Short- and long-term T cell and antibody responses following Dexamethasone treatment in COVID-19

BACKGROUND

After its introduction as standard-of-care for severe COVID-19, dexamethasone has been administered to a large number of patients globally. Detailed knowledge of its impact on the cellular and humoral immune response to SARS-CoV-2 remains scarce.

METHODS

We included immunocompetent individuals with 1) mild COVID-19, 2) severe COVID-19 before introduction of dexamethasone treatment, and 3) severe COVID-19 infection treated with dexamethasone from prospective observational cohort studies at Charité-Universitätsmedizin Berlin, Germany. We analyzed SARS-CoV-2 spike-reactive T cells, spike-specific IgG titers as well as serum neutralizing activity against B.1.1.7, B.1.617.2 in samples ranging from two weeks to six months post infection. We also analyzed BA.2 neutralization in sera after booster immunization.

RESULTS

Patients with severe COVID-19 and dexamethasone treatment had lower T cell and antibody responses to SARS-CoV-2 compared to patients without dexamethasone treatment in the early phase of disease, which converged in both groups before six months post infection and also post-immunization. Patients with mild COVID-19 had a comparatively lower T cell and antibody response than patients with severe disease, including a lower response to booster-immunization during convalescence.

CONCLUSION

Dexamethasone treatment is associated with short-term reduction of T cell and antibody response in severe COVID-19 when compared to the non-treated group, but this difference evens out six months after infection. We confirm higher cellular and humoral immune responses in patients after severe versus mild COVID-19 infection and the concept of improved hybrid immunity upon immunization.

TRIAL REGISTRATION

n/aFunding: Berlin Institute of Health, German Federal Ministry of Education and German Federal Institute for Drugs and Medical Devices.

Performance of Field's Stain Compared with Conventional Giemsa Stain for the Rapid Detection of Blood Microfilariae in Gabon

Filarial infections caused by Loa loa and Mansonella perstans are a considerable public health burden in rural regions of Central Africa. Rapid diagnostic tools for the detection of microfilariae in the blood are needed. Field's stain is a rapid staining technique for microscopic slides originally established for malaria diagnostics. It requires less than 1 minute of staining compared with conventional staining protocols requiring at least 15 to 20 minutes for staining and could thus significantly accelerate diagnostics for human filariasis. Here we evaluated Field's stain as a rapid staining technique in comparison to Giemsa stain for the detection of microfilariae in peripheral blood. Blood smears were collected from 175 participants residing in the region of Lambaréné and Fougamou, Gabon. Each participant's samples were stained in parallel with Field's stain and conventional Giemsa stain. Slides were then microscopically assessed and compared for qualitative and quantitative results by a blinded assessor for the two endemic filarial blood pathogens M. perstans and L. loa. Field's stain shows excellent diagnostic performance characteristics for L. loa microfilariae compared with Giemsa staining. Concordance was favorable for M. perstans although lower than for L. loa. Field's stain offers a rapid alternative to Giemsa stain for detection of L. loa microfilariae in thick blood smears. This could help accelerate diagnostics of blood filarial pathogens in mass screening programs or resource constrained health care institutions with high patient load.

A Prospective Study on the Impact and Out-of-Pocket Costs of Dengue Illness in International Travelers

Although the costs of dengue illness to patients and households have been extensively studied in endemic populations, international travelers have not been the focus of costing studies. As globalization and human travel activities intensify, travelers are increasingly at risk for emerging and reemerging infectious diseases, such as dengue. This exploratory study aims to investigate the impact and out-of-pocket costs of dengue illness among travelers. We conducted a prospective study in adult travelers with laboratory-confirmed dengue and recruited patients at travel medicine clinics in eight different countries from December 2013 to December 2015. Using a structured questionnaire, we collected information on patients and their health-care utilization and out-of-pocket expenditures, as well as income and other financial losses they incurred because of dengue illness. A total of 90 patients participated in the study, most of whom traveled for tourism (74%) and visited countries in Asia (82%). Although 22% reported hospitalization and 32% receiving ambulatory care while traveling, these percentages were higher at 39% and 71%, respectively, after returning home. The out-of-pocket direct and indirect costs of dengue illness were US$421 (SD 744) and US$571 (SD 1,913) per episode, respectively, averaging to a total out-of-pocket cost of US$992 (SD 2,052) per episode. The study findings suggest that international travelers incur important direct and indirect costs because of dengue-related illness. This study is the first to date to investigate the impact and out-of-pocket costs of travel-related dengue illness from the patient's perspective and paves the way for future economic burden studies in this population.

Longitudinal course of ante- and postpartum generalized anxiety symptoms and associated factors in West-African women from Ghana and Côte d'Ivoire

BACKGROUND

Little is known about the course of perinatal anxiety, particularly in low and middle income countries. This study aimed at examining trajectories of ante- and postpartum generalized anxiety symptoms in West-African women and their associations with mother and child characteristics.

METHODS

778 women from Côte d'Ivoire and Ghana were investigated between 04/2010 and 03/2014. Anxiety symptoms were measured using the seven-item Generalized Anxiety Disorder scale (GAD-7) at three months antepartum and three, 12 and 24 months postpartum. Growth mixture modeling was applied to identify latent trajectory classes of anxiety. Multinomial logistic regression was used to investigate the associations of psychosocial, sociodemographic, obstetric and clinical characteristics with different trajectories.

RESULTS

Four distinct trajectories of anxiety were identified. The majority of women (79.8%) had consistent low anxiety symptoms, while 11.4% had elevated anxiety scores before and around childbirth that decreased gradually. 5.4% of women showed increasing anxiety symptoms over time. Few women (3.3%) had transient anxiety with elevated scores at three and 12 months postpartum. Risk factors for elevated anxiety levels around childbirth were antepartum depressive symptoms, higher levels of stress (economic, marital and social stress), lower child birth weight, and multiparity. Partner support was found to be protective.

LIMITATIONS

Anxiety symptoms were assessed using a screening instrument and not through a formal diagnostic classification system. Some putative risk factors were not investigated, and some psychosocial factors were assessed retrospectively.

CONCLUSION

The presence of different trajectories underline the importance of monitoring anxiety symptoms in pregnant women and in mothers with infants/toddlers.

Group B Streptococci serotype distribution in pregnant women in Ghana: assessment of potential coverage through future vaccines

OBJECTIVE

Group B streptococcal (GBS) colonization of pregnant women can lead to subsequent infection of the new-born and potentially fatal invasive disease. Data on GBS colonization prevalence and serotype distribution from Africa are scarce, although GBS-related infections are estimated to contribute substantially to infant mortality. In recent years, GBS vaccine candidates provided promising results in phase I and II clinical trials. We aimed to assess the prevalence and serotype distribution of GBS in Ghana since this knowledge is a prerequisite for future evaluation of vaccine trials.

METHODS

This double-centre study was conducted in one rural and one urban hospital in central Ghana, West Africa. Women in late pregnancy (≥35 weeks of gestation) attending the antenatal care clinic (ANC) provided recto-vaginal swabs for GBS testing. GBS isolates were analysed for serotype and antibiotic susceptibility. GBS-positive women were treated with intrapartum antibiotic prophylaxis (IAP) according to current guidelines of the Center for Disease Control and Prevention (CDC).

RESULTS

In total, 519 women were recruited at both study sites, recto-vaginal swabs were taken from 509. The overall prevalence of GBS was 19.1% (18.1% in rural Pramso and 23.1% in urban Kumasi, restrospectively). Capsular polysaccharide serotype (CPS) Ia accounted for the most frequent serotype beyond all isolates (28.1%), followed by serotype V (27.1%) and III (21.9%). No resistance to Penicillin was found, resistances to second line antibiotics clindamycin and erythromycin were 3.1% and 1%, respectively.

DISCUSSION

Group B Streptococcus serotype distribution in Ghana is similar to that worldwide, but variations in prevalence of certain serotypes between the urban and rural study site were high. Antibiotic resistance of GBS strains was surprisingly low in this study.

Mental health related determinants of parenting stress among urban mothers of young children--results from a birth-cohort study in Ghana and Côte d'Ivoire

BACKGROUND

There are limited data on the parenting stress (PS) levels in sub-Saharan African mothers and on the association between ante- and postnatal depression and anxiety on PS.

METHODS

A longitudinal birth cohort of 577 women from Ghana and Côte d'Ivoire was followed from the 3rd trimester in pregnancy to 2 years postpartum between 2010 and 2013. Depression and anxiety were assessed by the Patient Health Questionnaire depression module (PHQ-9) and the Generalized Anxiety Disorder (GAD-7) at baseline, 3 month, 12 month and 24 month postpartum. PS was measured using the Parenting Stress Index-Short Form (PSI-SF) at 3, 12 and 24 month. The mean total PS score and the subscale scores were compared among depressed vs. non-depressed and among anxious vs. non-anxious mothers at 3, 12 and 24 month postpartum. The proportions of clinical PS (PSI-SF raw score > 90) in depressed vs. non-depressed and anxious vs. non-anxious mothers were also compared. A generalized estimating equation (GEE) approach was used to estimate population-averaged associations between women's depression/anxiety and PS adjusting for age, child sex, women's anemia, education, occupation, spouse's education, and number of sick child visits.

RESULTS

A total of 577, 531 and 264 women completed the PS assessment at 3 month, 12 month and 24 month postpartum across the two sites and the prevalences of clinical PS at each time point was 33.1%, 24.4% and 14.9% in Ghana and 30.2%, 33.5% and 22.6% in Côte d'Ivoire, respectively. At all three time points, the PS scores were significantly higher among depressed mothers vs. non-depressed mothers. In the multivariate regression analyses, antepartum and postpartum depression were consistently associated with PS after adjusting for other variables.

CONCLUSIONS

Parenting stress is frequent and levels are high compared with previous studies from high-income countries. Antepartum and postpartum depression were both associated with PS, while antepartum and postpartum anxiety were not after adjusting for confounders. More quantitative and qualitative data are needed in sub-Saharan African populations to assess the burden of PS and understand associated mechanisms. Should our findings be replicated, it appears prudent to design and subsequently evaluate intervention strategies.

Association of antepartum and postpartum depression in Ghanaian and Ivorian women with febrile illness in their offspring: a prospective birth cohort study

In low-income countries, perinatal depression is common, but longitudinal data on its influence on child health are rare. We examined the association between maternal depression and febrile illness in children. There were 654 mother/child dyads in Ghana and Côte d'Ivoire that were enrolled in a prospective birth cohort in 2010-2011 and underwent 2-years of follow up. Mothers were examined for depression using the Patient Health Questionnaire depression module antepartum and 3 and 12 months postpartum. The hazard of febrile illness in children of depressed and nondepressed mothers was estimated using a recurrent event Cox proportional hazards model. The prevalences of antepartum depression in mothers from Côte d'Ivoire and Ghana were 28.3% and 26.3%, respectively. The prevalences of depression at 3 and 12 months postpartum were 11.8% and 16.1% (Côte d'Ivoire) and 8.9% and 7.2% (Ghana). The crude and adjusted (for country and socioeconomic status) hazard ratios of febrile illness in children of depressed mothers compared with those in children of nondepressed mothers were 1.57 (95% confidence interval: 1.20, 2.07) and 1.32 (95% confidence interval: 1.01, 1.74) respectively. Perinatal depression was frequent and associated with febrile illness in the offspring. Our results showed that a high prevalence of depression in sub-Saharan Africa may pose a serious public health threat to women and their offspring.

BDNF/TrkB signaling regulates HNK-1 carbohydrate expression in regenerating motor nerves and promotes functional recovery after peripheral nerve repair

Functional recovery after peripheral nerve injury is often poor despite high regenerative capacity of peripheral neurons. In search for novel treatments, brief electrical stimulation of the acutely lesioned nerve has recently been identified as a clinically feasible approach increasing precision of axonal regrowth. The effects of this stimulation appear to be mediated by BDNF and its receptor, TrkB, but the down-stream effectors are unknown. A potential candidate is the HNK-1 carbohydrate known to be selectively reexpressed in motor but not sensory nerve branches of the mouse femoral nerve and to enhance growth of motor but not sensory axons in vitro. Here, we show that short-term low-frequency electrical stimulation (1 h, 20 Hz) of the lesioned and surgically repaired femoral nerve in wild-type mice causes a motor nerve-specific enhancement of HNK-1 expression correlating with previously reported acceleration of muscle reinnervation. Such enhanced HNK-1 expression was not observed after electrical stimulation in heterozygous BDNF or TrkB-deficient mice. Accordingly, the degree of proper reinnervation of the quadriceps muscle, as indicated by retrograde labeling of motoneurons, was reduced in TrkB+/- mice compared to wild-type littermates. Also, recovery of quadriceps muscle function, evaluated by a novel single-frame motion analysis approach, and axonal regrowth into the distal nerve stump, assessed morphologically, were considerably delayed in TrkB+/- mice. These findings indicate that BDNF/TrkB signaling is important for functional recovery after nerve repair and suggest that up-regulation of the HNK-1 glycan is linked to this phenomenon.

Impacts of lesion severity and tyrosine kinase receptor B deficiency on functional outcome of femoral nerve injury assessed by a novel single-frame motion analysis in mice

Functional recovery after peripheral nerve injury is often poor. Comprehension of cellular and molecular mechanisms limiting or promoting restoration of function and design of efficient therapeutic approaches remain serious challenges for neuroscience and medicine. Progress has been restricted by the lack of reliable methods for evaluation of motor functions in laboratory animals. We describe a novel approach for assessment of muscle function in mice after femoral nerve damage, an injury causing impairment of knee extension. The functional deficit can be precisely estimated by angle and distance measurements on single video frames recorded during movements of the animals with or without body weight support. Using this method we describe here the precise time-course and degree of functional recovery after femoral nerve crush and transection. In addition, we show that restoration of function is considerably impaired in mice with a reduced expression level of the tyrosine kinase receptor B, a cognate receptor for the neurotrophin brain-derived neurotrophic factor. This finding is consistent with known functions of brain-derived neurotrophic factor and tyrosine kinase receptor B and demonstrates the potential of the method. The principles of the approach are highly relevant for the development of novel functional assays in other peripheral and, in particular, central nervous system injury paradigms.