Antibody-mediated cellular responses are dysregulated in Multisystem Inflammatory Syndrome in Children (MIS-C)

Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe complication of SARS-CoV-2 infection characterized by multi-organ involvement and inflammation. Testing of cellular function ex vivo to understand the aberrant immune response in MIS-C is limited. Despite strong antibody production in MIS-C, SARS-CoV-2 nucleic acid testing can remain positive for 4-6 weeks after infection. Therefore, we hypothesized that dysfunctional cell-mediated antibody responses downstream of antibody production may be responsible for delayed clearance of viral products in MIS-C. In MIS-C, monocytes were hyperfunctional for phagocytosis and cytokine production, while natural killer (NK) cells were hypofunctional for both killing and cytokine production. The decreased NK cell cytotoxicity correlated with an NK exhaustion marker signature and systemic IL-6 levels. Potentially providing a therapeutic option, cellular engagers of CD16 and SARS-CoV-2 proteins were found to rescue NK cell function in vitro. Together, our results reveal dysregulation in antibody-mediated cellular responses unique to MIS-C that likely contribute to the immune pathology of this disease.

2058. Effect of Covid-19 lockdowns on identification of advanced HIV disease in outpatient clinics in Uganda

Background

Despite HIV test and treat initiatives, the World Health Organization (WHO) estimates that 25% to 40% of persons living with HIV (PLWH) have advanced HIV disease (CD4< 200 cells/mcL). The objective of this study is to understand how the Covid-19 pandemic affected identification of persons with advanced HIV disease in Ugandan HIV clinics.

Methods

We retrospectively reviewed data from 67 HIV clinics surrounding Kampala, Uganda. As part of routine data collection for PEPFAR reporting, number of persons entering care by clinic and number of persons presenting with CD4< 200 cells/mcL were summarized by month between July 2019 and January 2022. We used the Johns Hopkins Coronavirus Resource Center website to summarize Ugandan Covid-19 cases by month. Covid-19 lockdown dates were taken from the Ugandan government’s COVID-19 information website. Specifically, between March and May 2020, there was a period of strict lockdown where public transportation was halted. Between May and July 2020 there was a less stringent lockdown (public transportation was available, but schools and many businesses remained closed). Again between June and July 2021 a strict lockdown occurred.

Results

Prior to the Covid-19 pandemic, between July 2019 and February 2020, an average of 16% (265/1675) of PLWH presented monthly with advanced HIV disease. During Covid-19 lockdowns from March 2020 to July 2020, only 9% (102/1124) of PLWH presented with advanced HIV disease. During the period of lockdown, there was a 33% reduction in the monthly average number of PLWH presenting to HIV clinics, and a 62% reduction in the monthly average number of PLWH presenting with advanced HIV disease. From February 2021 to January 2022, 18% (185/987) of PLWH presented with advanced HIV disease. During this period, there was a 42% reduction in the number of persons presenting to HIV care; of those who presented, a larger portion presented with advanced HIV disease.

Conclusion

The Covid-19 lockdowns negatively affected presentation of PLWH to care, most significantly among persons with advanced HIV disease. This reduction in presentation to care has persisted and not recovered to pre-Covid levels. In the past year, 18% of PLWH presented with advanced HIV disease.

Disclosures

All Authors: No reported disclosures.

869. Oral Encochleated Amphotericin B for Cryptococcal Meningitis: a Phase II Randomized Trial

Background

Intravenous (IV) amphotericin B is the gold standard treatment of severe mycoses. A new orally absorbed, less-toxic formulation of amphotericin has been developed (Matinas Biopharma). We evaluated the efficacy of this novel anti-fungal agent amongst adults with cryptococcal meningitis.

Methods

We conducted a phase II randomized clinical trial testing oral encochleated amphotericin B (cAMB) versus IV amphotericin B for first episode cryptococcal meningitis in Kampala, Uganda from December 2020 to August 2021. Participants were HIV-positive, CSF cryptococcal antigen (CrAg) positive, and had the capacity to consent and take oral medications (GCS=15). Participants in the experimental arm received two loading doses of either IV deoxycholate amphotericin B 1.0 mg/kg/day or liposomal amphotericin 3 mg/kg/day, followed by 1.8g oral cAMB daily in 6 divided doses through 2 weeks with flucytosine (5FC) at 100mg/kg/day, and thereafter cAMB at 1.2g daily in 4 divided doses through 6 weeks. Participants in the control arm received 7 days of IV amphotericin B (deoxycholate or liposomal) with 5FC, then 7 days of fluconazole 1200mg/day. After 14 days, all participants received fluconazole 800mg/day through 10 weeks and thereafter a maintenance dose of 200mg/day.

Results

We randomized 40 participants to oral cAMB + 5FC and 30 control participants to IV amphotericin + 5FC. With cAMB the 30-day survival was 97.5% (39/40) and 18-week survival was 90% (36/40) compared with 87% (26/30) 18-week survival in IV amphotericin controls.

The CSF Early Fungicidal Activity (EFA) was lower with oral cAMB (mean EFA = 0.42 log₁₀Cryptococcus CFU/mL/day; 95%CI, 0.29 to 0.54) versus IV amphotericin (mean EFA = 0.52 log₁₀ CFU/mL/day; 95%CI, 0.39 to 0.66). Among those CSF culture positive at baseline, CSF sterility was achieved by 2 weeks in 65% (24/37) of cAMB participants and 68% (17/25) of controls.

Grade >=3 laboratory adverse events were more common with IV amphotericin. Grade 3–4 anaemia occurred in 10% (n=4) with cAMB versus 37% (n=11) with IV amphotericin. Grade 3 hypokalaemia (< 3mEq/L) occurred in 5% (n=2) with cAMB versus 27% (n=8) with IV amphotericin.

Conclusion

Novel oral cAMB appears to be a safe agent with promising efficacy for HIV-related cryptococcal meningitis.

Disclosures

All Authors: No reported disclosures.

Clostridium Tetani Bacteremia From a Suspected Cutaneous Source

Bacteremia is a rare complication of Clostridium tetani infection. To our knowledge, there are only two case reports to date of C. tetani bacteremia, both hypothesized to be secondary to a gastrointestinal source. Herein, we report a case of an elderly man with genome sequence-proven C. tetani bacteremia from a possible cutaneous source without neuromuscular symptoms.

Cytomegalovirus Viremia Associated With Increased Mortality in Cryptococcal Meningitis in Sub-Saharan Africa

BACKGROUND

Cryptococcal meningitis and tuberculosis are both important causes of death in persons with advanced human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Cytomegalovirus (CMV) viremia may be associated with increased mortality in persons living with HIV who have tuberculosis. It is unknown whether concurrent CMV viremia is associated with mortality in other AIDS-related opportunistic infections.

METHODS

We prospectively enrolled Ugandans living with HIV who had cryptococcal meningitis from 2010-2012. Subsequently, we analyzed stored baseline plasma samples from 111 subjects for CMV DNA. We compared 10-week survival rates among those with and without CMV viremia.

RESULTS

Of 111 participants, 52% (58/111) had detectable CMV DNA (median plasma viral load 498 IU/mL, interquartile range [IQR] 259-2390). All samples tested were positive on immunoglobin G serology. The median CD4+ T cell count was 19 cells/µL (IQR 9-70) and did not differ by the presence of CMV viremia (P = .47). The 10-week mortality rates were 40% (23/58) in those with CMV viremia and 21% (11/53) in those without CMV viremia (hazard ratio 2.19, 95% confidence interval [CI] 1.07-4.49; P = .03), which remained significant after a multivariate adjustment for known risk factors of mortality (adjusted hazard ratio 3.25, 95% CI 1.49-7.10; P = .003). Serum and cerebrospinal fluid cytokine levels were generally similar and cryptococcal antigen-specific immune stimulation responses did not differ between groups.

CONCLUSIONS

Half of persons with advanced AIDS and cryptococcal meningitis had detectable CMV viremia. CMV viremia was associated with an over 2-fold higher mortality rate. It remains unclear whether CMV viremia in severely immunocompromised persons with cryptococcal meningitis contributes directly to this mortality or may reflect an underlying immune dysfunction (ie, cause vs effect).

CLINICAL TRIALS REGISTRATION

NCT01075152.

Cryptococcosis in pregnancy and the postpartum period: Case series and systematic review with recommendations for management

Cryptococcal meningitis causes 15% of AIDS-related deaths. Optimal management and clinical outcomes of pregnant women with cryptococcosis are limited to case reports, as pregnant women are often excluded from research. Amongst pregnant women with asymptomatic cryptococcosis, no treatment guidelines exist. We prospectively identified HIV-infected women who were pregnant or recently pregnant with cryptococcosis, screened during a series of meningitis research studies in Uganda from 2012 to 2018. Among 571 women screened for cryptococcosis, 13 were pregnant, one was breastfeeding, three were within 14 days postpartum, and two had recently miscarried. Of these 19 women (3.3%), 12 had cryptococcal meningitis, six had cryptococcal antigenemia, and one had a history of cryptococcal meningitis and was receiving secondary prophylaxis. All women with meningitis received amphotericin B deoxycholate (0.7-1.0 mg/kg). Five were exposed to 200-800 mg fluconazole during pregnancy. Of these five, three delivered healthy babies with no gross physical abnormalities at birth, one succumbed to meningitis, and one outcome was unknown. Maternal meningitis survival rate at hospital discharge was 75% (9/12), and neonatal/fetal survival rate was 44% (4/9) for those mothers who survived. Miscarriages and stillbirths were common (n = 4). Of six women with cryptococcal antigenemia, two received fluconazole, one received weekly amphotericin B, and three had unknown treatment courses. All women with antigenemia survived, and none developed clinical meningitis. We report good maternal outcomes but poor fetal outcomes for cryptococcal meningitis using amphotericin B, without fluconazole in the first trimester, and weekly amphotericin B in place of fluconazole for cryptococcal antigenemia.

Bacteremia and central line infection caused by Bosea thiooxidans

We describe a case of central venous catheter infection and bacteremia caused by Bosea thiooxidans, which has not been previously described in the literature. Bosea spp. is a gram-negative bacterium that has been isolated from hospital water supplies and may become an important cause of nosocomial infections.

2120. Minimum Inhibitory Concentration Distribution of Fluconazole against Cryptococcus Species and the Fluconazole Exposure Prediction Model

Background

Fluconazole is lifesaving for the treatment and prevention of cryptococcosis; however, optimal dosing is unknown. Initial fluconazole doses of 100 mg to 2000 mg/day have been used. Prevalence of fluconazole non-susceptible Cryptococcus is increasing over time, risking the efficacy of long-established standard dosing. Based on current minimum inhibitory concentration (MIC) distribution, we modeled fluconazole concentration and area under the curve (AUC) relative to MIC to propose a rational fluconazole dosing strategy.

Methods

First, we conducted a systematic review using the MEDLINE database for reports of fluconazole MIC distribution against clinical Cryptococcus isolates. Second, we utilized fluconazole concentrations from 92 Ugandans who received fluconazole 800 mg/day coupled with fluconazole’s known pharmacokinetics to predict plasma fluconazole concentrations for doses ranging from 100 mg to 2000 mg via linear regression. Third, the fluconazole AUC above MIC ratio were calculated using Monte Carlo simulation and using the MIC distribution elucidated during the systemic review.

Results

We summarized 21 studies with 11,094 clinical Cryptococcus isolates. MICs were normally distributed with geometric mean of 3.4 mg/mL, median (MIC₅₀) of 4 mg/mL, and 90th percentile (MIC₉₀) of 16 mg/mL. The median MIC₅₀ trended upwards from 4 mg/mL in 2000–2012 to 8 mg/mL in 2014–2018. Predicted sub-therapeutic fluconazole concentrations (below MIC) would occur in 38% with 100 mg, 20% with 200 mg, and 8% with 400 mg. AUC/MIC ratio > 100 would occur in 53% for 400 mg, 74% for 800 mg, 84% for 1200 mg, and 88% for 1,600 mg.

Conclusion

Currently recommended fluconazole doses may be inadequate for cryptococcosis. Further clinical studies are needed for rational fluconazole dose selection.

Disclosures

All authors: No reported disclosures.

1716. Baseline Serum C-Reactive Protein Level Predicts Mortality in Cryptococcal Meningitis

Background

C-reactive protein (CRP) is an acute-phase protein produced by the liver in response to systemic inflammation. CRP is a helpful surrogate biomarker widely used in various infections, particularly for following the progression and resolution of infection. We aimed to determine the association between baseline CRP level and cryptococcal meningitis outcome.

Methods

We reviewed 168 prospectively enrolled HIV-infected Ugandans with confirmed first-episode cryptococcal meningitis. Baseline serum samples collected within 5 days from diagnosis had CRP levels measured and categorized into quartiles. We compared baseline serum CRP with 18-week survival using unadjusted time-to-event analysis.

Results

Of 168 participants, the first quartile of baseline serum CRP was 83.6 mg/L. Baseline CD4 count, HIV viral load, and cerebrospinal fluid results did not differ by quartile. Participants with CRP > 49.5 mg/L more likely presented with Glasgow Coma Scale <15 (P = 0.03). The 18-week mortality rate was 54.8% (46/84) in the highest two quartile CRP groups (49.5 mg/L), 40.5% (17/42) in the mid-range CRP group (29–49.5 mg/L), and 14.3% (6/42) in the low CRP group (<29 mg/L) (P < 0.001) (Figure 1).

Conclusion

Higher baseline serum CRP is associated with increased mortality in HIV-infected individuals with first-episode cryptococcal meningitis. The serum CRP could be a surrogate marker for undiagnosed co-infections or may reflect immune dysregulation leading to worse outcomes in persons with advanced AIDS and concomitant cryptococcal meningitis. Additional studies investigating more specific inflammatory biomarkers and the longitudinal trend in CRP with effective therapy would be informative.

Disclosures

All authors: No reported disclosures.

Minimum Inhibitory Concentration Distribution of Fluconazole against Cryptococcus Species and the Fluconazole Exposure Prediction Model

BACKGROUND

Fluconazole is lifesaving for treatment and prevention of cryptococcosis; however, optimal dosing is unknown. Initial fluconazole doses of 100mg to 2000mg/day have been used. Prevalence of fluconazole non-susceptible Cryptococcus is increasing over time, risking the efficacy of long-established standard dosing. Based on current minimum inhibitory concentration (MIC) distribution, we modeled fluconazole concentration and area under the curve (AUC) relative to MIC to propose a rational fluconazole dosing strategy.

METHODS

First, we conducted a systematic review using MEDLINE database for reports of fluconazole MIC distribution against clinical Cryptococcus isolates. Second, we utilized fluconazole concentrations from 92 Ugandans who received fluconazole 800mg/day coupled with fluconazole's known pharmacokinetics to predict plasma fluconazole concentrations for doses ranging from 100mg to 2000mg via linear regression. Third, the fluconazole AUC above MIC ratio were calculated using Monte Carlo simulation and using the MIC distribution elucidated during the systemic review.

RESULTS

We summarized 21 studies with 11,049 clinical Cryptococcus isolates. MICs were normally distributed with geometric mean of 3.4 μg/mL, median (MIC50) of 4 μg/mL, and 90th percentile (MIC90) of 16 μg/mL. The median MIC50 trended upwards from 4 μg/mL in 2000-2012 to 8 μg/mL in 2014-2018. Predicted sub-therapeutic fluconazole concentrations (below MIC) would occur in 40% with 100mg, 21% with 200mg, and 9% with 400mg. AUC/MIC ratio >100 would occur in 53% for 400mg, 74% for 800mg, 83% for 1200mg, and 88% for 1600mg.

CONCLUSIONS

Currently recommended fluconazole doses may be inadequate for cryptococcosis. Further clinical studies are needed for rational fluconazole dose selection.

Diagnosis and Management of Central Nervous System Cryptococcal Infections in HIV-Infected Adults

Cryptococcal meningitis persists as a significant source of morbidity and mortality in persons with HIV/AIDS, particularly in sub-Saharan Africa. Despite increasing access to antiretrovirals, persons presenting with advanced HIV disease remains common, and Cryptococcus remains the most frequent etiology of adult meningitis. We performed a literature review and herein present the most up-to-date information on the diagnosis and management of cryptococcosis. Recent advances have dramatically improved the accessibility of timely and affordable diagnostics. The optimal initial antifungal management has been newly updated after the completion of a landmark clinical trial. Beyond antifungals, the control of intracranial pressure and mitigation of toxicities remain hallmarks of effective treatment. Cryptococcal meningitis continues to present challenging complications and continued research is needed.

Evaluation of a prison outreach clinic for the diagnosis and prevention of hepatitis C: implications for the national strategy

BACKGROUND

Hepatitis C virus (HCV) infection is a major public health problem recognised by the UK National Strategy that proposes that a care pathway for assessment, diagnosis, and treatment be established in all prisons, integrated within managed clinical networks. A prison sentence provides the opportunity to focus on traditionally hard to reach patients.

AIMS

To evaluate the prevalence of HCV infection in a UK prison cluster and to assess the effectiveness of a prison outreach service for hepatitis C.

SUBJECTS

Male prisoners.

METHODS

A nurse specialist led clinic within a cluster of adult prisons was established, offering health education on hepatitis C, advice on harm minimisation, and HCV testing. Infected prisoners were offered access to a care pathway leading to treatment. Outcome measures were uptake of the service, and diagnosis and treatment of hepatitis C.

RESULTS

A total of 8.5% of 1618 prisoners accepted testing: 30% had active infection with HCV. Most were ineligible for treatment due to psychiatric illness or did not receive treatment for logistic reasons. Injecting drug use was the major risk factor in all cases. Only 7% of HCV polymerase chain amplification positive inmates received treatment in prison.

CONCLUSION

There is a large pool of HCV infected prisoners at risk of complications, constituting a source of infection during their sentence and after discharge. A prison outreach clinic and care pathway was perceived as effective in delivering health education, reducing the burden on prison and hospital services. It provided an opportunity for intervention but had a limited effect in eradicating HCV in prisoners and it remains unclear how this might be achieved.