Histopathology and genotyping in infectious spondylitis of HIV- and HIV+ patients.
Approximately 2 million South Africans are HIV/TB coinfected, and many develop skeletal disease. The resurgence of spinal tuberculosis, including atypical forms, is due largely to HIV-associated immune suppression. We investigated the impact of HIV coinfection on the histological features of the disease and the occurrence of atypical opportunistic organisms in infectious spondylitis in an HIV/TB endemic region. We analyzed blood and tissue biopsies from 60 patients with tuberculous spondylitis. Investigations included full blood counts, CD4/CD8 counts, HIV-1 serology and RNA quantification (tissue and plasma), acid-fast bacilli localization and routine TB culture, histopathologic evaluation of biopsies, and bacterial genotyping using the 16S rDNA gene. Twenty-two patients (37%) were HIV positive with a mean age of 29 years (range, 2-65 years). Forty-one (68%) tissue specimens were culture negative for Mycobacterium tuberculosis (Mtb), although nontuberculous mycobacteria (NTM) were identified in three HIV-negative patients. Histopathologic features were characteristic of TB infection in 91.4% of all specimens tested and 100% of the HIV-infected group. Genotyping of 10 culture-positive isolates identified Mtb (3/10), NTMs (2/10), and environmental bacilli (3/10). Our observations suggest HIV-induced immune suppression impacts the histological and clinical features of infectious spondylitis but has no impact on the incidence of NTMs in this setting.
Danaviah
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Molecular Virology Laboratory, Africa Centre for Health and Population Studies, UKZN, Congella, South Africa.
Govender
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Cassol
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D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005260:Female; D005838:Genotype; D018023:HIV Seronegativity; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D013019:South Africa / Q000453:epidemiology; D013166:Spondylitis / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D018709:Statistics, Nonparametric; D014399:Tuberculosis, Spinal / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology*
D004269:DNA, Bacterial; D004275:DNA, Ribosomal