Cases of Impaired Oxidative Burst in HIV-Exposed Uninfected Infants’ Neutrophils—A Pilot Study

An increased risk of serious bacterial infections in HIV-exposed uninfected (HEU) infants has been demonstrated. Although neutrophils are essential for the protection of infants against bacterial infections, no study has investigated their profile in HEU infants to date. In this study, we assessed the function of neutrophils in HEU infants using the nitroblue tetrazolium reduction test. Among 25 HEU infants, 9 (36%) showed a reduced ability of their neutrophils to produce reactive oxygen species upon stimulation with bacteria. No alteration of total neutrophil counts was noted in the blood of HEU infants indicating that the alteration observed in the 36% of HEU infants may only be functional. Conclusively, impaired neutrophil function could be a factor of vulnerability in HEU infants

Changes of C-reactive protein and Procalcitonin after four weeks of treatment in patients with pulmonary TB

Objective: Tuberculosis (TB) remains a public health concern worldwide, affecting millions of people every year. Detailed characterization of disease pathophysiology is key to proper diagnosis, disease progression, or treatment follow-up and evaluation. The present study investigated C-reactive protein and Procalcitonin (PCT) as candidate markers of early treatment response and disease activity. Methods: From September to December 2019, 21 HIV-negative consecutive TB patients were recruited, within the setting of the Gabonese TB specialized hospital and the National Laboratory of Public Health, in a prospective study. CRP and PCT levels were measured by chemiluminescence at diagnosis and 4 weeks following the initiation of anti-TB treatment. Results: The mean concentration of CRP in TB patients was 114.7 mg/L (95 % CI: [83.8–145.6]) at diagnosis and 20.2 mg/L (95 % CI: [14.1–26.4]) 4 weeks following anti-TB treatment. The drop in CRP concentrations between diagnosis, and week 4 following anti-TB treatment showed was significant (p < 0.0001). The average concentration of PCT at the time of diagnosis was 0.3 ng/mL (95 % CI: [0.19–0.41]). PCT Concentration dropped below 0.05 ng/mL 4 weeks following the start of anti-TB treatment (p < 0.01). Conclusion: CRP and PCT are potential TB biomarkers, each, carrying important keys. If the drop in both proteins may indicate a significant reduction of the Mtb burden, the maintenance of CRP above the inflammation threshold could indicate the presence of residual bacilli. However, the clinical translation of the present finding will require more investigation

Increased Platelets Count in HIV-1 Uninfected Infants Born from HIV-1 Infected Mothers

HIV-exposed uninfected infants (HEU) represent a growing population in developing countries including Gabon. Several studies have shown the vulnerability of these infants toward infectious diseases. The aim of the study was to contribute to the global effort to understand how HIVexposure or anti retroviral therapy affects infants’ blood elements. We assessed HEU infants’ complete blood count using a blood analyzer instrument. Our investigations showed that among the observed clinically relevant hematological abnormalities events, thrombocytosis was the most prevalent clinically relevant hematological abnormality associated with HEU infants’. We showed that HEU infants had significantly higher platelets count than HUinfants. Therefore, higher level of platelets seems to characterize HEU infants when compared to HU infants

Altered Toll-Like Receptor-4 Response to Lipopolysaccharides in Infants Exposed to HIV-1 and Its Preventive Therapy

Pathogen sensing and recognition through pattern recognition receptors, and subsequent production of pro-inflammatory cytokines, is the cornerstone of the innate immune system. Despite the fact that HIV-exposed uninfected (HEU) infants are prone to serious bacterial infections, no study has focused on the functionality of their bacteria recognition system. This is the first study to investigate baseline levels of three critically important immune response molecules in this population: complement component (C)-3, toll-like receptor (TLR)-4, and C-reactive protein (CRP). We enrolled 16 HEU and 6 HIV-unexposed (HU) infants. TLR4 function was investigated by stimulating whole blood with increasing concentrations of TLR4-agonist ultrapure lipopolysaccharides. TLR4/TLR4-agonist dose response were assessed by measuring IL-6 secretion. Complement C3 and CRP were measured by photo spectrometry. Data showed no significant differences in baseline concentration of CRP between HEU and HU infants. Complement C3 was significantly higher in HEU infants than HU infants. TLR4 anergy was observed in 7 of 12 HEU infants, whereas the rest of HEU infants (n = 4) and the control HU infants tested (n = 3) showed responsive TLR4. None of the HEU infants investigated in this study had severe infections in the year after their birth. In conclusion, TLR4 anergy can occur in HEU infants without necessarily translating to increased vulnerability to infectious diseases

Evidence and implications of pre‐existing humoral cross‐reactive immunity to SARS‐CoV‐2

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has emerged throughout the world. Building knowledge around Covid‐19 is crucial to devise facts based approaches to respond efficiently against this pandemic. AIM: We aimed to investigate pre‐existing humoral cross‐reactive immunity to SARS‐CoV‐2. METHOD: We have tested the reactivity against SARS‐CoV‐2 nucleocapsid (N) antigen of sera collected from healthy healthcare volunteers in 2014. We assessed immunoglobulins reactive against SARS‐CoV‐2 N‐antigen using a well‐validated serological platform; Elecsys assay. RESULTS: Sera from 32 subjects (out of 135 [23.7%]) were reactive to SARS‐CoV‐2 N‐antigen, suggesting the presence of anti‐SARS‐CoV‐2 N‐antigen antibodies. CONCLUSION: Although the clinical relevance of the observed reactivity can only be speculated and needs to be investigated, the implication of this finding for coronavirus disease 2019 seroepidemiological survey and vaccines' clinical trials is critical