease in the liter by six months after the completion of treatment. Serial lumbar puncture should be performed at three- to six-month intervals until the VDRL test of the cerebrospinal fluid is negative.