High-Dose Oral and Intravenous Rifampicin for the Treatment of Tuberculous Meningitis in Predominantly Human Immunodeficiency Virus (HIV)-Positive Ugandan Adults: A Phase II Open-Label Randomized Controlled Trial

BACKGROUND

High-dose rifampicin may improve outcomes of tuberculous meningitis (TBM). Little safety or pharmacokinetic (PK) data exist on high-dose rifampicin in human immunodeficiency virus (HIV) coinfection, and no cerebrospinal fluid (CSF) PK data exist from Africa. We hypothesized that high-dose rifampicin would increase serum and CSF concentrations without excess toxicity.

METHODS

In this phase II open-label trial, Ugandan adults with suspected TBM were randomized to standard-of-care control (PO-10, rifampicin 10 mg/kg/day), intravenous rifampicin (IV-20, 20 mg/kg/day), or high-dose oral rifampicin (PO-35, 35 mg/kg/day). We performed PK sampling on days 2 and 14. The primary outcomes were total exposure (AUC0-24), maximum concentration (Cmax), CSF concentration, and grade 3-5 adverse events.

RESULTS

We enrolled 61 adults, 92% were living with HIV, median CD4 count was 50 cells/µL (interquartile range [IQR] 46-56). On day 2, geometric mean plasma AUC0-24hr was 42.9·h mg/L with standard-of-care 10 mg/kg dosing, 249·h mg/L for IV-20 and 327·h mg/L for PO-35 (P < .001). In CSF, standard of care achieved undetectable rifampicin concentration in 56% of participants and geometric mean AUC0-24hr 0.27 mg/L, compared with 1.74 mg/L (95% confidence interval [CI] 1.2-2.5) for IV-20 and 2.17 mg/L (1.6-2.9) for PO-35 regimens (P < .001). Achieving CSF concentrations above rifampicin minimal inhibitory concentration (MIC) occurred in 11% (2/18) of standard-of-care, 93% (14/15) of IV-20, and 95% (18/19) of PO-35 participants. Higher serum and CSF levels were sustained at day 14. Adverse events did not differ by dose (P = .34).

CONCLUSIONS

Current international guidelines result in sub-therapeutic CSF rifampicin concentration for 89% of Ugandan TBM patients. High-dose intravenous and oral rifampicin were safe and respectively resulted in exposures ~6- and ~8-fold higher than standard of care, and CSF levels above the MIC.

Standardized Urine-Based Tuberculosis (TB) Screening With TB-Lipoarabinomannan and Xpert MTB/RIF Ultra in Ugandan Adults With Advanced Human Immunodeficiency Virus Disease and Suspected Meningitis

BACKGROUND

Diagnosis of extrapulmonary tuberculosis (TB) remains challenging. We sought to determine the prevalence of disseminated TB by testing urine with TB-lipoarabinomannan (TB-LAM) lateral flow assay and Xpert MTB/RIF Ultra (Ultra) in hospitalized adults.

METHODS

We prospectively enrolled human immunodeficiency virus (HIV)-positive adults with suspected meningitis in Uganda during 2018-2020. Participants underwent standardized urine-based TB screening. Urine (60 mcL) was tested with TB-LAM (Alere), and remaining urine was centrifuged with the cell pellet resuspended in 2 mL of urine for Xpert Ultra testing.

RESULTS

We enrolled 348 HIV-positive inpatients with median CD4 of 37 cells/mcL (interquartile range, 13-102 cells/mcL). Overall, 26% (90 of 348; 95% confidence interval [CI], 21%-30%) had evidence of disseminated TB by either urine assay. Of 243 participants with both urine TB-LAM and Ultra results, 20% (48 of 243) were TB-LAM-positive, 12% (29 of 243) were Ultra-positive, and 6% (14 of 243) were positive by both assays. In definite and probable TB meningitis, 37% (14 of 38) were TB-LAM-positive and 41% (15 of 37) were Ultra-positive. In cryptococcal meningitis, 22% (40 of 183) were TB-LAM-positive and 4.4% (6 of 135) were Ultra-positive. Mortality trended higher in those with evidence of disseminated TB by either assay (odds ratio = 1.44; 95% CI, 0.83-2.49; P = .19) and was 6-fold higher in those with definite TB meningitis who were urine Ultra-positive (odds ratio = 5.67; 95% CI, 1.13-28.5; P = .04).

CONCLUSIONS

In hospitalized Ugandans with advanced HIV disease and suspected meningitis, systematic screening with urine TB-LAM and Ultra found a high prevalence of urine TB test positivity (26%). In those with TB meningitis, urine tests were positive in over one third. There was little concordance between Ultra and TB-LAM, which warrants further investigation.

Xpert MTB/RIF Ultra for the diagnosis of HIV-associated tuberculous meningitis: a prospective validation study

INTRODUCTION

Tuberculous meningitis accounts for 1-5% of tuberculosis cases. Diagnostic delay contributes to poor outcomes. We evaluated the performance of the new Xpert MTB/RIF Ultra (Xpert Ultra) for tuberculous meningitis diagnosis.

METHODS

In this prospective validation study, we tested the cerebrospinal fluid (CSF) of adults presenting with suspected meningitis (ie, headache or altered mental status with clinical signs of meningism) to the Mulago National Referral Hospital and Mbarara Regional Referral Hospital in Uganda. We centrifuged the CSF, resuspended the cell pellet in 2 mL CSF, and tested 0·5 mL aliquots with Xpert Ultra, Xpert MTB/RIF (Xpert), and mycobacterial growth indicator tube (MGIT) culture. We quantified diagnostic performance against the uniform case definition of probable or definite tuberculous meningitis and a composite microbiological reference standard.

FINDINGS

From Nov 25, 2016, to Jan 24, 2019, we screened 466 adults with suspected meningitis and tested 204 for tuberculous meningitis. Uniform clinical case definition classified 51 participants as having probable or definite tuberculous meningitis. Against this uniform case definition, Xpert Ultra had 76·5% sensitivity (95% CI 62·5-87·2; 39 of 51 patients) and a negative predictive value of 92·7% (87·6-96·2; 153 of 165), compared with 55·6% sensitivity (44·0-70·4; 25 of 45; p=0·0010) and a negative predictive value of 85·8% (78·9-91·1; 121 of 141) for Xpert and 61·4% sensitivity (45·5-75·6; 27 of 44; p=0·020) and negative predictive value of 85·2% (77·4-91·1; 98 of 115) for MGIT culture. Against the composite microbiological reference standard, Xpert Ultra had sensitivity of 92·9% (80·5-98·5; 39 of 42), higher than Xpert at 65·8% (48·6-80·4; 25 of 38; p=0·0063) and MGIT culture at 72·2% (55·9-86·2; 27 of 37; p=0·092). Xpert Ultra detected nine tuberculous meningitis cases missed by Xpert and MGIT culture.

INTERPRETATION

Xpert Ultra detected tuberculous meningitis with higher sensitivity than Xpert and MGIT culture in this HIV-positive population. However, with a negative predictive value of 93%, Xpert Ultra cannot be used as a rule-out test. Clinical judgment and novel highly sensitive point-of-care tests are still required.

FUNDING

Wellcome Trust, National Institute of Health, National Institute of Neurologic Diseases and Stroke, Fogarty International Center, and National Institute of Allergy and Infectious Diseases.

Poverty and eosinophilia are risk factors for endomyocardial fibrosis (EMF) in Uganda

OBJECTIVE

To determine the relative risks of socio-demographic, dietary, and environmental factors for endomyocardial fibrosis (EMF) in Uganda.

METHOD

Unmatched case control study in Mulago Hospital, Kampala. Cases (n = 61) were sequential patients hospitalized with an echocardiographic diagnosis of EMF from June 1995 to March 1996. Controls (n = 120) were concurrent patients with other forms of heart disease (heart controls, n = 59) and subjects admitted for trauma or elective surgery (hospital controls, n = 61). All consenting subjects answered a structured questionnaire administered by trained interviewers. Complete blood counts, malaria films and stool examination for ova and parasites were performed. Questionnaires elicited information on home address, economic circumstances, variables concerned with environmental exposures and usual diet before becoming ill.

RESULTS

After adjustment for age and sex, cases were significantly more likely than controls to have Rwanda/Burundi ethnic origins (P = 0.008). Compared with controls, cases had a lower level of education (P < 0.001 for heart controls and P = 0.07 for hospital controls), were more likely to be peasants (P < 0.001), and to come from Luwero or Mukono Districts (P = 0.003). After further adjustment for peasant occupation, cases were more likely than controls to walk barefoot (P = 0.015), consume cassava as their staple food (P < 0.001) and to lack fish or meat in dietary sauces (P = 0.02). Cases were more likely to exhibit absolute eosinophilia (P = 0.006). The effect of cassava diet was more marked in the younger age group, while the effect of eosinophilia was greater in adults. Socio-economic disadvantage is a risk for EMF. Absolute eosinophilia is a putative cause of EMF, a finding not explained by parasitism.

CONCLUSION

Data indicate that relative poverty and environmental factors triggering eosinophilia appear to act in a geographically restricted region of Uganda in the aetiology of EMF.

Echocardiographic diagnosis of heart disease in Uganda

Five hundred consecutive cardiological patients were reviewed and evaluated by echocardiography in Mulago Hospital as a referral service. All diagnostic problems in cardiology in the hospital and to a certain degree from other institutions were reviewed. The commonest diagnosis was endomyocardial fibrosis (EMF) 19.8%, followed by congenital heart disease (CHD) 15% and rheumatic heart disease (RHD) 11%. The anatomical distribution of fibrotic lesions in EMF (left, right or biventricular) correlated with that found in previous autopsy series from Mulago Hospital thus demonstrating the accuracy of echocardiography. We were able to quantify the contribution of echocardiography to a correct diagnosis which varied between 13% in RHD to 90% in mitral valve prolapse (MVP). Echocardiography was able to confirm the clinical diagnosis of subacute bacterial endocarditis (SBE) in 69% of cases. The obtained data suggests that EMF may be the most common heart disease in Uganda contrary to the pattern of heart disease outlined in earlier works. The favourable cost/benefit ratio of echocardiography (i.e. its easy availability and maintenance), as well as the absence of consumable materials in comparison to other cardiac diagnostic tools such as catheterization, chest X-ray and ECG is emphasized, together with the multipurpose use of the machine.