Recruitment of plasma cells from IL-21-dependent and IL-21-independent immune reactions to the bone marrow.

Bone marrow plasma cells (BMPC) are the correlate of humoral immunity, consistently releasing antibodies into the bloodstream. It remains unclear if BMPC reflect different activation environments or maturation of their precursors. Here we define human BMPC heterogeneity and track the recruitment of antibody-secreting cells (ASC) from SARS-CoV-2 vaccine immune reactions to the bone marrow (BM). Trajectories based on single-cell transcriptomes and repertoires of peripheral and BM ASC reveal sequential colonisation of BMPC compartments. In activated B cells, IL-21 suppresses CD19 expression, indicating that CD19low-BMPC are derived from follicular, while CD19high-BMPC originate from extrafollicular immune reactions. In primary immune reactions, both CD19low- and CD19high-BMPC compartments are populated. In secondary immune reactions, most BMPC are recruited to CD19high-BMPC compartments, reflecting their origin from extrafollicular reactivations of memory B cells. A pattern also observable in vaccinated-convalescent individuals and upon diphtheria/tetanus/pertussis recall-vaccination. Thus, BMPC diversity reflects the evolution of a given humoral immune response.

Altered increase in STAT1 expression and phosphorylation in severe COVID-19.

The interferon pathway, a key antiviral defense mechanism, is being considered as a therapeutic target in COVID-19. Both, substitution of interferon and JAK/STAT inhibition to limit cytokine storms have been proposed. However, little is known about possible abnormalities in STAT signaling in immune cells during SARS-CoV-2 infection. We investigated downstream targets of interferon signaling, including STAT1, STAT2, pSTAT1 and 2, and IRF1, 7 and 9 by flow cytometry in 30 patients with COVID-19, 17 with mild, and 13 with severe infection. We report upregulation of STAT1 and IRF9 in mild and severe COVID-19 cases, which correlated with the IFN-signature assessed by Siglec-1 (CD169) expression on peripheral monocytes. Interestingly, Siglec-1 and STAT1 in CD14+ monocytes and plasmablasts showed lower expression among severe cases compared to mild cases. Contrary to the baseline STAT1 expression, the phosphorylation of STAT1 was enhanced in severe COVID-19 cases, indicating a dysbalanced JAK/STAT signaling that fails to induce transcription of interferon stimulated response elements (ISRE). This abnormality persisted after IFN-α and IFN-γ stimulation of PBMCs from patients with severe COVID-19. Data suggest impaired STAT1 transcriptional upregulation among severely infected patients may represent a potential predictive biomarker and would allow stratification of patients for certain interferon-pathway targeted treatments.

De-novo malignancies after kidney transplantation: A long-term observational study.

BACKGROUND: De-novo malignancies after kidney transplantation represent one major cause for mortality after transplantation. However, most of the studies are limited due to small sample size, short follow-up or lack of information about cancer specific mortality. METHODS: This long-term retrospective analysis included all adult patients with complete follow-up that underwent kidney transplantation between 1995 and 2016 at our centre. All patients with diagnosis of malignancy excluding non-melanoma skin cancer (NMSC) were identified and a matched control group was assigned to the kidney transplant recipients with post-transplant malignancies. RESULTS: 1417 patients matched the inclusion criteria. 179 malignancies posttransplant were diagnosed in 154 patients (n = 21 with two, n = 2 patients with three different malignancies). Mean age at cancer diagnosis was 60.3±13.3 years. Overall incidence of de-novo malignancies except NMSC was 1% per year posttransplant. Renal cell carcinoma was the most common entity (n = 49, incidence 4.20 per 1000 patient years; cancer specific mortality 12%), followed by cancer of the gastro-intestinal tract (n = 30, 2.57; 50%), urinary system (n = 24, 2.06; 13%), respiratory system (n = 18, 1.54; 89%), female reproductive system (n = 15, 1.29; 13%), posttransplant lymphoproliferative disorders and haematological tumours (n = 14, 1.20; 21%), cancers of unknown primary (n = 7, 0.60 100%) and others (n = 22, 1.89; 27%). Male sex, re-transplantation and time on dialysis were associated with de-novo malignancies after transplantation. CONCLUSION: De-novo malignancies continue to be a serious problem after kidney transplantation. To improve long-term outcome after Kidney transplantation, prevention and cancer screening should be more tailored and intensified.

Role for antimalarials in the management of COVID-19.

PURPOSE OF REVIEW: The current review highlights recent insights into direct antiviral effects by antimalarials against severe acute respiratory syndrome (SARS)-CoV-2 and other viruses and their potential indirect effects on the host by avoiding exaggerated immune responses (reduced cytokine release, Toll-like receptor response, antigen presentation related to lysosomal processing). RECENT FINDINGS: Currently, there is a large debate on the use of antimalarials for prophylaxis and treatment of SARS-CoV-2-induced disease based on preclinical in-vitro data, small case series and extrapolation from earlier studies of their effect on intracellular pathogens, including many viruses. Hydroxychloroquine (HCQ) or chloroquine have not demonstrated robust efficacy in prior randomized controlled studies against several other viruses. In-vitro data indicate a reduced viral replication of SARS-CoV-2. Especially immunomodulatory effects of antimalarials might also contribute to a clinical efficacy. For SARS-CoV-2 various large studies will provide answers as to whether antimalarials have a place in prophylaxis or treatment of the acute virus infection with SARS-CoV-2 but compelling data are missing so far. SUMMARY: In-vitro data provide a theoretical framework for an efficacy of antimalarials in SARS-CoV-2-induced disease but clinical proof is currently missing.

A prospective study of daclatasvir and sofosbuvir in chronic HCV-infected kidney transplant recipients.

BACKGROUND: Only a few prospective trials exist regarding the use of novel direct-acting antiviral agents (DAAs) in kidney transplant recipients (KTR) with chronic hepatitis C virus (HCV) infection. METHODS: This prospective single-center trial evaluated treatment with daclatasvir (DCV) and sofosbuvir (SOF) over 12 weeks in 16 adult chronic HCV infected KTR and eGFR > 30 ml/min/1.73m2. Primary endpoint was sustained virological response 12 weeks after end of therapy (SVR12). Beside baseline liver biopsy, hepatic function and glucose metabolism were regularly assessed. RESULTS: Four of 16 study patients had previously failed interferon-based HCV treatment. Liver biopsy showed mostly moderate fibrosis score before therapy with DCV/SOF was initiated at a median of 10.3 years after transplantation. In total, 15 of 16 KTR achieved SVR12. One patient showed early viral relapse because of resistance-associated variants (RAVs) in the HCV NS5A region. Rescue treatment with SOF/velpatasvir/voxilaprevir resulted in SVR12. DAAs treatment led to significant improvement of liver metabolism and glucose tolerance accompanied with no therapy-associated major adverse events and excellent tolerability. CONCLUSIONS: Our study demonstrates safety, efficacy and functional benefit of DCV/SOF treatment in KTR with chronic HCV infection. We provide data on rescue strategies for treatment failures due to present RAVs and amelioration of hepatic function and glucose tolerance. TRIAL REGISTRATION: Registry name: European Clinical Trials Register; Trial registry number (Eudra-CT): 2014-004551-32 , Registration date: Aug 28th 2015.

Urinary NGAL-Positive Acute Kidney Injury and Poor Long-term Outcomes in Hospitalized Patients.

INTRODUCTION: Neutrophil gelatinase-associated lipocalin (NGAL) is a widely studied biomarker of renal tubular injury. Urinary NGAL (uNGAL) during acute kidney injury (AKI) predicts short-term adverse outcomes. However, the long-term predictive value is unknown. METHODS: We performed a prospective observational study of 145 patients with hospital-acquired AKI according to Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) criteria and analyzed the long-term predictive value of uNGAL at the time of AKI. We defined a composite outcome of all-cause mortality and the development of end-stage renal disease (ESRD). RESULTS: In all, 61 AKI patients died and 22 developed ESRD within 6 months. The uNGAL levels were significantly higher in patients with poor long-term outcomes. uNGAL levels ≥362 µg/l (highest quartile) and uNGAL levels between 95 and 362 µg/l (third quartile) were associated with hazard ratios of 3.7 (95% confidence interval, 2.1-6.5) and 1.9 (1.1-3.5), respectively, compared with uNGAL levels <95 µg/l (lower quartiles). After 6 months, 67% and 43% of patients within the highest and third uNGAL quartile, respectively, had either progressed to ESRD or died, compared to only 21% of patients with uNGAL in the lower 2 quartiles (P < 0.001). In multivariable Cox regression analyses accounting for conventional predictors, uNGAL was the strongest independent predictor of adverse long-term outcomes. The association of uNGAL levels and poor long-term outcomes remained significant in the subgroup of 107 AKI survivors discharged without requiring dialysis (P = 0.002). DISCUSSION: These data indicate that elevated uNGAL levels at AKI diagnosis predict poor long-term outcomes.