Abstract:

Objective To investigate the features of magnetic resonance imaging (MRI) of the acquired immunodeficiency syndrome (AIDS) patients complicated with cerebral tuberculosis (TB) and its relationship with CD4 ⁺ T-cell count. Methods A retrospective analysis was conducted. The related clinical information and data were collected from 46 AIDS patients complicated with cerebral TB, who were hospitalized at Beijing Ditan Hospital from January 2014 to December 2017. Those information and data were analyzed and the patients’ MRI features were summarizes; the difference of CD4 ⁺ T-cell count between the patient groups of brain parenchymal TB and meningeal TB was compared by using Mann-Whitney test; the difference of MRI features in two groups of the patients with CD4 ⁺ T cells ≥100/μl and <100/μl were compared by using χ ² test, such as the lesion location, scope, size, shape, the way of enhancement, as well as the situation combined with other organ TB, etc.; the relationship between the CD4 ⁺ T-cell count and the lesion size, the way of enhancement was also analyzed. Results Among 46 enrolled AIDS patients with cerebral TB, the CD4 ⁺ T-cell count was significantly lower in the patients with brain parenchymal TB (47 (20.5,131.5)/μl) than that in the patients with meningeal TB (153 (130.5,228.5)/μl) (Z=-2.37, P=0.018). In the patients with CD4 ⁺ T cells ≥100/μl, the proportion of meningeal TB was 19.6% (9/46) and the proportions that the lesions located in cerebral basal cistern, cerebral lateral fissure cistern and cerebral sulcus were 17.4% (8/46), 13.0% (6/46) and 13.6% (6/46) respectively, which were much higher than those (4.3% (2/46), 2.2% (1/46), 2.2% (1/46), 2.2% (1/46) respectively) in the patients with CD4 ⁺ T cells <100/μl (χ ²=7.62, P=0.006; Fisher’s exat test: P=0.001, 0.008 and 0.008, respectively); the proportion that the lesions located in cerebral cortex was 19.6% (9/46) which was much lower than that (47.8%, 22/46) in the patients with CD4 ⁺ T cells <100/μl (Fisher’s exat test, P=0.037). When the lesion diameter was 3-5 mm, the point enhancement was found on MRI (136 lesions, 47.1%), while the ring enhancement was found on the MRI when the lesion diameter was more than 5 mm (89 lesions, 30.8%); the difference was statistically significant (χ ²=105.36, P<0.001). In the patient group with brain parenchymal TB, most of their lesions located in cerebral cortex and the point or ring enhancements were found (88.6%, 31/35); in the patient group with meningeal TB, the meningeal thickening enhancement was found on MRI (81.8%, 9/11); the lesions were all in cluster distributions in both brain parenchyma TB (17.4%, 8/46) and meningeal TB (21.7%, 10/46), the difference was statistically significant (χ ²=4.13,P=0.042). Conclusion The features of MRI in AIDS patients complicated with cerebral TB are closely related to their CD4 ⁺ T-cell counts. When the number of CD4 ⁺ T-cell is <100/μl, the brain parenchymal TB is the major type and the lesions are more likely to locate in cerebral cortex; when the number of CD4 T-cell is ≥100个/μl, the meningeal TB is the major type and the lesions are more likely to locate in cerebral basal cistern, cerebral lateral fissure cistern and cerebral sulcus; the point enhancement is observed when the lesion diameter is <5 mm, while the ring enhancement is found when the lesion diameter is >5 mm.

Key words: Acquired immunodeficiency syndrome, Tuberculosis, central nervous system, Magnetic resonance imaging, CD4 lymphocyte count, Causality