Real-time Polymerase Chain Reaction for Mycobacterium tuberculosis Meningitis is More Sensitive in Patients with HIV Co-Infection.

BACKGROUND: Tuberculous meningitis (TbM) is the most severe complication of extra pulmonary tuberculosis (Tb). There is a higher frequency of positive cerebrospinal fluid (CSF) cultures for Mycobacterium tuberculosis (MTb) in samples from human immunodeficiency virus (HIV) co-infected patients than in those from HIV-negative patients. We hypothesized that real time PCR assays for MTb (MTb qPCR) using CSF would be more sensitive in HIV co-infected patients owing to a greater MTb burden. The present study aimed to verify the diagnostic performance of MTb qPCR in CSF of TbM patients who either were co-infected with HIV or were HIVnegative. METHODS: A total of 334 consecutive participants with suspected TbM were divided into two groups: HIV co-infected and HIV-negative; each group was categorized into definite TbM, probable TbM, possible TbM, and TbM-negative subgroups based on clinical, laboratory and imaging data. We evaluated the diagnostic characteristics of MTb qPCR analysis to detect TbM in CSF by comparing the results to those obtained for definite TbM (i.e., positive MTb culture) and/or probable TbM in CSF, as gold standard. RESULTS: The sensitivity of MTb qPCR in the definite and probable subgroups of the HIV coinfected participants (n = 14) was 35.7%, with a specificity of 93.8%, negative predictive value (NPV) of 94.4%, and negative clinical utility index (CUI-) of 0.89. Results of the HIV-negative group (n = 7) showed lower sensitivity (14.3%) and similar specificity, NPV, and CUI-. CONCLUSION: The findings confirmed our hypothesis, despite the low sensitivity. MTb qPCR may significantly contribute to diagnosis when associated with clinical criteria and complementary examinations.

Progressive multifocal leukoencephalopathy in Zambia is caused by JC virus with prototype regulatory region.

There are only few documented cases of progressive multifocal leukoencephalopathy (PML) in Africa. Whether this is caused by a lack of JC virus (JCV) spread or alteration in the JCV genome is unknown. We characterized the clinical presentation, laboratory findings, and JCV regulatory region (RR) pattern of the first documented PML cases in Zambia as well as JCV seroprevalence among HIV+ and HIV- Zambians. We identified PML patients with positive JCV DNA PCR in their cerebrospinal fluid (CSF) among subjects enrolled in an ongoing tuberculous meningitis study from 2014 to 2016 in Lusaka. JCV regulatory region was further characterized by duplex PCR in patients' urine and CSF. Of 440 HIV+ patients, 14 (3%) had detectable JCV DNA in their CSF (age 18-50; CD4+ T cells counts 15-155 × 106/µl) vs 0/60 HIV- patients. The main clinical manifestations included altered mental status and impaired consciousness consistent with advanced PML. While prototype JCV was identified by duplex PCR assay in the CSF samples of all 14 PML patients, only archetype JCV was detected in their urine. All PML Zambian patients tested were seropositive for JCV compared to 46% in a control group of HIV+ and HIV- Zambian patients without PML. PML occurs among HIV-infected individuals in Zambia and is caused by CNS infection with prototype JCV, while archetype JCV strains are present in their urine. JCV seroprevalence is comparable in Zambia and the USA, and PML should be included in the differential diagnosis of immunosuppressed individuals presenting with neurological dysfunction in Zambia.

Tuberculous meningitis is associated with higher cerebrospinal HIV-1 viral loads compared to other HIV-1-associated meningitides.

To gain a better understanding of the immunopathogenesis of tuberculous meningitis (TBM) and identify potential diagnostic biomarkers that may discriminate TBM from other HIV-1-associated meningitides, we assessed HIV-1 viral load levels, drug resistance patterns in antiretroviral therapy (ART)-experienced patients with persistent viremia and soluble immunological analytes in peripheral blood and cerebrospinal fluid (CSF) of HIV-1 infected patients with TBM versus other meningitides. One hundred and three matched blood and CSF samples collected from HIV-1 infected patients with TBM or other meningitides presenting at a hospital in Durban, South Africa, from January 2009 to December 2011 were studied. HIV-1 RNA and 28 soluble immunological potential biomarkers were quantified in blood plasma and CSF. Viremic samples were assessed for HIV-1 drug resistance mutations. There were 16 TBM, 46 probable TBM, 35 non-TBM patients, and six unclassifiable patients. TBM and non-TBM patients did not differ in median plasma viral load but TBM patients had significantly higher median CSF viral load than non-TBM participants (p = 0.0005). No major drug resistance mutations were detected in viremic samples. Interleukin (IL)-1ß, IL-17, platelet derived growth factor (PDGF)-BB, granulocyte colony stimulating factor (G-CSF) and cathelicidin were significantly elevated in the CNS of TBM participants compared to other patients although these associations were lost after correction for false discovery. Our data suggest that TB co-infection of the CNS is associated with enhanced localized HIV-1 viral replication but none of the evaluated soluble immunological potential biomarkers could reliably distinguish TBM from other HIV-associated meningitides.

Inflammasome Activation Underlying Central Nervous System Deterioration in HIV-Associated Tuberculosis.

Tuberculous meningitis (TBM) is a frequent cause of meningitis in individuals with human immunodeficiency virus (HIV) infection, resulting in death in approximately 40% of affected patients. A severe complication of antiretroviral therapy (ART) in these patients is neurological tuberculosis-immune reconstitution inflammatory syndrome (IRIS), but its underlying cause remains poorly understood. To investigate the pathogenesis of TBM-IRIS, we performed longitudinal whole-blood microarray analysis of HIV-infected patients with TBM and reflected the findings at the protein level. Patients in whom TBM-IRIS eventually developed had significantly more abundant neutrophil-associated transcripts, from before development of TBM-IRIS through IRIS symptom onset. After ART initiation, a significantly higher abundance of transcripts associated with canonical and noncanonical inflammasomes was detected in patients with TBM-IRIS than in non-IRIS controls. Whole-blood transcriptome findings complement protein measurement from the site of disease, which together suggest a dominant role for the innate immune system in the pathogenesis of TBM-IRIS.

The diagnostic value of cerebrospinal fluid chemistry results in childhood tuberculous meningitis.

PURPOSE: Cerebrospinal fluid (CSF) hypoglycorrhachia and elevated protein is well-described in bacterial meningitis, but evidence for its differential diagnostic value in tuberculous meningitis (TBM) is lacking. We aimed to assess the diagnostic utility of CSF glucose, CSF to serum glucose ratio and CSF protein in children with suspected TBM. METHODS: We describe CSF glucose and protein values as well as CSF to serum glucose ratios in a prospective evaluation of TBM suspects seen at Tygerberg Children's Hospital, Cape Town, South Africa, from January 1985 to January 2014. RESULTS: Of 615 TBM suspects, 88 (14%) had microbiologically confirmed TBM, 381 (62%) 'probable' TBM and 146 (24%) 'non-TBM'. Mean absolute CSF glucose concentration was significantly lower in the microbiologically confirmed (1.87 ± 1.15 mmol/L) and 'probable' TBM (1.82 ± 1.19 mmol/L) groups compared to non-TBM (3.66 ± 0.88 mmol/L). A CSF glucose concentration of <2.2 mmol/L diagnosed TBM with sensitivity 0.68 and specificity 0.96. Sensitivity using a CSF to serum glucose ratio of <0.5 was 0.90. Mean CSF protein was significantly elevated in the microbiologically confirmed TBM (1.91 ± 1.44 g/L) and 'probable' TBM (2.01 ± 1.49 g/L) groups compared to the non-TBM (0.31 ± 0.31 g/L). A CSF protein >1 g/L diagnosed TBM with sensitivity 0.78 and specificity 0.94. CONCLUSION: Absolute CSF glucose values of <2.2 mmol/L and protein values of >1 g/L differentiated between TBM and non-bacterial meningitis with good specificity, although sensitivity was poor. A CSF to serum glucose ratio is more informative than the absolute value.

Diffusion tensor imaging study of white matter damage in chronic meningitis.

Tuberculous meningitis (TBM) and cryptococcal meningitis (CM) are two of the most common types of chronic meningitis. This study aimed to assess whether chronic neuro-psychological sequelae are associated with micro-structure white matter (WM) damage in HIV-negative chronic meningitis. Nineteen HIV-negative TBM patients, 13 HIV-negative CM patients, and 32 sex- and age-matched healthy volunteers were evaluated and compared. The clinical relevance of WM integrity was studied using voxel-based diffusion tensor imaging (DTI) magnetic resonance imaging. All of the participants underwent complete medical and neurologic examinations, and neuro-psychological testing. Differences in DTI indices correlated with the presence of neuro-psychological rating scores and cerebrospinal fluid (CSF) analysis during the initial hospitalization. Patients with CM had more severe cognitive deficits than healthy subjects, especially in TBM. There were changes in WM integrity in several limbic regions, including the para-hippocampal gyrus and cingulate gyrus, and in the WM close to the globus pallidus. A decline in WM integrity close to the globus pallidus and anterior cingulate gyrus was associated with worse CSF analysis profiles. Poorer DTI parameters directly correlated with worse cognitive performance on follow-up. These correlations suggest that WM alterations may be involved in the psychopathology and pathophysiology of co-morbidities. Abnormalities in the limbic system and globus pallidus, with their close relationship to the CSF space, may be specific biomarkers for disease evaluation.

Paradoxical Mycobacterium tuberculosis meningitis immune reconstitution inflammatory syndrome in an HIV-infected child.

Immune reconstitution inflammatory syndrome occurs in a subset of HIV-infected individuals as the immune system recovers secondary to antiretroviral therapy. An exaggerated and uncontrolled inflammatory response to antigens of viable or nonviable organisms is characteristic, with clinical deterioration despite improvement in laboratory indicators. We describe a fatal case of Mycobacterium tuberculosis meningitis immune reconstitution inflammatory syndrome in an HIV-infected child and review the literature.

TB meningitis in HIV-positive patients in Europe and Argentina: clinical outcome and factors associated with mortality.

OBJECTIVES: The study aimed at describing characteristics and outcome of tuberculous meningitis (TBM) in HIV-positive patients and comparing these parameters with those of extrapulmonary TB (TBEP) and pulmonary TB (TBP). METHODS: Kaplan-Meier estimation and Poisson regression models were used to assess the mortality following TB diagnosis and to evaluate potential prognostic factors for the 3 groups of TB patients separately. RESULTS: A total of 100 patients with TBM, 601 with TBEP, and 371 TBP were included. Patients with TBM had lower CD4 cell counts and only 17.0% received antiretroviral therapy (ART) at TB diagnosis. The cumulative probability of death at 12 months following TB was 51.2% for TBM (95% CI 41.4-61.6%), 12.3% for TBP (8.9-15.7%), and 19.4% for TBEP (16.1-22.6) (P<0.0001; log-rank test). For TBM, factors associated with a poorer prognosis were not being on ART (adjusted incidence rate ratio (aIRR) 4.00 (1.72-9.09), a prior AIDS diagnosis (aIRR=4.82 (2.61-8.92)), and receiving care in Eastern Europe (aIRR=5.41 (2.58-11.34))). CONCLUSIONS: TBM among HIV-positive patients was associated with a high mortality rate, especially for patients from Eastern Europe and patients with advanced HIV-infection, which urgently calls for public health interventions to improve both TB and HIV aspects of patient management.

Influence of antituberculosis drug resistance and Mycobacterium tuberculosis lineage on outcome in HIV-associated tuberculous meningitis.

HIV-associated tuberculous meningitis (TBM) has high mortality. Aside from the devastating impact of multidrug resistance (MDR) on survival, little is understood about the influence of other bacterial factors on outcome. This study examined the influence of Mycobacterium tuberculosis drug resistance, bacterial lineage, and host vaccination status on outcome in patients with HIV-associated TBM. Mycobacterium tuberculosis isolates from the cerebrospinal fluid of 186 patients enrolled in two studies of HIV-associated TBM in Ho Chi Minh City, Vietnam, were tested for resistance to first-line antituberculosis drugs. Lineage genotyping was available for 122 patients. The influence of antituberculosis drug resistance and M. tuberculosis lineage on 9-month mortality was analyzed using Kaplan-Meier survival analysis and Cox multiple regression models. Isoniazid (INH) resistance without rifampin resistance was associated with increased mortality (adjusted hazard ratio [HR], 1.78, 95% confidence interval [CI], 1.18 to 2.66; P = 0.005), and multidrug resistance was uniformly fatal (n = 8/8; adjusted HR, 5.21, 95% CI, 2.38 to 11.42; P < 0.0001). The hazard ratio for INH-resistant cases was greatest during the continuation phase of treatment (after 3 months; HR, 5.05 [95% CI, 2.23 to 11.44]; P = 0.0001). Among drug-susceptible cases, patients infected with the "modern" Beijing lineage strains had lower mortality than patients infected with the "ancient" Indo-Oceanic lineage (HR, 0.29 [95% CI, 0.14 to 0.61]; P = 0.001). Isoniazid resistance, multidrug resistance, and M. tuberculosis lineage are important determinants of mortality in patients with HIV-associated TBM. Interventions which target these factors may help reduce the unacceptably high mortality in patients with TBM.

Tuberculous syringomyelia in an HIV-infected patient: a case report.

A 37-year-old HIV-positive Gambian woman presented with spastic weakness of the right leg six years after receiving treatment for tuberculous meningitis (TBM). Magnetic resonance imaging (MRI) of the spine showed a multiloculated syrinx in the thoracic spinal cord extending from the T2 to the T11 level. Syringomyelia and syringobulbia have been reported as complications of TBM. We describe the first case of syringomyelia as an uncommon late complication of treated TBM in the setting of HIV infection. Early recognition of this rare entity may avoid irreversible neurological sequelae.

Diagnosis of tuberculous meningitis: clinical and laboratory parameters.

BACKGROUND: Confirming the clinical suspicion of tuberculous meningitis (TBM) has always been problematic. Whilst smear and culture positivity are diagnostic, these tests have low sensitivity. The polymerase chain reaction (PCR) assay has given variable results. AIM: This study attempted to improve the diagnostic yield by: (a) increasing the cerebrospinal fluid (CSF) volumes; (b) testing the yield from three specimens of CSF assumed to represent lumbar, cervico-thoracic cord, and base of brain CSF samples; (c) undertaking PCR assays using multiple primer sets; and (d) using real-time PCR. METHOD: Patients suspected of having cranial or spinal meningeal tuberculosis were entered into the study. Three aliquots of CSF were subjected to smear, culture, and conventional and real-time PCR. Three sets of primers - IS6110, MPB64, and PT8/9 - were used. Patients were retrospectively classified into four categories: 'definite TB' (culture positive), 'probable TB' (clinical and other tests suggestive of TB), 'not TB', and 'uncertain diagnosis'. RESULTS: A total of 68 patients were studied. There were 20 patients classified as definite TB, 24 probable TB, 17 not TB, and seven uncertain diagnosis. Forty-eight of 57 (84.2%) patients tested were HIV seropositive. The IS6110 PCR was positive in 27 patients which included 18/20 culture positive cases, six in the probable TB group, and three in the not TB group. The MPB64 and PT8/9 primers did not increase the yield. Real-time PCR was positive in seven additional patients. Combining the definite and probable TB, the sensitivity of all PCR assays was 70.5% (31/44) and specificity 87.5% (21/24). CONCLUSION: Targeting multiple sites of the TB genome using conventional PCR did not increase the number of positive cases. Real-time PCR was more sensitive. However, all the current techniques are still too insensitive to confidently exclude the diagnosis on laboratory grounds.

Primary and opportunistic pathogens associated with meningitis in adults in Bangui, Central African Republic, in relation to human immunodeficiency virus serostatus.

OBJECTIVE: To determine the causative organisms and characteristics of patients presenting with meningitis in Bangui in order to provide guidance to physicians for case management. METHODS: Adults with proven or suspected meningitis were enrolled in this prospective study. LABORATORY TESTS: Full blood count, blood chemistry, and HIV tests were performed. Cerebrospinal fluid (CSF) was submitted for routine microbiology, chemistry (glucose, protein), and hematology testing. When classical microbiology analyses were negative, a broad-range bacterial polymerase chain reaction (BRBPCR) was used. RESULTS AND CONCLUSIONS: Of the 276 patients enrolled, 215 (77.9%) were HIV positive. In HIV-positive patients cryptococcal meningitis (CM) was the most common cause of meningitis (39.1%) followed by pyogenic meningitis (PM) (30.7%), mononuclear meningitis (MM) (28.8%), and tuberculous meningitis (TM) (1.4%). In HIV-negative patients, PM was the most common cause (60.7%) followed by MM (37.7%) and CM (1.6%, one case). In-hospital mortality was higher in HIV-positive patients (73/128 = 57%) compared to those HIV negative (3/18 = 16.7%) (p = 0.001). Streptococcus pneumoniae (n = 26) was the most common bacterial diagnosis, mainly in HIV-positive patients (n = 22, 10.2%). Meningococcal meningitis (14 Neisseria meningitidis of group A and one W135) was diagnosed in nine (4.2%) HIV-positive and six (9.8%) HIV-negative patients. Gram-negative rods were isolated from five HIV-positive and two HIV-negative patients, respectively. The bacteria and fungi involved in meningitis did not display high levels of in vitro resistance. Conventional microbiology techniques failed to detect the causative agent in 55 (53.4%) PM cases. Broad-range bacterial PCR detected DNA from S. pneumoniae in three samples, N. meningitidis in two, Escherichia coli in one, Listeria monocytogenes in two and Staphylococcus aureus in one sample. In the CSF of five (three HIV negative and two HIV positive), PCR products were not identified with the oligonucleotide probes specific for the usual species of bacteria found in CSF, or genera commonly considered potential contaminants of clinical samples. Among the MM cases, 77 (90.5%) probable viral meningitis (54 HIV positive and 23 HIV negative) and eight TM (HIV positive) were suspected.

Clinical, cerebrospinal fluid and pathological findings and outcomes in HIV-positive and HIV-negative patients with tuberculous meningitis.

BACKGROUND: The early diagnosis of tuberculous (TB) meningitis remains difficult. In South Africa, the HIV epidemic has shifted the spectrum of meningitis towards chronic infections (mainly tuberculosis [TB] and cryptococcosis). This study aimed to analyze clinical, cerebrospinal fluid (CSF) and pathological findings and outcomes in TB meningitis to evaluate whether HIV infection significantly influences the characteristic findings. PATIENTS AND METHODS: 40 consecutive patients with TB meningitis presenting at the Pretoria Academic Hospital were evaluated clinically and chest X-rays (CXR), computerized tomography (CT) brain scans, CSF profiles, HIV and routine blood tests were analyzed. Postmortem examinations (PM) were performed in seven patients and outcomes were assessed after treatment. RESULTS: 20 patients were HIV-positive and 17 were negative (three not tested). History and clinical findings were similar in both groups. The mean Glasgow Coma Scale (GCS) value on admission was 13 in both groups, while CXR showed abnormalities consistent with TB in 9/17 with HIV and 7/15 without, with abnormal CT brain scans in 15/19 patients with HIV and 12/16 without. Dilated ventricles and infarcts occurred more commonly in HIV-positive patients. The CSF results showed similar results in both groups. PM in three HIV-positive patients showed weakly formed granulomas and extensive endarteritis and infarcts. Outcomes were similar in the two groups, but a low GCS value on admission was a better prognostic indicator than the CD4-count in HIV-positive patients. CONCLUSION: HIV infection does not significantly alter clinical and CSF findings in TB meningitis in South Africa, but ventricular dilatation and infarcts are more frequent in HIV-positive patients. The GCS gives a better indicator of prognosis than the CD4-count.

Dual infective pathology in patients with cryptococcal meningitis.

Coinfection of the nervous system by two distinct nonviral organisms is uncommon and often undiagnosed. Medical teaching emphasizes that a single pathologic process should be sought; however, in the presence of severe immunocompromise this approach may not hold true. We describe seven HIV-1 seropositive patients with cryptococcal meningitis, three of whom had a proven nervous system infection with a second organism: concurrent tuberculous meningitis, a tuberculoma, and the first documented case of cryptococcal meningitis and neurosyphilis.