Herpes simplex virus type 2 encephalitis and concomitant cytomegalovirus infection in a patient with AIDS: detection of virus-specific DNA in CSF by nested polymerase chain reaction

Molecular analysis of cerebrospinal fluid in viral diseases of the central nervous system

The use of nucleic acid (NA) amplification techniques has transformed the diagnosis of viral infections of the central nervous system (CNS). Because of their enhanced sensitivity, these methods enable detection of even low amounts of viral genomes in cerebrospinal fluid. Following more than 10 years of experience, the polymerase chain reaction or other NA-based amplification techniques are nowadays performed in most diagnostic laboratories and have become the test of choice for the diagnosis of several viral CNS infections, such as herpes encephalitis, enterovirus meningitis and other viral infections occurring in human immunodeficiency virus-infected persons. Furthermore, they have been useful to establish a viral etiology in neurological syndromes of dubious origin and to recognise unusual or poorly characterised CNS diseases. Quantitative methods have provided a valuable additional tool for clinical management of these diseases, whereas post-amplification techniques have enabled precise genome characterisation. Current efforts are aiming at further improvement of the diagnostic efficiency of molecular techniques, their speed and standardisation, and to reduce the costs. The most relevant NA amplification strategies and clinical applications of to date will be the object of this review.

Necrotising herpetic retinopathy in patients with advance HIV disease

OBJECTIVES

To describe the presenting features, clinical and laboratory diagnosis, response to treatment, and outcome of necrotising herpetic retinopathy (NHR) in HIV infected patients.

METHODS

Retrospective case records/laboratory data review of five HIV infected patients presenting to the specialist HIV/AIDS unit at UCL Hospitals, London from April 1994 to August 1996 with a clinical diagnosis of NHR.

RESULTS

All patients had advanced HIV disease with a median CD4 count of 20.10(6)/1. Three patients had cutaneous varicella zoster virus (VZV) infection within the preceding 8 weeks. All had uniocular loss of visual acuity; one also had headache and another ocular pain. All had typical retinal appearances. VZV DNA was detected in cerebrospinal fluid of four patients (and in vitreous fluid of one of the four) and in vitreous fluid of one other. One patient refused therapy and rapidly became blind. Four patients received intravenous foscarnet with intravenous aciclovir for 6 weeks: three subsequently received oral famciclovir and one oral valaciclovir; two patients also had intravitreal injections of foscarnet. In none of the four did treatment bring about improvement in visual acuity, but in all four visual loss from retinitis was halted.

CONCLUSIONS

NHR occurs in HIV infected patients with advanced HIV disease and is strongly associated with evidence of VZV infection. With aggressive use of antiviral drugs the outcome is not uniformly poor.

Acute lumbosacral polyradiculopathy due to cytomegalovirus in advanced HIV disease: CSF findings in 17 patients

OBJECTIVES

To describe the abnormalities in CSF from HIV infected patients with acute lumbosacral polyradiculopathy (ALP) caused by cytomegalovirus (CMV) infection.

METHODS

Retrospective case notes and laboratory records were reviewed for 17 consecutive patients with CMV associated ALP admitted to specialist HIV/AIDS units at UCL Hospitals and Chelsea and Westminster Hospital.

RESULTS

Infection with CMV was confirmed by detection of CMV DNA by polymerase chain reaction amplification in 15 patients (all of whom were negative by culture), by culture in one patient, and by objective clinical response to anti-CMV treatment in one patient. Only nine patients had a CSF pleocytosis 28-1142 (median 150) cells/mm3; in seven there was a polymorphonuclear (PMN) leucocyte preponderance. Protein concentrations in CSF were moderately or considerably raised in 13 patients; CSF: plasma glucose ratios were < or = 50% in five patients. Two patients had no pleocytosis, normal CSF: plasma glucose, and normal or near normal protein values.

CONCLUSIONS

Abnormalities in CSF in CMV associated ALP are varied: only 50% of patients have a "typical" PMN preponderant pleocytosis. The diagnosis of this condition should not rely on demonstration of a PMN preponderant pleocytosis, but on identification of CMV DNA in CSF and the exclusion of other opportunistic infections and lymphoma in order that specific anti-CMV treatment may be instituted.