Recurrence of Symptoms Following Cryptococcal Meningitis: Characterizing a Diagnostic Conundrum With Multiple Etiologies.

BACKGROUND: Cryptococcal meningitis is a common cause of AIDS-related mortality. Although symptom recurrence after initial treatment is common, the etiology is often difficult to decipher. We sought to summarize characteristics, etiologies, and outcomes among persons with second-episode symptomatic recurrence. METHODS: We prospectively enrolled Ugandans with cryptococcal meningitis and obtained patient characteristics, antiretroviral therapy (ART) and cryptococcosis histories, clinical outcomes, and cerebrospinal fluid (CSF) analysis results. We independently adjudicated cases of second-episode meningitis to categorize patients as (1) microbiological relapse, (2) paradoxical immune reconstitution inflammatory syndrome (IRIS), (3) persistent elevated intracranial pressure (ICP) only, or (4) persistent symptoms only, along with controls of primary cryptococcal meningitis. We compared groups with chi-square or Kruskal-Wallis tests as appropriate. RESULTS: 724 participants were included (n = 607 primary episode, 81 relapse, 28 paradoxical IRIS, 2 persistently elevated ICP, 6 persistent symptoms). Participants with culture-positive relapse had lower CD4 (25 cells/µL; IQR: 9-76) and lower CSF white blood cell (WBC; 4 cells/µL; IQR: 4-85) counts than paradoxical IRIS (CD4: 78 cells/µL; IQR: 47-142; WBC: 45 cells/µL; IQR: 8-128). Among those with CSF WBC <5 cells/µL, 86% (43/50) had relapse. Among those with CD4 counts <50 cells/µL, 91% (39/43) had relapse. Eighteen-week mortality (from current symptom onset) was 47% among first episodes of cryptococcal meningitis, 31% in culture-positive relapses, and 14% in paradoxical IRIS. CONCLUSIONS: Poor immune reconstitution was noted more often in relapse than IRIS as evidenced by lower CSF WBC and blood CD4 counts. These easily obtained laboratory values should prompt initiation of antifungal treatment while awaiting culture results. CLINICAL TRIALS REGISTRATION: NCT01802385.

Fujifilm SILVAMP TB LAM Assay on Cerebrospinal Fluid for the Detection of Tuberculous Meningitis in Adults With Human Immunodeficiency Virus.

BACKGROUND: Tuberculous meningitis (TBM) has a high fatality rate, with inadequate diagnostic tests being a major contributor. The rollout of Xpert MTB/Rif and Xpert MTB/RIF Ultra (Xpert Ultra) have improved time-to-diagnosis with sensitivities similar to culture, yet test availability and sensitivity are inadequate. The TB lipoarabinomannan lateral flow assay (AlereLAM) offers ease of use, but its low sensitivity in cerebrospinal fluid (CSF) limits clinical utility for TBM. The Fujifilm SILVAMP TB LAM (FujiLAM) assay has excellent sensitivity in urine, but performance on cerebrospinal fluid is uncertain. METHODS: We conducted a prospective cohort study at Kiruddu National Referral Hospital in Kampala, Uganda, enrolling patients suspected to have TBM. CSF was tested using AlereLAM, Xpert Ultra, culture, and FujiLAM. Results were compared with 2 reference standards: probable and definite TBM or definite TBM alone by the uniform TBM case definition. RESULTS: Of 101 patients enrolled (95/101 HIV-positive), 34 had definite TBM and 24 had probable TBM. FujiLAM sensitivity on CSF was 52% (30/58) for definite or probable TBM compared with 55% (32/58) for Xpert Ultra. AlereLAM had lower sensitivity than FujiLAM in the subgroup of patients tested with both assays (14% [4/28] vs 50% [14/28]; P < .01). FujiLAM specificity was 98% (42/43) for patients without probable or definite TBM. CONCLUSIONS: FujiLAM showed higher sensitivity than AlereLAM, with sensitivity potentially approaching that of Xpert Ultra. FujiLAM could improve time-to-treatment-initiation, especially in settings where the more technical Xpert Ultra system might not be feasible. Large confirmatory studies are needed.

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.

Caregiver "objective attitude" toward patients with neurodegenerative disease: Consequences for caregiver strain and relationship closeness.

Many caregivers of patients with neurodegenerative disease experience physical and psychological strain, which is associated with negative health outcomes. Caregiver strain may be partly attributable to negative emotional responses (e.g.of resentment) to the behavioral, cognitive, and physical changes associated with patients' disease. The philosopher Peter Strawson observed that in dealing with people who have neurological impairments, we often choose to suspend such emotional responses, adopting what he labeled the "objective attitude," though this may come at the expense of our relationships with them. In this study, we assessed the mediating effect of caregivers' adoption of the objective attitude on caregiver strain and relationship closeness in the setting of disease progression. Caregivers of patients with neurodegenerative disorders (n = 215) completed the Clinical Dementia Rating, Relationship-Closeness scale, Caregiver Strain Index, and a novel questionnaire assessing the adoption of the objective attitude. A structural equation model assessing associations among these variables demonstrated good fit (χ2 (88)=164.621, p < 0.001; CFI = 0.929, RMSEA = 0.064.) and showed that adoption of the objective attitude mediated the association between disease progression and relationship closeness (total ß= -0.233, 95% CI: -0.351, -0.113; indirect ß= -0.483, 95% CI: -0.602, -0.364; direct ß = 0.250, 95% CI: 0.117, 0.384), but did not mediate the association between disease progression and caregiver strain (total ß = 0.323, 95% CI: 0.234, 0.412; indirect ß = 0.089, 95% CI: -0.027, 0.206; direct ß = 0.153, 95% CI: -0.043, 0.349). For future work, we propose longitudinal measurements of these constructs to test the directionality of associations and consideration of how models for caregiver support can draw upon interdisciplinary insights.

Photoactivatable genetically encoded calcium indicators for targeted neuronal imaging.

Circuit mapping requires knowledge of both structural and functional connectivity between cells. Although optical tools have been made to assess either the morphology and projections of neurons or their activity and functional connections, few probes integrate this information. We have generated a family of photoactivatable genetically encoded Ca(2+) indicators that combines attributes of high-contrast photolabeling with high-sensitivity Ca(2+) detection in a single-color protein sensor. We demonstrated in cultured neurons and in fruit fly and zebrafish larvae how single cells could be selected out of dense populations for visualization of morphology and high signal-to-noise measurements of activity, synaptic transmission and connectivity. Our design strategy is transferrable to other sensors based on circularly permutated GFP (cpGFP).

Variability in Pediatric Ideal Body Weight Calculation: Implications for Lung-Protective Mechanical Ventilation Strategies in Pediatric Acute Respiratory Distress Syndrome.

OBJECTIVES: No gold standard for ideal body weight determination in children exists. We aimed to compare four methods of ideal body weight calculation and determine level of agreement between methods and impact of measurement variance on tidal volumes prescribed in mechanically ventilated pediatric acute respiratory distress syndrome. DESIGN: Post hoc analysis of four multicenter pediatric acute respiratory distress syndrome studies. SETTING: Twenty-six academic PICUs. PATIENTS: Five hundred eighty-nine patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Ideal body weight was calculated by four common methods: National Center for Health Statistics, McLaren, Moore, and body mass index, and compared in three ways: 1) determine the proportion of the cohort for which each method could successfully calculate ideal body weight; 2) compare the level of agreement between the ideal body weight methods by Bland-Altman analysis; and 3) evaluate the difference in tidal volume when 6 mL/kg ideal body weight was prescribed. We a priori defined the better method to be one that could calculate ideal body weight in most subjects, had good agreement with other methods, and led to a lower tidal volume. Only 55% could have ideal body weight measured by all four methods. National Center for Health Statistics, McLaren, and Moore methods could calculate ideal body weight in greater than or equal to 90%, whereas body mass index method was successful in only 61% because of no body mass index validation in less than 2-year-olds. In comparing each method to the others, there was great variance, particularly in greater than or equal to 10-year-olds. This variance was greatest between Moore and body mass index methods with greater than or equal to 10 kg difference in ideal body weight in some subjects. The McLaren method had the best agreement with all other methods, and yielded similar prescribed tidal volume in 2- to 10-year-olds and lower tidal volume in greater than or equal to 10 years old. CONCLUSIONS: There is substantial variation in calculated ideal body weight among four commonly used methods, particularly in adolescents. Since varying ideal body weight may lead to discrepancies in pediatric acute respiratory distress syndrome care, a standard approach to ideal body weight measurement is needed. We recommend the McLaren method to calculate ideal body weight in children with pediatric acute respiratory distress syndrome until a gold standard method is validated.

Poor Adherence to Lung-Protective Mechanical Ventilation in Pediatric Acute Respiratory Distress Syndrome.

OBJECTIVES: To determine the frequency of low-tidal volume ventilation in pediatric acute respiratory distress syndrome and assess if any demographic or clinical factors improve low-tidal volume ventilation adherence. DESIGN: Descriptive post hoc analysis of four multicenter pediatric acute respiratory distress syndrome studies. SETTING: Twenty-six academic PICU. PATIENTS: Three hundred fifteen pediatric acute respiratory distress syndrome patients. MEASUREMENTS AND MAIN RESULTS: All patients who received conventional mechanical ventilation at hours 0 and 24 of pediatric acute respiratory distress syndrome who had data to calculate ideal body weight were included. Two cutoff points for low-tidal volume ventilation were assessed: less than or equal to 6.5 mL/kg of ideal body weight and less than or equal to 8 mL/kg of ideal body weight. Of 555 patients, we excluded 240 for other respiratory support modes or missing data. The remaining 315 patients had a median PaO2-to-FIO2 ratio of 140 (interquartile range, 90-201), and there were no differences in demographics between those who did and did not receive low-tidal volume ventilation. With tidal volume cutoff of less than or equal to 6.5 mL/kg of ideal body weight, the adherence rate was 32% at hour 0 and 33% at hour 24. A low-tidal volume ventilation cutoff of tidal volume less than or equal to 8 mL/kg of ideal body weight resulted in an adherence rate of 58% at hour 0 and 60% at hour 24. Low-tidal volume ventilation use was no different by severity of pediatric acute respiratory distress syndrome nor did adherence improve over time. At hour 0, overweight children were less likely to receive low-tidal volume ventilation less than or equal to 6.5 mL/kg ideal body weight (11% overweight vs 38% nonoverweight; p = 0.02); no difference was noted by hour 24. Furthermore, in the overweight group, using admission weight instead of ideal body weight resulted in misclassification of up to 14% of patients as receiving low-tidal volume ventilation when they actually were not. CONCLUSIONS: Low-tidal volume ventilation is underused in the first 24 hours of pediatric acute respiratory distress syndrome. Age, Pediatric Risk of Mortality-III, and pediatric acute respiratory distress syndrome severity were not associated with improved low-tidal volume ventilation adherence nor did adherence improve over time. Overweight children were less likely to receive low-tidal volume ventilation strategies in the first day of illness.

Neurocognitive outcomes of tuberculous meningitis in a primarily HIV-positive Ugandan cohort.

Background: The toll of tuberculous meningitis (TBM) in both mortality and disability is considerable, but advancements in rehabilitation have the potential to improve the functional abilities and the quality of survivors' lives. However, the typical phenotype of neurocognitive impairment in TBM survivors remains unstudied in HIV-predominant populations in sub-Saharan Africa. Methods: We tested 36 survivors of TBM in Uganda with a comprehensive battery of neurocognitive assessments at 8 and 24 weeks after diagnosis, and compared results to a representative cohort of HIV-uninfected Ugandans. Results: While participants had a broad range of impairments at eight weeks, there was marked improvement by 24 weeks, when a phenotype of impairment including deficits in motor functioning, verbal learning and memory, processing speed, and executive function emerged. These deficits were present despite good clinician-rated functional status. The majority (23/27, 85%) had evidence of moderate to severe depression at week 8, and at week 24 (18/24, 75%). Conclusion: These findings highlight the need for more comprehensive neurocognitive assessment in the survivors of TBM, and further investment in and study of rehabilitation, including management of depression, to improve long-term outcomes in this population.

Tuberculosis IRIS: Pathogenesis, Presentation, and Management across the Spectrum of Disease.

Antiretroviral therapy (ART), while essential in combatting tuberculosis (TB) and HIV coinfection, is often complicated by the TB-associated immune reconstitution inflammatory syndrome (TB-IRIS). Depending on the TB disease site and treatment status at ART initiation, this immune-mediated worsening of TB pathology can take the form of paradoxical TB-IRIS, unmasking TB-IRIS, or CNS TB-IRIS. Each form of TB-IRIS has unique implications for diagnosis and treatment. Recently published studies have emphasized the importance of neutrophils and T cell subtypes in TB-IRIS pathogenesis, alongside the recognized role of CD4 T cells and macrophages. Research has also refined our prognostic understanding, revealing how the disease can impact lung function. While corticosteroids remain the only trial-supported therapy for prevention and management of TB-IRIS, increasing interest has been given to biologic therapies directly targeting the immune pathology. TB-IRIS, especially its unmasking form, remains incompletely described and more data is needed to validate biomarkers for diagnosis. Management strategies remain suboptimal, especially in the highly morbid central nervous system (CNS) form of the disease, and further trials are necessary to refine treatment. In this review we will summarize the current understanding of the immunopathogenesis, the presentation of TB-IRIS and the evidence for management recommendations.

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.