Truncation of the constant domain drives amyloid formation by immunoglobulin light chains.

AL amyloidosis is a life-threatening disease caused by deposition of immunoglobulin light chains. While the mechanisms underlying light chains amyloidogenesis in vivo remain unclear, several studies have highlighted the role that tissue environment and structural amyloidogenicity of individual light chains have in the disease pathogenesis. AL natural deposits contain both full-length light chains and fragments encompassing the variable domain (VL) as well as different length segments of the constant region (CL), thus highlighting the relevance that proteolysis may have in the fibrillogenesis pathway. Here, we investigate the role of major truncated species of the disease-associated AL55 light chain that were previously identified in natural deposits. Specifically, we study structure, molecular dynamics, thermal stability, and capacity to form fibrils of a fragment containing both the VL and part of the CL (133-AL55), in comparison with the full-length protein and its variable domain alone, under shear stress and physiological conditions. Whereas the full-length light chain forms exclusively amorphous aggregates, both fragments generate fibrils, although, with different kinetics, aggregate structure, and interplay with the unfragmented protein. More specifically, the VL-CL 133-AL55 fragment entirely converts into amyloid fibrils microscopically and spectroscopically similar to their ex vivo counterpart and increases the amorphous aggregation of full-length AL55. Overall, our data support the idea that light chain structure and proteolysis are both relevant for amyloidogenesis in vivo and provide a novel biocompatible model of light chain fibrillogenesis suitable for future mechanistic studies.

Degradation versus fibrillogenesis, two alternative pathways modulated by seeds and glycosaminoglycans.

The mechanism that converts native human transthyretin into amyloid fibrils in vivo is still a debated and controversial issue. Commonly, non-physiological conditions of pH, temperature, or organic solvents are used in in vitro models of fibrillogenesis of globular proteins. Transthyretin amyloid formation can be achieved under physiological conditions through a mechano-enzymatic mechanism involving specific serine proteases such as trypsin or plasmin. Here, we investigate S52P and L111M transthyretin variants, both causing a severe form of systemic amyloidosis mostly targeting the heart at a relatively young age with heterogeneous phenotype among patients. Our studies on thermodynamics show that both proteins are significantly less stable than other amyloidogenic variants. However, despite a similar thermodynamic stability, L111M variant seems to have enhanced susceptibility to cleavage and a lower tendency to form fibrils than S52P in the presence of specific proteases and biomechanical forces. Heparin strongly enhances the fibrillogenic capacity of L111M transthyretin, but has no effect on the S52P variant. Fibrillar seeds similarly affect the fibrillogenesis of both proteins, with a stronger effect on the L111M variant. According to our model of mechano-enzymatic fibrillogenesis, both full-length and truncated monomers, released after the first cleavage, can enter into fibrillogenesis or degradation pathways. Our findings show that the kinetics of the two processes can be affected by several factors, such as intrinsic amyloidogenicity due to the specific mutations, environmental factors including heparin and fibrillar seeds that significantly accelerate the fibrillogenic pathway.

Bictegravir/Emtricitabine/Tenofovir Alafenamide Treatment: Efficacy and Tolerability in Clinical Practice.

Objective: Analysis of bictegravir/emtricitabine/tenofovir alafenamide (BFTAF) efficacy and safety in virologically suppressed people living with HIV (PLWH) in clinical practice. Patients and methods: The retrospective cohort study, which included adult treatment-experienced and virologically suppressed PLWH, switched to BFTAF from June 2019 to June 2021. Efficacy and safety were evaluated as virological failure (VF=2 consecutive HIV-RNA>50 copies/mL or a single HIV-RNA>400 copies/mL) and treatment failure (TF=VF or discontinuation for any reason) until data freezing (August 2022). Results: Of the 1040 PLWH included, 67.8% switched from elvitegravir/cobicistat/FTAF. VF occurred in 4.2% (n=44), with incidence rate of 1.63 per 1000 person-months of follow-up (PMFU) and probability at 24-30 months of 3.8%-4.0%, respectively. Out of the 44 VF, in 75% virological re-suppression was achieved while maintaining BFTAF. Discontinuation occurred in 15% after a median time of 13.5 months of follow-up, with an incidence rate of 5.67 per 1000 PMFU, and a probability at 24-30 months of 11.9%-15.3%, respectively. Main discontinuation reasons were simplification (51.3%) and toxicity (21.8%, involving CNS in half of cases). TF occurred in 18.6% with an incidence rate of 7.01 per 1000 PMFU after a median time of 13.6 observation months; probability at 24-30 months was 14.8%-18.4%, respectively. Conclusion: BFTAF has proven effective and well tolerated in clinical practice.

Mpox DNA clearance in semen over 6-month follow-up.

Sexual intercourse is a well-established way of transmission of mpox infection. However, it is still uncertain whether semen may represent a viral reservoir. The aim of the study was to evaluate the clearance of viral DNA in semen samples from individuals diagnosed with mpox infection over 6-month follow-up. This prospective, observational, single-center study was conducted at IRCCS San Raffaele Scientific Institute, Milan, Italy, between May and October 2022 in 140 individuals who attended Sexual Health Clinic and diagnosed with mpox infection. Semen samples were collected and analyzed by real-time polymerase chain reaction assays. The baseline collection was performed in 64 (46%) of 140 men diagnosed with mpox infection. The viral DNA was detected in 43 (67%) with median cycle threshold (Ct) 34 (interquartile range [IQR] 31-36). The research was repeated in 32 (74%) and viral DNA clearance was observed in all within 6 months in a median time of 10.5 days (IQR 7-33). Viral clearance occurred in all tested individuals, mostly within 2 weeks since the first positive test. These findings suggest a transient presence of viral DNA in semen and do not support the hypothesis of reservoir. More studies on mpox DNA detection in semen with viral culture and extended follow-up are needed.

Human wild-type and D76N ß2-microglobulin variants are significant proteotoxic and metabolic stressors for transgenic C. elegans.

ß2-microglobulin (ß2-m) is a plasma protein derived from physiological shedding of the class I major histocompatibility complex (MHCI), causing human systemic amyloidosis either due to persistently high concentrations of the wild-type (WT) protein in hemodialyzed patients, or in presence of mutations, such as D76N ß2-m, which favor protein deposition in the adulthood, despite normal plasma levels. Here we describe a new transgenic Caenorhabditis elegans (C. elegans) strain expressing human WT ß2-m at high concentrations, mimicking the condition that underlies dialysis-related amyloidosis (DRA) and we compare it to a previously established strain expressing the highly amyloidogenic D76N ß2-m at lower concentrations. Both strains exhibit behavioral defects, the severity of which correlates with ß2-m levels rather than with the presence of mutations, being more pronounced in WT ß2-m worms. ß2-m expression also has a deep impact on the nematodes' proteomic and metabolic profiles. Most significantly affected processes include protein degradation and stress response, amino acids metabolism, and bioenergetics. Molecular alterations are more pronounced in worms expressing WT ß2-m at high concentration compared to D76N ß2-m worms. Altogether, these data show that ß2-m is a proteotoxic protein in vivo also in its wild-type form, and that concentration plays a key role in modulating pathogenicity. Our transgenic nematodes recapitulate the distinctive features subtending DRA compared to hereditary ß2-m amyloidosis (high levels of non-mutated ß2-m vs. normal levels of variant ß2-m) and provide important clues on the molecular bases of these human diseases.

Viral blips and virologic failures following mpox vaccination with MVA-BN among people with HIV.

OBJECTIVES: The study aim was to evaluate whether mpox vaccination with modified vaccinia Ankara-Bavarian Nordic (MVA-BN) may be associated with viral blips or confirmed virologic failures (CVF) in people with HIV (PWH) receiving antiretroviral therapy and the associated factors. DESIGN: PWH who received MVA-BN, with HIV-RNA less than 50 copies/ml, and CD4 + lymphocytes at least 200 cells/µl in the 6 months prior to vaccination and at least 1 HIV-RNA determination within 3 months from vaccination. METHODS: The primary outcome was occurrence of viral blips (1 HIV-RNA ≥50 copies/ml) and CVF (1 HIV-RNA ≥1000 copies/ml or ≥2 consecutive HIV-RNA ≥50 copies/ml) following MVA-BN. Changes in CD4 + and CD4 + /CD8 + were secondary outcomes. Residual viremia was defined as detectable HIV-RNA less than 50 copies/ml. PWH already vaccinated against smallpox received single-dose MVA-BN. Mann--Whitney rank-sum test or chi-square/Fisher's test applied. RESULTS: Overall, 187 PWH were included: 147 received two doses of MVA-BN, 40 single-dose. Six viral blips [incidence rate = 1.59/100-person months of follow-up (PMFU), 95% confidence interval (95% CI) = 0.58-3.47], and three CVFs [incidence rate = 0.80/100-PMFU (95% CI = 0.16-2.33)] were observed. Two CVFs occurred at second dose with presence of detectable HIV-RNA following first one, with high compliance to antiretroviral therapy (ART). PWH with viral blips or CVFs had, prior to first vaccination, more frequently residual viremia [77% ( n  = 7) versus 35% ( n  = 62), P  = 0.01]. No differences in ART ( P  = 0.42) and number of MBA-BN doses ( P  = 0.40) was found. In two cases of CVFs, ART was changed; all VBs resolved within 1 month. CONCLUSION: Although rare, viral blips and CVFs following MVA-BN vaccination among PWH receiving ART were identified. Close monitoring of HIV-RNA during mpox vaccination should be encouraged.

High-dose anakinra in addition to standard of care including corticosteroids in patients with severe COVID-19 treated with non-invasive ventilation.

Management of COVID-19 patients experiencing persisting respiratory failure despite corticosteroids remains challenging. Data on high-dose intravenous anakinra (HD-ANK) in this context are lacking. We aimed to investigate the impact of HD-ANK on mortality in COVID-19 patients progressing to non-invasive ventilation (NIV) while receiving corticosteroids. We retrospectively analyzed the impact of HD-ANK on 28-day mortality in individuals hospitalized with COVID-19 necessitating NIV after corticosteroid initiation. A total of 256 patients were identified: 146 received standard-of-care only (SOC), and 110 received HD-ANK+SOC. The groups were well-balanced at baseline. In-hospital mortality at 28 days did not differ between the two groups. HD-ANK is not beneficial in patients with severe COVID-19 deteriorating despite corticosteroids.

Uncommon Haemorrhagic Cystitis of Infectious Origin: A Narrative Review for Urologists.

Purpose: Haemorrhagic cystitis may be due to different etiologies with infectious diseases representing an insidious cause to diagnose. The aim of this narrative review is to provide a comprehensive overview of less common but difficult-to-diagnose causes of infectious haemorrhagic cystitis of bacterial, mycobacterial, and parasitic origin, Moreover, we highlight possible diagnostic tools and currently available treatment options in order to give an updated tool for urologists to use in daily practice. Patients and Methods: The search engine PubMed was used to select peer-reviewed articles published from 1/Jan/2010 to 31/Aug/2022. Results: Bacteria, fungal, TB and schistosomiasis are uncommon causes of haemorrhagic cystitis burdened by high morbidity, especially if not promptly diagnosed. Conclusion: Because haemorrhagic cystitis ranges in severity from mild dysuria associated with pelvic discomfort to severe life-threatening haemorrhage, punctual diagnosis, and immediate treatment are essential to avoid further complications.

Treatment success of rescue regimens after dual therapy failure in people living with HIV in a real-life setting.

OBJECTIVES: Few data on management of two-drug regimen (2DR) failure in people living with HIV (PLWH) are available. METHODS: Retrospective study of treatment-experienced PLWH on a 2DR who experienced virological failure (VF) [two consecutive viral loads (VLs) ≥50 copies/mL, single VL ≥1000 copies/mL, or antiretroviral therapy (ART) switch after single VL ≥50 copies/mL with previous blips] or discontinuation for toxicity (baseline). Integrase strand transfer inhibitor (INSTI)-based [one INSTI plus one nucleoside reverse transcriptase inhibitor (NRTI) (n = 78) or one non-NRTI (n = 20)] or boosted protease inhibitor (PI/b)-based [one PI/b plus one NRTI (n = 116) or one INSTI (n = 12)] 2DRs were included. Probabilities of treatment success (TS), VF and discontinuation for any other cause of rescue regimens were estimated by Kaplan-Meier curves. A stepwise Cox model was performed to assess predictors of TS. RESULTS: Overall, 226 PLWH were evaluated: at baseline, 144 individuals discontinued 2DR for toxicity and 82 had VF [median viraemia 81 (63-212) copies/mL]; 171 switched therapy (49.7% to triple regimen, 40.9% to different 2DR), while 55 (exclusively with VF) maintained failing regimens. Probabilities of 12- and 24-month TS were 75.6% and 64.7%, respectively. Higher TS probabilities were observed in individuals who switched ART at 2DR failure (P = 0.003) and PLWH who discontinued 2DR for toxicity (P = 0.008). Therapy switch was the only predictor of TS (P = 0.002). CONCLUSIONS: Overall probability of rescue regimens' TS introduced after 2DR failure is good. Prompt ART switch after 2DR failure is advisable.

Viral Hepatitis and Human Papillomavirus Vaccination During HIV Pre-Exposure Prophylaxis: Factors Associated With Missed Vaccination.

BACKGROUND: We evaluated factors associated with lack of triple vaccination (hepatitis A virus [HAV], hepatitis B virus [HBV], and human papillomavirus [HPV]) among men who have sex with men using pre-exposure prophylaxis (PrEP). SETTING: PrEP users at the San Raffaele Scientific Institute, Italy, with ≥1 follow-up visit (May 2017-2022). METHODS: Participants were considered protected if (1) before PrEP access: positive serology (IgG-HAV+, hepatitis B surface antigen >10 mUI/mL) or vaccination history was recorded and (2) after starting PrEP: ≥1 dose of each vaccination was administered. Individuals were considered fully protected if they received the following before/during PrEP access: HAV vaccination/infection, HBV vaccination/infection, and HPV vaccination. χ 2 and Kruskal-Wallis tests were used to compare characteristics of those fully, partially, and not protected. Factors associated with the lack of triple vaccination were assessed by using multivariable logistic regression and classification tree analysis. RESULTS: Overall, 473 men who have sex with men were considered: 146 (31%) were fully protected, 231 (48%) partially, and 96 (20%) were not. Daily-based PrEP users (fully: 93, 63.7%; partially: 107, 46.3%; and not protected: 40, 41.7%; P = 0.001) and those with a sexually transmitted infection at the first visit (43, 29.5%; 55, 23.8%; 15, 15.6%; P = 0.048) were more frequently fully protected. At multivariable analysis, the odds of lack of triple vaccination was lower among daily-based users (adjusted odds ratio = 0.47, 95% confidence interval = 0.31-0.70, P < 0.001). Classification tree analysis showed that among daily-based users, with sexually transmitted infection prior and at the first PrEP visit, there was a lower chance of lack of triple vaccination ( P = 44%). CONCLUSIONS: Strategies targeting PrEP users at risk of missing HAV, HBV, and HPV vaccinations need to be implemented, focusing mostly on event-based users.

Human Monkeypox Experience in a Tertiary Level Hospital in Milan, Italy, between May and October 2022: Epidemiological Features and Clinical Characteristics.

BACKGROUND: Monkeypox virus (mpxv) started to spread to Europe and North America at the beginning of the current outbreak in May 2022, and the World Health Organization (WHO) declared Human Monkeypox (mpox) as a public health emergency of international concern (PHEIC) in July 2022. The aim of this observational analysis is to describe demographical data, symptoms presentation and clinical course till outcome of individuals diagnosed with mpox, between May and October 2022, at our open-access Sexual Health Clinic in IRCCS San Raffaele Hospital in Milan, Italy. METHODS: Among people who accessed our Sexual Health Clinic, we considered, as suspected diagnosis of mpox, individuals with consistent symptoms and epidemiological criteria. Following the physical examination, oropharyngeal, anal, genital and cutaneous swabs, plus plasma, urine and seminal fluid were collected as biological materials to detect mpxv DNA. We also performed a screening for sexually transmitted infections (STIs). RESULTS: Overall, 140 individuals with mpox were included in this study. Median age was 37 (interquartile, IQR 33, 43) years old. Males were 137 (98%) and men who have sex with men (MSM) were 134 (96%). As risk factors, we detected travels abroad in 35 (25%) individuals and close contact with mpox cases in 49 (35%). There were 66 (47%) people living with HIV (PLWH). Most frequent symptoms were fever (59%), lymphadenopathy (57%), cutaneous (77%), genital (42%), anal (34%) and oral (26%) lesions, proctitis (39%), sore throat (22%) and generalized rash (5%). At mpox diagnosis, we also observed N. gonorrhoeae in 18 (13%) cases, syphilis in 14 (10%) and C. trachomatis in 12 (9%). Two (1%) people received a concomitant diagnosis of HIV infection. We attended to 21 (15%) complications, with nine (6%) cases of hospitalization including six (IQR 3,7) median hospital days. Forty-five (32%) patients were treated with non-steroidal anti-inflammatory drugs (NSAIDs), 37 (26%) with antibiotics and eight (6%) with antiviral drugs. CONCLUSIONS: Similarly to other international cohorts, sexual transmission was most frequently present, and concomitant STIs were common. Symptoms were heterogenous, self-resolving and responsive to therapy. Hospitalization was necessary in few patients. There is uncertainty about the future development of mpox and further studies (e.g., potential disease reservoirs, other possible means of transmission, predictors of severe disease) are still needed.

The Protein Network in Subcutaneous Fat Biopsies from Patients with AL Amyloidosis: More Than Diagnosis?

AL amyloidosis is caused by the misfolding of immunoglobulin light chains leading to an impaired function of tissues and organs in which they accumulate. Due to the paucity of -omics profiles from undissected samples, few studies have addressed amyloid-related damage system wide. To fill this gap, we evaluated proteome changes in the abdominal subcutaneous adipose tissue of patients affected by the AL isotypes κ and λ. Through our retrospective analysis based on graph theory, we have herein deduced new insights representing a step forward from the pioneering proteomic investigations previously published by our group. ECM/cytoskeleton, oxidative stress and proteostasis were confirmed as leading processes. In this scenario, some proteins, including glutathione peroxidase 1 (GPX1), tubulins and the TRiC complex, were classified as biologically and topologically relevant. These and other results overlap with those already reported for other amyloidoses, supporting the hypothesis that amyloidogenic proteins could induce similar mechanisms independently of the main fibril precursor and of the target tissues/organs. Of course, further studies based on larger patient cohorts and different tissues/organs will be essential, which would be a key point that would allow for a more robust selection of the main molecular players and a more accurate correlation with clinical aspects.

Contactin-1 links autoimmune neuropathy and membranous glomerulonephritis.

Membranous glomerulonephritis (MGN) is a common cause of nephrotic syndrome in adults, mediated by glomerular antibody deposition to an increasing number of newly recognised antigens. Previous case reports have suggested an association between patients with anti-contactin-1 (CNTN1)-mediated neuropathies and MGN. In an observational study we investigated the pathobiology and extent of this potential cause of MGN by examining the association of antibodies against CNTN1 with the clinical features of a cohort of 468 patients with suspected immune-mediated neuropathies, 295 with idiopathic MGN, and 256 controls. Neuronal and glomerular binding of patient IgG, serum CNTN1 antibody and protein levels, as well as immune-complex deposition were determined. We identified 15 patients with immune-mediated neuropathy and concurrent nephrotic syndrome (biopsy proven MGN in 12/12), and 4 patients with isolated MGN from an idiopathic MGN cohort, all seropositive for IgG4 CNTN1 antibodies. CNTN1-containing immune complexes were found in the renal glomeruli of patients with CNTN1 antibodies, but not in control kidneys. CNTN1 peptides were identified in glomeruli by mass spectroscopy. CNTN1 seropositive patients were largely resistant to first-line neuropathy treatments but achieved a good outcome with escalation therapies. Neurological and renal function improved in parallel with suppressed antibody titres. The reason for isolated MGN without clinical neuropathy is unclear. We show that CNTN1, found in peripheral nerves and kidney glomeruli, is a common target for autoantibody-mediated pathology and may account for between 1 and 2% of idiopathic MGN cases. Greater awareness of this cross-system syndrome should facilitate earlier diagnosis and more timely use of effective treatment.

HIV viral load monitoring during monkeypox virus infection among people with HIV.

OBJECTIVES: Aims of this study were to assess the characteristics of Mpox among people with HIV (PWH) and describe the change of some immune-virological parameters during Mpox virus infection. DESIGN: Case series of PWH diagnosed with Mpox between May and July 2022 at the Infectious Diseases Unit of San Raffaele Scientific Institute, Milan, Italy. METHODS: Real-time PCR was used to detect Mpox virus on oropharyngeal, cutaneous, genital and rectal swabs, plasma, seminal fluids, and urines. The values of the CD4 + lymphocytes and HIV-RNA were assessed both at Mpox diagnosis and after Mpox virological clearance and were compared to those prior to Mpox. The relationship between the symptoms clinical duration of Mpox and the CD4 + cell count at diagnosis was assessed with Spearman's correlation coefficient. RESULTS: Overall, 28 PWH on antiretroviral therapy with Mpox were evaluated. HIV-RNA did not substantially change at Mpox infection with respect to previous virological profile ( P  = 0.721). However, at time of Mpox diagnosis, we observed a detectable HIV-RNA (196 copies/ml) in one individual previously undetectable (HIV-RNA < 20 copies/ml) and an increase to 1.220 copies/ml in a previously viremic subject (HIV-RNA = 263 copies/ml). No significant differences in CD4 + cell count were found before and at time of Mpox diagnosis ( P  = 0.151) and a higher CD4 + cell count at Mpox diagnosis was marginally related to a lower duration of Mpox symptoms ( r  = -0.341, P  = 0.068). CONCLUSIONS: Among PWH, we advise monitoring HIV viral load at Mpox diagnosis and during follow-up, as well as providing counseling on the results, due to the important individual and community implications.