Intestinal Candida albicans overgrowth in IgA deficiency.

BACKGROUND: Secretory IgA interacts with commensal bacteria, but its impact on human mycobiota ecology has not been widely explored. In particular, whether human IgA-deficiency is associated with gut fungal dysbiosis remains unknown. OBJECTIVES: Our goal was to study the impact of IgA on gut mycobiota ecology. METHODS: The Fungi-Flow method was used to characterize fecal, systemic, and maternal IgA, IgM, and IgG responses against 14 representative fungal strains (yeast/spores or hyphae forms) in healthy donors (HDs) (n = 34, 31, and 20, respectively) and to also compare gut mycobiota opsonization by secretory antibodies in HDs (n = 28) and patients with selective IgA deficiency (SIgAd) (n = 12). Stool mycobiota composition was determined by internal transcribed spacer gene sequencing in HDs (n = 23) and patients with SIgAd (n = 17). Circulating CD4+ T-cell cytokine secretion profiles were determined by intracellular staining. The impact of secretory IgA, purified from breast milk (n = 9), on Candidaalbicans growth and intestinal Caco-2 cell invasion was tested in vitro. RESULTS: Homeostatic IgA binds commensal fungi with a body fluid-selective pattern of recognition. In patients with SIgAd, fungal gut ecology is preserved by compensatory IgM binding to commensal fungi. Gut Calbicans overgrowth nevertheless occurs in this condition but only in clinically symptomatic patients with decreased TH17/TH22 T-cell responses. Indeed, secretory IgA can reduce in vitro budding and invasion of intestinal cells by Calbicans and therefore exert control on this pathobiont. CONCLUSION: IgA has a selective impact on Calbicans ecology to preserve fungal-host mutualism.

Real-life use of mTOR inhibitor-based therapy in adults with autoimmune cytopenia highlights strong efficacy in relapsing/refractory multi-lineage autoimmune cytopenia.

Data on mTOR inhibitors (mTORi) in autoimmune cytopenia (AIC), in adults are scarce. We retrospectively analysed 30 cases of refractory or relapsing AIC treated with an mTORi-based therapy. Eleven warm autoimmune hemolytic anaemia, 10 autoimmune thrombocytopenia, 6 acquired pure red cell aplasia, 3 autoimmune neutropenia were included. Twenty were multilineage AIC (67%) and 21 were secondary AIC (70%). mTORi were associated with other therapies in 23 AIC (77%). Twenty-two AIC (73%) responded to mTORi-based therapy: 5 reached a partial response (17%) and 17 a complete response (57%). Survival without unfavourable outcome (failure, requirement of a new therapy, or death) was longer in multilineage AIC compared to single-lineage AIC (p = 0.049) with a median event-free survival of 48 versus 12 months. Median event-free survival was 48 months in secondary AIC and 33 months in primary AIC (p = 0.79). mTORi were discontinued in 4 patients (15%) for safety reasons and in 3 patients for patient's choice (12%). In conclusion, mTORi could be considered as an alternative or an add-on therapy in refractory or relapsing AIC in adult patients, especially in multilineage AIC.

Characteristics of thrombocytopenia, anasarca, fever, reticulin fibrosis and organomegaly syndrome: a retrospective study from a large Western cohort.

Idiopathic multicentric Castleman disease (iMCD) is a non-clonal inflammatory lymphoproliferative disorder of unknown origin. Recently, TAFRO syndrome (thrombocytopenia, anasarca, fever, reticulin fibrosis and organomegaly) emerged as a singular variant of iMCD in Asia and was associated with a severe course and a poor outcome. The present study describes the first large Western cohort of TAFRO syndrome patients (n = 25) meeting the All Japan TAFRO Syndrome Research Group diagnostic criteria. Characteristics of TAFRO patients were compared to iMCD-not otherwise specified (iMCD-NOS) patients used as a control group (n = 43). Our results show that despite baseline characteristics in accordance with previously reported series, Western TAFRO syndrome patients do not appear to present with a worse outcome than iMCD-NOS patients. There were no significant differences between the two groups regarding treatment choice, response to rituximab (71% vs. 67%) or tocilizumab (69% vs. 91%) in TAFRO and iMCD-NOS, respectively. The two-year overall survival was above 95% in both groups. Limits of inclusion and exclusion criteria for TAFRO definition are also discussed. Our findings raise the question of the singularity of the TAFRO entity in Western countries. The data should promote further research using unsupervised models to identify markers of disease severity in Western cohorts of iMCD patients.

Campylobacter infection in 4 patients treated with ibrutinib.

Ibrutinib is a Bruton tyrosine kinase (BTK) inhibitor used in B-cell lymphoproliferative disorders. Patients with genetic BTK deficiency are susceptible to recurrent and severe Campylobacter infections. We report 4 patients treated with ibrutinib who developed chronic or extra-digestive campylobacteriosis resembling ibrutinib-related adverse events including diarrhea (n = 4), panniculitis (n = 2), and arthritis (n = 1). Microbiological explorations identified Campylobacter jejuni (n = 3) or Campylobacter coli (n = 1). All the patients completely recovered after a short course of oral antibiotic therapy. In patients treated with ibrutinib presenting with chronic diarrhea, dermatological, or rheumatological manifestations, campylobacteriosis should be ruled out before attributing the symptoms to ibrutinib and discuss its discontinuation.

From Dysgammaglobulinemia to Autosomal-Dominant Activation-Induced Cytidine Deaminase Deficiency: Unraveling an Inherited Immunodeficiency after 50 Years.

The genetic investigation of a family presenting with a dominant form of hyper IgM syndrome published in 1963 and 1975 revealed a R190X nonsense mutation in activation-induced cytidine deaminase. This report illustrates the progress made over 6 decades in the characterization of primary immunodeficiencies, from immunochemistry to whole-exome sequencing.

Synergistic convergence of microbiota-specific systemic IgG and secretory IgA.

BACKGROUND: Commensals induce local IgA responses essential to the induction of tolerance to gut microbiota, but it remains unclear whether antimicrobiota responses remain confined to the gut. OBJECTIVE: The aim of this study was to investigate systemic and intestinal responses against the whole microbiota under homeostatic conditions and in the absence of IgA. METHODS: We analyzed blood and feces from healthy donors, patients with selective IgA deficiency (SIgAd), and patients with common variable immunodeficiency (CVID). Immunoglobulin-coated bacterial repertoires were analyzed by using combined bacterial fluorescence-activated cell sorting and 16S rRNA sequencing. Bacterial lysates were probed by using Western blot analysis with healthy donor sera. RESULTS: Although absent from the healthy gut, serum antimicrobiota IgG are present in healthy subjects and increased in patients with SIgAd. IgG converges with nonoverlapping secretory IgA specificities to target the same bacteria. Each individual subject targets a diverse microbiota repertoire with a proportion that correlates inversely with systemic inflammation. Finally, intravenous immunoglobulin preparations target CVID gut microbiota much less efficiently than healthy microbiota. CONCLUSION: Secretory IgA and systemic IgG converge to target gut microbiota at the cellular level. SIgAd-associated inflammation is inversely correlated with systemic anticommensal IgG responses, which might serve as a second line of defense. We speculate that patients with SIgAd could benefit from oral IgA supplementation. Our data also suggest that intravenous immunoglobulin preparations can be supplemented with IgG from IgA-deficient patient pools to offer better protection against gut bacterial translocations in patients with CVID.

Treatment and outcome of Unicentric Castleman Disease: a retrospective analysis of 71 cases.

We retrospectively analysed 71 cases of Unicentric Castleman disease, a rare, usually asymptomatic, benign lymphoproliferative disorder presenting as a unique nodal mass. Although surgery is considered as the gold standard therapy, only 38 patients (54%) underwent initial surgical resection and 95% were cured. An additional 9 patients had surgery after an attempt at medical reduction. Reduction therapy was used in 21 patients with a 55% response rate, but without evidence for an optimal regimen. Radiotherapy was limited to 8 patients because of associated toxicity. Watch and wait was considered in 13 asymptomatic patients and 11 of these remained stable for up to 17 years.

Bortezomib and dexamethasone, an original approach for treating multi-refractory warm autoimmune haemolytic anaemia.

We report the off-label use of bortezomib combined with dexamethasone in eight adults with severe and multi-refractory warm auto-immune haemolytic anaemia (wAIHA). After six cycles of induction therapy, 6 of the 8 patients achieved response (3 complete response, 3 response). Response was obtained after a median of 2 (1-4) cycles. After a median follow-up of 14 (6-36) months, six patients maintained a response (bortezomib/dexamethasone maintenance, n = 4); five patients experienced at least one moderate adverse event, including peripheral neuropathy (n = 2). These results suggest that bortezomib/dexamethasone combination is a promising approach with acceptable toxicity for treating severe refractory wAIHA in adults.

Iron deficiency, an unusual cause of thrombocytopenia: results from a multicenter retrospective case-controlled study.

Iron deficiency anemia (IDA) is often associated with mild to moderate thrombocytosis, and iron deficiency-associated thrombocytopenia (IDAT) is much more uncommon and often misdiagnosed as immune thrombocytopenia (ITP). To better describe the features of IDAT, we conducted a retrospective multicenter case-control study. We identified 10 patients (9 women) with a definite diagnosis IDAT, with a median age of 43.5 [range, 16-72] years and a median platelet count of 30.5 × 109/L [range, 21-80], and 7 patients with a possible diagnosis of IDAT. Bleeding manifestations were absent in all patients but one. All the patients recovered (platelet count ≥ 150 × 109/L) upon iron therapy ± red blood cell transfusion after a median time of 6 [4-39] days. When compared with 30 randomly newly diagnosed ITP patients matched on age, the baseline platelet count was significantly lower in ITP (median = 7 × 109/L [4-59], p < 0.001) whereas MPV was higher (10.5 fL [9,4-13,8] vs 8.2 fL, for IDAT p < 0.001). The median platelet count on day 7 was 337 × 109/L [113-1000] for IDAT cases vs 72 × 109/L [13-212] for ITP controls (p < 0.001). IDAT is potentially an under-recognized cause of thrombocytopenia that may be easily managed with iron therapy.

Quality control of microbiota metagenomics by k-mer analysis.

BACKGROUND: The biological and clinical consequences of the tight interactions between host and microbiota are rapidly being unraveled by next generation sequencing technologies and sophisticated bioinformatics, also referred to as microbiota metagenomics. The recent success of metagenomics has created a demand to rapidly apply the technology to large case-control cohort studies and to studies of microbiota from various habitats, including habitats relatively poor in microbes. It is therefore of foremost importance to enable a robust and rapid quality assessment of metagenomic data from samples that challenge present technological limits (sample numbers and size). Here we demonstrate that the distribution of overlapping k-mers of metagenome sequence data predicts sequence quality as defined by gene distribution and efficiency of sequence mapping to a reference gene catalogue. RESULTS: We used serial dilutions of gut microbiota metagenomic datasets to generate well-defined high to low quality metagenomes. We also analyzed a collection of 52 microbiota-derived metagenomes. We demonstrate that k-mer distributions of metagenomic sequence data identify sequence contaminations, such as sequences derived from "empty" ligation products. Of note, k-mer distributions were also able to predict the frequency of sequences mapping to a reference gene catalogue not only for the well-defined serial dilution datasets, but also for 52 human gut microbiota derived metagenomic datasets. CONCLUSIONS: We propose that k-mer analysis of raw metagenome sequence reads should be implemented as a first quality assessment prior to more extensive bioinformatics analysis, such as sequence filtering and gene mapping. With the rising demand for metagenomic analysis of microbiota it is crucial to provide tools for rapid and efficient decision making. This will eventually lead to a faster turn-around time, improved analytical quality including sample quality metrics and a significant cost reduction. Finally, improved quality assessment will have a major impact on the robustness of biological and clinical conclusions drawn from metagenomic studies.

Higher rate of progression in HIV- than in HIV+ patients after rituximab for HHV8+ multicentric Castleman disease.

Rituximab has revolutionized the treatment of Kaposi sarcoma-associated herpesvirus/human herpesvirus 8-associated multicentric Castleman disease (HHV8+ MCD), converting a rapidly fatal illness into a relapsing disease. HHV8+ MCD mainly affects patients with HIV infection but can also be observed in patients without HIV infection. We retrospectively analyzed a cohort of 99 patients (73 who tested HIV+ and 26 who tested HIV-), with HHV8+ MCD treated with rituximab-based therapy. Baseline characteristics were similar in patients who had HIV- and HIV+ results, although those who tested HIV- were older (65 vs 42 years) and presented less frequently with Kaposi sarcoma (15% vs 40%). Ninety-five patients (70 HIV+ and 25 HIV-) achieved complete remission (CR) after rituximab-based therapy. After a median follow-up of 51 months, 36 patients (12 HIV- and 24 HIV+) experienced disease progression. The 5-year progression-free survival (PFS) was 54%. The 5-year PFS was lower in HIV- patients than in HIV+ patients : 26% and 62%, respectively (P = .02). A multivariate prognostic factors analysis including time-dependent covariates revealed that HIV- status, reoccurrence of HHV8 DNA >3 log copies per mL, and serum C-reactive protein (CRP) >20 mg/mL were independently associated with an increased risk of progression after rituximab-induced CR (P = .001; P = .01; and P = .01, respectively). The lower rate of progression observed in the population with HIV+ results despite a longer follow-up period might have resulted from the possible immune restoration upon antiretroviral therapy. HHV8 viral load and serum CRP monitoring after rituximab therapy provide information on the progression risk and may help in the decision to resume specific therapy.

Post-traumatic stress disorder and quality of life alterations in survivors of immune-mediated thrombotic thrombocytopenic purpura and atypical hemolytic and uremic syndrome.

Thrombotic thrombocytopenic purpura (iTTP) and atypical hemolytic-uremic syndrome (aHUS), once in remission, may cause long-term symptoms, among which mental-health impairments may be difficult to detect. We conducted telephone interviews 72 [48-84] months after ICU discharge to assess symptoms of anxiety, depression, and posttraumatic stress disorder (PTSD) and the 36-item Short Form questionnaire (SF-36). Of 103 included patients, 52 had iTTP and 51 aHUS; 74% were female, median age was 39 y (31-54), and 39 (38%) patients were still taking treatment. Symptoms of anxiety, PTSD and depression were present in 50%, 27% and 14% of patients, respectively, with no significant difference between the iTTP and aHUS groups. Patients with PTSD symptoms had significantly greater weight gain and significantly worse perceived physical and/or emotional wellbeing, anxiety symptoms, and depression symptoms. The SF-36 physical and mental components indicated significantly greater quality-of-life impairments in patients with vs. without PTSD symptoms and in those with aHUS and PTSD vs. iTTP with or without PTSD. In the aHUS group, quality of life was significantly better in patients with vs. without eculizumab treatment. Factors independently associated with PTSD symptoms were male sex (odds ratio [OR], 0.11; 95%CI, 0.02-0.53), platelet count ≤20 G/L at acute-episode presentation (OR, 2.68; 1.01-7.38), and current treatment (OR, 2.69; 95%CI, 1.01-7.36). Mental-health screening should be routine in patients with iTTP and aHUS to ensure appropriate care.

A neomorphic mutation in the interferon activation domain of IRF4 causes a dominant primary immunodeficiency.

Here, we report on a heterozygous interferon regulatory factor 4 (IRF4) missense variant identified in three patients from a multigeneration family with hypogammaglobulinemia. Patients' low blood plasmablast/plasma cell and naïve CD4 and CD8 T cell counts contrasted with high terminal effector CD4 and CD8 T cell counts. Expression of the mutant IRF4 protein in control lymphoblastoid B cell lines reduced the expression of BLIMP-1 and XBP1 (key transcription factors in plasma cell differentiation). In B cell lines, the mutant IRF4 protein as wildtype was found to bind to known IRF4 binding motifs. The mutant IRF4 failed to efficiently regulate the transcriptional activity of interferon-stimulated response elements (ISREs). Rapid immunoprecipitation mass spectrometry of endogenous proteins indicated that the mutant and wildtype IRF4 proteins differed with regard to their respective sets of binding partners. Our findings highlight a novel mechanism for autosomal-dominant primary immunodeficiency through altered protein binding by mutant IRF4 at ISRE, leading to defective plasma cell differentiation.

Etoposide treatment in secondary hemophagocytic syndrome: impact on healthcare-associated infections and survival.

BACKGROUND: Etoposide remains the cornerstone of symptomatic management of critically ill patients with secondary hemophagocytic syndrome (sHS). Risk of healthcare-associated infections (HAIs) in this setting with etoposide has never been assessed. We sought to evaluate the association between etoposide administration, HAIs occurrence and survival in critically ill adult patients with sHS. In this retrospective single-center study conducted in a university hospital ICU between January 2007 and March 2020, all consecutive patients with sHS were included. HAIs were defined as any microbiologically documented infection throughout ICU stay. Competing risk survival analysis was performed to determine factors associated with HAIs. Propensity score-based overlap weighting was performed to adjust for factors associated with etoposide use. RESULTS: 168 patients with a median age of 49 [38, 59] were included. Forty-three (25.6%) patients presented with at least 1 microbiologically documented HAI throughout ICU stay. After adjustment, cumulative incidence of HAI was higher in patients receiving etoposide (p = 0.007), while survival was unaffected by etoposide status (p = 0.824). By multivariable analysis, etoposide treatment was associated with a higher incidence of HAIs (sHR 3.75 [1.05, 6.67]), whereas no association with survival (sHR 0.53 [0.20, 1.98]) was found. Other factors associated with increased mortality after adjustment included age, immunodepression, male sex, SOFA score > 13, and occurrence of HAI. CONCLUSIONS: In patients with sHS, etoposide treatment is independently associated with increased occurrence of HAIs, whereas no association with survival was found. Intensivists should be aware of increased infectious risk, to promptly detect and treat infections in this specific setting. Studies to assess benefits from prophylactic anti-infectious agents in this setting are warranted and the lack of benefit of etoposide on survival needs to be interpreted cautiously.

A Comprehensive Clinicopathologic and Molecular Study of 19 Primary Effusion Lymphomas in HIV-infected Patients.

Primary effusion lymphoma (PEL) is associated with human herpesvirus 8 and frequently with Epstein-Barr virus (EBV). We report here a single-center series of 19 human immunodeficiency virus-associated PELs, including 14 EBV+ and 5 EBV- PELs. The objectives were to describe the clinicopathologic features of PELs, with a focus on programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) expression, to search for genetic alterations by targeted deep sequencing analysis, and to compare the features between EBV+ and EBV- cases. All the patients were male, and the median age at diagnosis was 47 years old (interquartile range: 40 to 56 y). Reflecting the terminal B-cell differentiation, immunophenotypic profiles showed low expression levels of B-cell markers, including CD19 (0/19), CD20 (1/19), CD79a (0/19), PAX5 (1/19), BOB1 (3/19), and OCT2 (4/19), contrasting with a common expression of CD38 (10/19), CD138 (7/19), and IRF4/MUM1 (18/19). We observed a frequent aberrant expression of T-cell markers, especially CD3 (10/19), and less frequently CD2 (2/19), CD4 (3/19), CD5 (1/19), and CD8 (0/19). Only 2 cases were PD-L1 positive on tumor cells and none PD-1 positive. With respect to immune cells, 3 samples tested positive for PD-L1 and 5 for PD-1. Our 36-gene lymphopanel revealed 7 distinct variants in 5/10 PELs, with either a single or 2 mutations per sample: B2M (n=2), CD58 (n=1), EP300 (n=1), TNFAIP3 (n=1), ARID1A (n=1), and TP53 (n=1). Finally, we did not observe any major clinical, pathologic, or immunohistochemical differences between EBV+ and EBV- PELs and the outcome was similar (2-y overall survival probability of 61.9% [95% confidence interval, 31.2-82.1] vs. 60.0% [95% confidence interval, 12.6-88.2], respectively, P=0.62).

Leg-type form of idiopathic multicentric Castleman disease associated with severe lower extremity chronic venous/lymphatic disease.

Idiopathic multicentric Castleman disease (iMCD) is a lymphoproliferative disease of unknown etiology. Deciphering mechanisms involved in CD pathogenesis may help improving patients' care. Six cases of stereotyped sub-diaphragmatic iMCD affecting lower limb-draining areas and associated with severe and often ulcerative lower extremity chronic dermatological condition were identified in our cohort. Pathological examination revealed mixed or plasma-cell type MCD. In three patients, shotgun metagenomics failed to identify any pathogen in involved lymph nodes. Antibiotics had a suspensive effect while rituximab and tocilizumab failed to improve the condition. This novel entity requires a specific approach and exclusion of potentially harmful immunomodulation.

Pre-COVID-19 Immunity to Common Cold Human Coronaviruses Induces a Recall-Type IgG Response to SARS-CoV-2 Antigens Without Cross-Neutralisation.

The capacity of pre-existing immunity to human common coronaviruses (HCoV) to cross-protect against de novo COVID-19is yet unknown. In this work, we studied the sera of 175 COVID-19 patients, 76 healthy donors and 3 intravenous immunoglobulins (IVIG) batches. We found that most COVID-19 patients developed anti-SARS-CoV-2 IgG antibodies before IgM. Moreover, the capacity of their IgGs to react to beta-HCoV, was present in the early sera of most patients before the appearance of anti-SARS-CoV-2 IgG. This implied that a recall-type antibody response was generated. In comparison, the patients that mounted an anti-SARS-COV2 IgM response, prior to IgG responses had lower titres of anti-beta-HCoV IgG antibodies. This indicated that pre-existing immunity to beta-HCoV was conducive to the generation of memory type responses to SARS-COV-2. Finally, we also found that pre-COVID-19-era sera and IVIG cross-reacted with SARS-CoV-2 antigens without neutralising SARS-CoV-2 infectivity in vitro. Put together, these results indicate that whilst pre-existing immunity to HCoV is responsible for recall-type IgG responses to SARS-CoV-2, it does not lead to cross-protection against COVID-19.