Complement Fractions Research Articles

Natural history of chronic idiopathic neutropenia of the adult

Chronic idiopathic neutropenia (CIN) is a rare benign condition caused by an immune attack against neutrophils, either primary or in the context of other autoimmune conditions, lymphoproliferative syndromes, and inborn errors of immunity. In this single-center prospective study, 131 adult CIN patients were enrolled (median age 55 years, range: 20–93). At baseline, 56% had anti-neutrophil autoantibodies and 31% had autoimmune comorbidities. Over a median 3-year follow-up, the rate of grade ≥ 2 infections was 42%, with 10% grade ≥ 3, irrespective of neutrophil counts, demographics, and anti-neutrophil antibodies positivity, and G-CSF was used in 6 patients only. No malignant evolution nor deaths were observed. Bone marrow evaluation showed a large granular lymphocyte (LGL) infiltrate in 52%, mostly polyclonal, and hypocellularity in 31% of cases. Immune-histochemistry highlighted deposits of IgG, IgM, and complement fractions C3 and C4d in most cases. Interestingly, 19% of tested patients displayed somatic mutations of myeloid genes with an association with age. In conclusion, adult CIN appears to be a benign condition without life-threatening infections, yet deserving an extensive hematologic evaluation including bone marrow assessment to inform the differential diagnosis.

#1390 Differences in the detection of anti-HLA antibodies between two single antigen bead methods in kidney transplantation patients

Abstract Background and Aims Two semiquantitative single-antigen bead (SAB) methods are currently available for the detection of anti-HLA antibodies and the estimation of their activity, depending on complement binding. However, data on accordance of the two methods on specificities detection and their reactivity evaluation are scarce. The purpose of this study is to compare the two methods in terms of anti-HLA antibodies specificities detection and of their complement binding capacity Method Sera from 97 patients with a positive Panel Reactive Antibody Test (>5%) was tested by two SAB methods, Immucor (IC) and One-lambda (OL), for class I and II anti-HLA antibody specificities and their ability to bind complement. The patients were either on a waiting list for kidney transplantation or transplanted patients tested routinely or after a clinical event. Statistical analysis of the results and comparison of the two methods followed. Results OL detected more class I positive specificities per patient [25 (9-34) vs. 18 (7-28) with IC, p < 0.001], while the two methods showed no difference in class II anti-HLA antibodies. IC detected 1608 out of 8148 and 1136 out of 7275 totally examined, positive anti-HLA class I and II antibody specificities respectively, with a median mean fluorescence intensity (MFI) of 4195 (1995-11272) and 6706 (2647-13184) respectively. Similarly, OL detected 1942/8148 and 1247/7275 positive specificities of anti-HLA class I and II antibodies respectively, with MFI 6185 (2855-12099) and 9498 (3630-17702)] respectively. In the IC method, 428/1608 [MFI 13900 (9540-17999)] and 409/1136 [MFI 11832 (7128-16531)] positive class I and II specificities, respectively, bound the C3d fraction of complement. Similarly, OL detected 485/1942 [MFI 15452 (9369-23095)] and 298/1247 [MFI 18852 (14415-24707)] class I and II specificities respectively that bound the C1q fraction of complement. In the analysis of the specificities that were positive by both methods, MFI showed a strong positive linear correlation between the two methods (r = 0.61, p < 0.001 and r = 0.54, p = 0.001 for classes I and II respectively). Accordingly, data were analyzed with Principal Components Analysis, in which negative results were also included. In the projection of the plane defined by the first two principal components the vector corresponding to the IC method for class I antibodies was congruent with the vectors of the complement binding detection methods, C3d and C1q. In contrast, the OL vector was nearly perpendicular to the other vectors, indicating the existence of non-complement-binding specificities that are not detected by IC. A similar picture was found for antibodies against HLA class II (Figure). Conclusion OL was more sensitive for detecting class I and II anti-HLA antibodies despite the fact that there was no difference in the number of class II specificities per patient. However, the additional specificities detected by OL, potentially do not bind complement. The MFI of the complement binding specificities were higher in both methods. The two methods were equivalent in detecting complement-binding class I specificities, however the C3d IC method was more sensitive in detecting complement-binding class II anti-HLA antibodies.

#2633 Navigating complexity: a case report of chronic kidney disease with renal stone unravelling a rare metabolic disorder

Abstract Clinical Presentation A 48-year-old female of Asian heritage was referred for renal assessment after experiencing recurrent acute kidney injury (AKI) with incomplete recovery between episodes. This was initially attributed to dehydration and interstitial nephritis stemming from long-standing vomiting, a manifestation of gastroscopy-proven erosive gastritis, compounded by the use of high-dose proton pump inhibitors (PPI). Her relevant medical history is of right nephrectomy in 1996 due to recurrent urinary tract infections (UTIs), and previous left renal calculus in 2019 with no visible stones on further CT imaging. Despite living with a single kidney, her baseline eGFR had been normal prior to referral. While unaware of her mother's medical history, her father was recently diagnosed with kidney disease (no clear history) and her sister Wilson's disease. A kidney biopsy was undertaken given the incomplete eGFR recovery between episodes. The biopsy revealed adequate tissue including 24 glomeruli, no significant glomerular pathology was seen. There is 65% tubulointerstitial atrophy and fibrosis, and yellow to red-brown-tinged crystals within tubular lumina and epithelial cells, prompting a histiocytic reaction. These crystals were birefringent under polarized light and did not stain with Perl's and Von Kossa stain (Fig. 1a-d). Immunofluorescence was negative for all immunoglobulins and complement fractions. No immune complex/substructure deposits were seen in the glomeruli on electron microscopy. Blood tests assessing APRT activity indicated values within the carrier range (Table 1). The patient and her family have been referred for a comprehensive genetic testing for APRT genetic mutations. Treatment with Allopurinol 300 mg daily resulted in a sustained eGFR improvement from 19 to 33 ml/min/1.73m2 at 6 months after initiation (Fig. 1). Discussion Adenine phosphoribosyl transferase (APRT) deficiency, also known as Dihydroxyadenineuria, is a rare autosomal recessive inherited condition leading to kidney stones. If left untreated, up to 25% progress to end-stage kidney disease (ESKD). Although inherited, half of patient present in adulthood and may do so with laboratory findings of CKD rather than specifically with stones [1]. This case highlights the significance of precise diagnosis in calculi-related kidney diseases. Early intervention can alter the trajectory of specific conditions, averting progression to ESKD. This case is unusual in being a carrier of an autosomal recessive condition presenting with full manifestations of the disease. Patient Consent The patient has given verbal, documented consent for case publication. Acknowledgment We thank all renal and pathology staff members at Salford Care Organisation who contributed to the diagnosis and management of our case.

Efficacy and safety of the type I interferon receptor inhibitor anifrolumab in patients with systemic lupus erythematosus (results of a 6-month study)

Objective: to evaluate the efficacy and safety of the type I interferon (IFN) receptor inhibitor anifrolumab (AFM, Safnelo®) in patients with systemic lupus erythematosus (SLE) in real-life clinical practice over an observation period of 6 months.Material and methods. The prospective 6-month study included 21 patients with SLE fulfilling the 2012 SLICC criteria, predominantly women (n=17,81%), median age – 31 [27; 46] years, disease duration – 9 [6.0; 11.0] years. Standard laboratory values and immunological markers of SLE were examined in all patients. The SLEDAI-2K index was used to determine the activity of SLE, and the severity of the mucocutaneous syndrome was assessed using the Cutaneous Lupus Disease Area and Severity Index (CLASI) index. Organ damage was assessed using the SLICC/ACR Damage Index (DI). After 6 months, the achievement of low activity was assessed according to the Lupus Low Disease Activity State (LLDAS) indexResults and discussion. At the time of inclusion in the study, the mean SLEDAI-2K activity index for the group was 8 [6.0; 10.0] points, the median CLASI index – 8.6±8.2 points, 81% of patients had skin and mucosal lesions, 66% had non-erosive polyarthritis, and high immunological activity was observed in all cases. Various irreversible organ damage was observed in 86 of patients. The average DI was 2.2±1.5 points. At the start of AFM therapy, all patients received glucocorticoids (GCs) at a mean dose of 10.7±5.6 mg/day, 52% of patients received a dose above 10 mg/day, 76% of patients continued to take hydroxychloroquine, and 33% of patients took immunosuppressants. Significant positive dynamics were observed with AFM therapy. The average CLASI index for the group after 3 months of treatment was 1.2±4.1 points, after 6 months – 0.3±1.2 points (p<0.0001). The SLEDAI-2K index fell significantly in the group on average from 8 [6.0; 10.0] to 2 [2.0; 4.0] points from the 3rd month of treatment (p<0.0001) and remained at the same level after 6 months. At month 6 of treatment, 13 (62%) of 21 patients met the LLDAS criteria for low disease activity. After the 3rd month of treatment, a significant decrease in antibodies against dsDNA was observed, which persisted for 6 months after the start of treatment. In the group as a whole, there were no significant changes in complement fractions values during the observation period. There was no increase in irreversible organ damage (DI – mean 2.2±1.5 points). The mean daily dose of GCs was significantly reduced from 10.7±5.6 mg/day to 7.5±4.0 mg/day (p<0.01) by the 3rd month and to 5.2±2.1 (p<0.001) by the 6th month of treatment. No infusion reactions were observed in any case. Adverse events occurred in 9 (42%) out of 21 patients, mainly herpes infections of varying severity, mainly after the 1st to 3rd infusions. In one case, severe herpes zoster was observed, so the drug was discontinued.Conclusion. At a dose of 300 mg intravenously monthly AFM is a highly effective drug with a relatively good safety profile in patients with active SLE in whom autoantibodies are present and who do not respond adequately to standard therapy.

Reduced expressions of apoptosis-related proteins TRAIL, Bcl-2, and TNFR1 in NK cells of juvenile-onset systemic lupus erythematosus patients: relations with disease activity, nephritis, and neuropsychiatric involvement.

Lupus pathogenesis is mainly ascribed to increased production and/or impaired clearance of dead cell debris. Although self-reactive T and B lymphocytes are critically linked to lupus development, neutrophils, monocytes, and natural killer (NK) cells have also been implicated. This study assessed apoptosis-related protein expressions in NK cells of patients with juvenile-onset systemic lupus erythematosus (jSLE) and relations to disease activity parameters, nephritis, and neuropsychiatric involvement. Thirty-six patients with jSLE, 13 juvenile dermatomyositis (JDM) inflammatory controls, and nine healthy controls had Fas, FasL, TRAIL, TNFR1, Bcl-2, Bax, Bim, and caspase-3 expressions in NK cells (CD3-CD16+CD56+) simultaneously determined by flow cytometry. Disease activity parameters included Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score, erythrocyte sedimentation rate, C-reactive protein level, anti-double strain DNA antibody level, complement fractions C3 and C4 levels. Patients with jSLE had a profile of significantly reduced expression of TRAIL, Bcl-2, and TNFR1 proteins in NK cells when compared to healthy controls. Similar profile was observed in patients with jSLE with active disease, positive anti-dsDNA, nephritis, and without neuropsychiatric involvement. Patients with jSLE with positive anti-dsDNA also had reduced expression of Bax in NK cells when compared healthy controls and to those with negative anti-dsDNA. Yet, patients with jSLE with negative anti-dsDNA had reduced mean fluorescence intensity (MFI) of Bim in NK cells compared to healthy controls. Patients with jSLE with nephritis also had reduced MFI of Fas in NK cells when compared to those without nephritis. In addition, in patients with jSLE, the proportion of FasL-expressing NK cells directly correlated with the SLEDAI-2K score (rs = 0.6, p = 0.002) and inversely correlated with the C3 levels (rs = -0.5, p = 0.007). Moreover, patients with jSLE had increased NK cell percentage and caspase-3 protein expression in NK cells when compared to JDM controls. This study extends to NK cells an altered profile of TRAIL, Bcl-2, TNFR1, Fas, FasL, Bax, Bim, and caspase-3 proteins in patients with jSLE, particularly in those with active disease, positive anti-dsDNA, nephritis, and without neuropsychiatric involvement. This change in apoptosis-related protein expressions may contribute to the defective functions of NK cells and, consequently, to lupus development. The full clarification of the role of NK cells in jSLE pathogenesis may pave the way for new therapies like those of NK cell-based.

A prospective observational study correlating possible novel biomarkers with disease severity and antihistamine response in chronic spontaneous urticaria.

Role of complement fraction 5a (C5a), interleukin (IL)-9, and apolipoprotein (apo) A-IV as biomarkers of disease severity and antihistamine response in chronic spontaneous urticaria (CSU) remains elusive. To identify the role of C5a, IL-9, and apo A-IV as potential biomarkers in predicting disease severity and antihistamine response in CSU patients. This was a prospective observational study of 95 patients and 42 controls. Serum analysis of C5a, IL-9, and apo A-IV was done using enyzme linked immunosorbent assay kits. Also, serum IgE and anti-thyroid peroxidase (TPO) levels were assessed in all patients. All patients were started on oral levocetirizine 5 mg at baseline and dose was titrated upwards to maximum of 20 mg based on response. Patients were categorized into antihistamine responders or nonresponders as per their disease response. Serological markers, serum IgE, and anti-TPO were correlated with baseline disease severity and antihistamine response. C5a levels were significantly higher in cases as compared to controls (P = 0.004). Significantly higher IL-9 levels were observed in antihistamine responders than nonresponders (P = 0.008). Baseline urticaria severity demonstrated a statistically significant positive and negative correlations with IL-9 (ρ = 0.277, P = 0.007) and apo A-IV (ρ = -0.271, P = 0.008) levels, respectively. Levels of serum IgE (P = 0.031) and anti-TPO (P = 0.039) were significantly higher in antihistamine nonresponders compared to responders. IL-9 and apo A-IV might be potential novel biomarkers to predict urticaria severity. Higher IL-9 might be a predictor of antihistamine response. Elevated anti-TPO and serum IgE might predict poor antihistamine response.

Increased level of C3 in synovial fluid in patients with activated osteoarthritis as a diagnostic and therapeutic target – pilot group of patients from the Rheumatology Department at UMHAT Burgas

The clinical course of osteoarthritis (OA) indicates the role of low-grade synovitis as the main driver of the degenerative process. Components of the extracellular matrix, fibronectin isoforms, and fragments of hyaluronic acid are presumed ligands for DAMPs (particularly TLR). Complement fractions bind to the corresponding receptors on the cell membranes of chondrocytes and synoviocytes through TLR. Does the complement cascade play a role only as a clearing system and/or a leading pathogenetic factor in activated OA? The aim of this study is to answer this question. The study included 50 patients with activated OA of the knee joint. We examined the levels of C3 and C4 complement fractions in the blood plasma and synovial fluid. We found that the values of these proteins in synovial fluid were on average 34.90% for C3 and 30.97% for C4 of their values in blood plasma, with a generally accepted norm of 10% for complement levels in a healthy joint. The observation regarding the strength of correlation between the above results and the radiological stage confirmed a stronger correlation of the obtained results in the earlier stages of the disease when the activity of the repair processes is more pronounced. In this way, we objectified the pathogenetic role of complement in the arthritic process, as well as its role in clearing the joint space from degradation products. The question arises whether pharmacological intervention to balance complement activation could represent a future therapeutic strategy in the treatment of OA and prevent its progression.

#6249 UTILITY OF REPEAT KIDNEY BIOPSY IN LUPUS NEPHRITIS PATIENTS: A SINGLE CENTRE EXPERIENCE

Abstract Background and Aims Given the acummulating evidence of discrepancies between the clinical features and histological lesions in lupus nephritis patients, there is an increasing need for a histology-guided approach in order to optimise the management of these patients. Method 13 adult patients with a diagnosis of systemic lupus erythematosus and biopsy-proven lupus nephritis, followed up in the Nephrology Department of Fundeni Clinical Institute in Bucharest, Romania, from 2015 to 2022, which had undergone a repeat per-protocol biopsy at 6 months were included in this retrospective, single-centre study. The objectives of the study were to determine the evolution of the clinical and histological parameters at first and at 6-months repeat-biopsy, their possible associations and their relationship with the primary efficacy renal response (PERR) at 12 months.The National Institutes of Health activity index (AI) and chronicity index (CI) scores were assessed in all biopsies. PERR was defined as proteinuria ≤ 0.7 g/24 h and eGFR ≥60 ml/min/1.73 m2. Results The median (IQR) follow-up was 20 (13.5-34) months. 53.8% were class IV lupus nephritis at the first biopsy. Repeat biopsies were performed after a median time (IQR) of 6 (6-9) months. The majority of the patients recieved cyclophosphamide and corticosteroids as induction regimen (69.2%) and mycophenolate mofetil and corticosteroids as maintenance regimen (92.3%). PERR was achieved in 61.5% of cases at 12 months. Proteinuria (g/24 h) decreased from the median value (IQR) of 2,3 (1,55-4,3) to 0,4 (0,2-3,1) at biopsy 2 (p 0,02), hematuria (red blood cells/μl) decreased from 33 (11.5-178,5) to 10 (1,75-62) at biopsy 2 (p 0,017) and serum creatinine decreased from 1,18 (0,81-1,48) to 0,9 (0,73-1,07) at biopsy 2 (p <0,001). Serum C3 (mg/dl) increased from 56 (41-76,5) to 103 (84-126) (p <0,001), whereas serum C4 (mg/dl) increased from 10 (4-19) to 22 (11-31) (p <0,001). AI scores decreased from 10 (8,5-13,5) to 3 (2,5-7) (p <0,001) and CI scores increased from 2 (2-3) to 3 (3-5,5) (p <0,001). At repeat biopsy, CI increased in 8 patients (61,5%). Its increase was not predicted by baseline or at the moment of repeat biopsy values of activity and chronicity indices, renal function, hematuria, proteinuria and complement fractions. The type of induction regimen used did not protect against CI increase (p 0,506). The baseline value – median (IQR) of AI (9 (6,5-14,5) vs 10,5 (9-13,75), p 0,596), CI (2 (1,5-2,5) vs 3 (2-4,5), p 0,127), serum creatinine (mg/dl)(1,18 (0,96-1,66) vs 1,03 (0,75-1,36), p 0,316), hematuria (red blood cells/μl) (78 (10,9-1086) vs 29 (7,25-111,5), p 0,622) and complement fractions C3 (mg/dl) (74 (40-104) vs 48,5 (41-71,5), p 0,33) and C4 (mg/dl) (18 (6-23,5) vs 8 (3-15,75), p 0,36) were not associated with the PERR at 12 months. The median value (IQR) of AI (3 (2-9) vs 3,5 (2,25-7), p 0,943) and CI (3 (2,5-5) vs 5 (3-5,75), p 0,42), hematuria (red blood cells/μl)(26(2,25-85,5) vs 6,5 (1,4-48,25), p 0,35) and serum creatinine (mg/dl) (1,18 (0,89-1,12) vs 0,77 (0,7-0,9), p 0,13) at the second biopsy were also not associated with the PERR at 12 months. Proteinuria at baseline (g/24 h) (4,6 (2,37-8,1) vs 1,85 (1,16-2,6), p 0,019) and proteinuria at repeat biopsy (g/24 h) (4,6 (1,45-6,1) vs 0,23 (0,17-0,36), p 0,002) were associated with PERR at 12 months. Lower complement fraction C3 at the second biopsy (mg/dl) (123 (104-142) vs 88,5 (74,75-106,5), p 0,036) was associated with the PERR at 12 months and lower serum C4 at the second biopsy (mg/dl) (26 (21-34,5) vs 16 (7-29), p 0,082), had a trend to associate with the PERR at 12 months. Conclusion At the second biopsy, the chronicity index increase was not predicted by baseline or at the moment of repeat biopsy values of activity and chronicity indices, renal function, hematuria, proteinuria or the values of complement fractions. The type of induction regimen used did not protect against chronicity index increase. Proteinuria at baseline and at repeat biopsy was associated with PERR at 12 months. Lower complement fraction C3 at the second biopsy was associated with the PERR at 12 months and lower serum C4 at the second biopsy had a trend to associate with the PERR at 12 months.

Comparative Analysis of Hematological and Immunological Parameters in Patients with Primary Sjögren's Syndrome and Peripheral Neuropathy.

Primary Sjögren syndrome (pSS) is a multisystem disorder of autoimmune etiology, frequently involving peripheral nerves. Early detection of peripheral neuropathy (PN) manifestations might improve prognosis and disease control. The purpose of the study was to evaluate the predictive potential of hematological and immunological parameters associated with PN development in pSS patients. This single-center retrospective study included patients with pSS who were divided into two groups, according to the occurrence of neurological manifestations throughout the follow-up period. From the total of 121 pSS patients included in the study, 31 (25.61%) developed neurological manifestations (PN+ group) during the follow-up period. At the moment of pSS diagnosis, 80.64% of PN+ patients exhibited increased disease activity, with ESSDAI scores above 14 (p = 0.001), and significantly higher values for VASp score (p = 0.001), with a mean value of 4.90 ± 2.45, compared to 1.27 ± 1.32 in the PN- group. The hematological assessment at the moment of pSS diagnosis revealed that neutrophils and neutrophil-to-lymphocyte ratio (NLR) were significantly higher in the PN+ group (p = 0.001), while lymphocytes, monocytes and monocyte-to-lymphocyte ratio (MLR) were significantly lower (p = 0.025, p = 0.13 and p = 0.003, respectively). Immuno-inflammatory parameters-gammaglobulins, complement fractions C3, C4, total proteins and vitamin D were significantly lower in the PN+ patients' group. In multivariate analysis, the independent predictive character for PN development in pSS patients was confirmed for NLR (95% CI 0.033 to 0.263, p = 0.012), MLR (95% CI -1.289 to -0.194, p = 0.008), gammaglobulins (95% CI -0.426 to -0.088, p < 0.003), complement fraction C4 (95% CI -0.018 to -0.001, p < 0.030) and vitamin D (95% CI -0.017 to -0.003, p < 0.009). Readily available and frequently used hematological and immunological markers, such as NLR, MLR, gammaglobulins, C4 and vitamin D could be helpful in predicting the neurological involvement in pSS patients. These biological parameters might become useful tools for clinicians to monitor disease progression and identify potentially severe extraglandular manifestations in pSS patients.

Increased Complement Activation in Systemic Sclerosis Patients with Skin and Lung Fibrosis.

Introduction: The involvement of complement system in the phenotypic expression of systemic sclerosis (SSc) is a debated topic. We aimed to assay complement fractions in SSc patients and to correlate their levels with the clinical course of disease. Key points: 1. CH50 is increased in SSc patients compared to HC; 2. Serum C2 levels are increased in SSc patients compared to HC; 3. CH50 may represent a biomarker of skin and lung fibrosis severity in SSc patients. Method: Complement hemolysis 50% (CH50), C2, C3 and C4 levels have been assessed in 85 SSc patients and 47 healthy controls (HC). Results: SSc patients displayed a statistically significant higher value of CH50 [76.3 U/mL (IQR 65.8–89.4 U/mL) vs. 29.6 U/mL (IQR 24.7–34 U/mL); p < 0.0001] and of C2 [26.1 mg/L (IQR 24.1–32.1 mg/L) vs. 22.7 mg/L (IQR 20.6–24.4 mg/L); p < 0.0001] if compared to HC. Patients with diffuse cutaneous SSc (dcSSc) had higher levels of CH50 than patients with limited cutaneous SSc (lcSSc) [83.6 U/mL (IQR 72.3–102.7 U/mL) vs. 71.3 U/mL (IQR 63.7–83.6 U/mL); p = 0.003]. SSc patients with interstitial lung disease (ILD) had higher CH50 levels if compared to SSc patients without ILD [79.6 U/mL (IQR 68.3–97.4 U/mL) vs. 69.7 U/mL (54.6–85.7 U/mL); p = 0.042]. A positive linear correlation existed between CH50 and the modified Rodnan Skin Score (mRSS) (r = 0.285, p = 0.008) and disease severity scale (DSS) (r = 0.285, p = 0.005); a negative linear correlation was demonstrated between CH50 and the diffusing capacity of carbon monoxide (DLco) (r = −0.252, p = 0.012). In multiple linear regression analysis, only DSS was significant (p = 0.01, beta coefficient 2.446). Conclusions: Our results show an increment of CH50 and serum C2 levels in SSc patients in comparison to HC; we retain that CH50 may represent a biomarker of disease severity and of skin and lung fibrosis in these patients.

The association between lupus serology and disease outcomes: A systematic literature review to inform the treat-to-target approach in systemic lupus erythematosus.

Serological markers such as anti-double stranded (ds)DNA antibodies and complement fractions C3/C4, are integral components of disease activity assessment in patients with systemic lupus erythematosus (SLE). However, it remains uncertain whether treatment should aim at restoration of serological abnormalities. To analyze and critically appraise the literature on the prognostic impact of active lupus serology despite clinical disease quiescence. A systematic literature review was performed in PubMed and EMBASE using the PICOT(S) (population, index, comparator, outcome(s), timing, setting) system to identify studies evaluating the association of serum anti-dsDNA, C3 and C4 levels assessed at the time of clinical remission or during the disease course, against the risk for impending flares and organ damage. Risk of bias was determined by the Quality in Prognosis Studies and ROB2 tools for observational and randomized controlled studies, respectively. Fifty-three studies were eligible, the majority having moderate (70.6%) or high (11.8%) risk of bias and not adequately controlling for possible confounders. C3 hypocomplementemia during stable/inactive disease was associated with increased risk (2.0 to 3.8-fold) for subsequent flare in three out of seven relevant studies. Three out of four studies reported a significant effect of C4 hypocomplementemia on flare risk, including one study in lupus nephritis (likelihood ratio-positive 12.0). An increased incidence of flares (2.0 to 2.8-fold) was reported in 11 out of 16 studies assessing the prognostic effect of high anti-dsDNA, and similarly, the majority of studies yielded significant relationships with renal flares. Six studies examined the effect of combined (rather than individual) serological activity, confirming the increased risk (2.0 to 2.7-fold) for relapses. No consistent association was found with organ damage. Notwithstanding the heterogeneity and risk of bias, existing evidence indicates a modest association between abnormal serology and risk for flare in patients with stable/inactive SLE. These findings provide limited support for inclusion of serology in the treat-to-target approach but rationalize to further investigate their prognostic implications especially in lupus nephritis.

MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL SIGNS OF PLACENTAL DISORDERS OF WOMEN AFTER SYPHILITIC INFECTION.

The aim: To define morphological and immunohistochemical signs of placental disorders of women after syphilitic infection. Materials and methods: The prospective study of 60 pregnant women with history of syphilitic infection (main group) and 57 pregnant patients without syphilis (control group) was conducted. The morphological and immunohistochemical study of the afterbirth was performed. Results: In the placentas of women of the main group the following phenomena were found out: circulatory disorders in the form of hemorrhages into the intervillous space and the stroma of villi; accumulation of fibrinoid around villi with dystrophically altered stroma, compensatory-adaptive reactions resulted in hyperplasia of terminal villi and vessels in them, which provoked narrowing of the intervillous space and disruption of blood supply in it. Pathogenic immune complexes containing Ig G, M and C3 of the complement fraction were located in the central part of the placenta - 45.00% of cases, 16.67% - in the regional, 8.33% - in both parts. Immune complexes with Ig M content occurred in 38.33% of cases. The content of pathogenic immune complexes was the most concentrated in the placentas of women with latent forms and secondary recurrent syphilis - 60.00% of cases. Conclusions: changes in morphohistological and immunohistochemical examination of the placenta of this group of women confirmed the detrimental effect of syphilitic infection in the anamnesis on the structure of placenta during the next pregnancies.

Autoimmune manifestations of visceral leishmaniasis in Chinese patients.

Visceral leishmaniasis (VL) is a rare, parasitic infection with distinctive features that may mimic autoimmune diseases. In this study, we report on the laboratory autoimmune manifestations of VL in Chinese patients. Twenty-seven patients who were hospitalized with VL were included in this retrospective study. Routine blood and biochemical tests were conducted, and a variety of autoimmune antibodies and complement fractions were detected. Continuous variables are expressed as means ± standard deviations, and categorical data are expressed as a number (percentage). Missing data were not included for statistical analysis. Data were analyzed with SPSS v. 13.0 statistical software. All patients had cytopenia (82% with pancytopenia) and hepatosplenomegaly, and 25 (93%) patients also suffered from fever. The prevalence of autoantibodies (number of patients with antibody detected/total number of patients tested for the antibody) for each antibody tested was as follows: antinuclear antibodies (ANA; 18/22, 82%), anti-neutrophil cytoplasmic antibodies (ANCA; 4/5, 80%), anti-mitochondrial M2 antibodies (AMA-M2; 1/6, 17%), anti-liver cytosol specific type 1 antibodies (anti-LC1; 1/6, 17%), anti-liver/kidney microsomal type 1 antibodies (anti-LKM1; 1/6, 17%), anti-centromere protein-B antibodies (anti-CENP-B; 4/21, 19%), anti-Sjögren's syndrome type A antibodies (anti-SSA; 2/21, 10%), anti-Sjögren's syndrome type B antibodies (anti-SSB; 1/21, 5%), anti-Jo-1 antibodies (1/21, 5%), anti-double-stranded DNA antibodies (anti-dsDNA; 1/25, 4%), direct antiglobulin test (direct Coombs; 6/6, 100%), and rheumatoid factor (RF; 3/11, 27%). Increased serum C-reactive protein (CRP) was found in 14 (100%) patients. Of the 19 patients tested for serum IgG, 17 patients (89%) were found with increased IgG levels, while complement 3 protein (C3) and complement 4 protein (C4) levels were not decreased in any of the 19 patients. Of note, in one patient followed up 1 month after therapy, only ANA was still present, and all the other laboratory autoimmune manifestations had disappeared. VL infection associated with laboratory autoimmune manifestations is common. This may lead to patients with VL being misdiagnosed as having an autoimmune disorder. An obligatory differential diagnosis that considers VL should be undertaken for patients diagnosed with systemic lupus erythematosus (SLE), especially in endemic areas, is necessary.

Low level of complement factor H increases the risk of cancer-related death in patients with small-cell lung cancer

IntroductionPulmonary cancer is a kind of deeply invasive tumour which is difficult to treat, and its mortality rate is high. Previous research has shown that activation of complement could contribute...

Bartonella and Coxiella infections presenting as systemic vasculitis: case series and review of literature

Coxiella and Bartonella spp. display particular tropism for endothelial or endocardial tissues and an abnormal host response to infections with induced autoimmunity. We aimed, through a case series combined with a comprehensive literature review, to outline characteristics of Coxiella and Bartonella infections presenting as systemic vasculitis. We retrospectively included cases of definite Coxiella and Bartonella infections presenting with vasculitis features and performed a comprehensive literature review. Six cases of Bartonella infections were added to 18 cases from literature review. Causative pathogens were mainly B. henselae. Bartonella infection mimicked ANCA-associated vasculitis in 83% with PR3-ANCA and presented as cryoglobulinaemic vasculitis in 8%. GN was present in 92%, and 88% had endocarditis. Complement fractions were low in 82% and rheumatoid factor positive in 85%. Kidney biopsies showed cell proliferation, mostly crescentic, with pauci-immune GN in 29%. Outcome was favourable, with the use of antibiotics alone in one-third. Five cases of Coxiella infections were added to 16 from literature review. Sixteen had small-vessel vasculitides, mainly cryoglobulinaemia vasculitis in 75%. One patient had polyarteritis nodosa-like vasculitis and four large-vessel vasculitis. Outcome was good except for one death. A highly sensitive next generation sequencing analysis on three Coxiella- and two Bartonella-related vasculitides biopsies did not find any bacterial DNA. Coxiella and Bartonella are both able to induce vasculitis but display distinct vasculitis features. Bartonella mimics PR3-ANCA-associated vasculitis in the setting of endocarditis, whereas Coxiella may induce vasculitis involving all vessel sizes.

Clinical and morphological characteristic of kidney damage in HIV/HCV co-infected patients who did not receive antiretroviral therapy

In the era of antiretroviral therapy (ART), the development of chronic kidney disease in HIV-infected patients is a significant complication not directly related to acquired immunodeficiency syndrome (AIDS), the risk of which is increased with co-infection with hepatitis C virus (HCV). The pathogenetic pathways of the development of kidney tissue damage and the formation of a morphological substrate for each of the viruses are different, but the immune-mediated mechanisms are a common link for the development of immune complex diseases. We studied renal necropsy samples in 20 patients with HIV/HCV co-infection who did not receive ART, and the dependence of the identified morphological substrate on the level of CD4+ in the blood, to assess and predict their morphogenesis. We observed predominantly segmental mesangial proliferation with an expansion of the mesangial matrix and glomerular involvement ≥50 % in 15 (75 %) cases and glomerular involvement &lt;50 % in 3 (15 %) cases. Endocapillary proliferation (E), infiltration of glomeruli with monocytes, neutrophil leukocytes, segmental macrophages were found in 2 (10 %) cases with the involvement of ≥ 50 % of glomeruli, which was regarded as an exudative component of the inflammatory response. In all cases, sclerosis of capillary loops was verified, which was mainly accompanied by their collapse, thickening of the capillary walls, namely the basement membranes of capillaries and segmental sclerosis of capillary loops of the glo­meruli of varying severity. Initial interstitial stromal fibrosis was found in 5 (25 %) cases, degenerative changes in the convoluted tubules — in 9 (45 %), mainly with the T0–T1 level. Positive expression of IgA, IgM, IgG, and C3 complement fractions in the form of linear and granular deposits along the capillary endothelium was detected with an intensity of “+” to “++”. We compared the verified morphological pattern and the level of CD4+ in the blood and found that patients with deeper immunosuppression show fewer changes, mainly characterized as sclerotic. Moreover, with an increase in the level of CD4+, the morphological substrate is enriched with a proliferative component. Expression of immunoglobulins and components of the complement system in immonohistochemical assay, in particular in areas of sclerotic changes, verifies the presence of prolonged immune complex associated lesions. To determine the detailed morphogenesis, it is advisable to perform a further correlation analysis of the data obtained with the control.

Possible role of higher serum level of myoglobin as predictor of worse prognosis in Sars Cov 2 hospitalized patients. A monocentric retrospective study

Background Limited data on myoglobin and infectious diseases are available. In this study we evaluate the potential role of myoglobin in predicting poor outcome in patients with Sars-Cov2 pneumonia. Method One hundred and twenty-one Sars-Cov 2 patients with average age of 69.9±13.2 years, and symptoms duration of 8.8±7.9 days were enrolled in the study. At the admission, the serum levels of myoglobin, erythrocyte sedimentation rate, C reactive protein (CRP), procalcitonin, ferritin, creatine phosphokinase, creatinine, fibrinogen, d-dimers, lactic dehydrogenase, troponin (Tn-I), creatine kinase myocardial band (CK-MB), complement fractions C3 and C4, immunoglobulins, interleukin 6 were evaluated. We also assessed the patients’ complete clinical history and performed a thorough physical examination including age, disease history and medications. Results Twenty-four (20%) patients died, and 18 (15%) patients required intensive care. The mean time between symptoms onset and death was 12.4 days ± 9.1. Univariate analysis of the patients’ data highlighted some independent risk factors for mortality in COVID-19, including higher neutrophils rate (HR: 1.171), lower lymphocytes rate (HR: 0.798), high CK-MB serum levels (HR: 1.6), high Tn-I serum levels (HR: 1.03), high myoglobin serum levels (HR: 1.014), Alzheimer (HR 5.8), and higher CRP values (HR: 1.011). Cox regression analysis model revealed that higher serum values of myoglobin (HR 1.003; 95%CI: 1.001-1.006; p=0.01), and CRP (HR 1.012; 95% CI: 1.001 – 1.023; p=0.035) could be predictors of mortality in COVID-19 patients. The value of myoglobin level for predicting 28 days-mortality using ROC curve was 121.8 ng/dL. Lower survival rate was observed in patients with serum levels of myoglobin>121.8 ng/dL (84% vs 20% respectively, p=0.0001). Conclusion Our results suggest that higher serum levels of myoglobin could be considerable an effective predictor of poor outcomes in COVID-19 patients; a careful follow-up in these patients is strongly suggested. The possibility of enhancing these findings in other cohorts of COVID-19 patients could validate the clinical value of myoglobin as a biomarker for worse prognosis in COVID-19.

Variations immunologiques après traitement d’un épisode maniaque

Bipolar disorder is a chronic and disabling mental illness affecting approximately 1–2% of the general population, characterized by the occurrence of manic episodes alone or alternating with depressive episodes. Bipolar disorder is associated with significant morbidity, mortality and personal suffering. The mechanisms underlying the onset and progression of bipolar disease are still poorly understood. Recently, immunological dysfunctions have been suggested in the pathogenesis of bipolar disorder, and many studies have focused on the interaction between bipolar disorder and immunity. Immunological changes have been widely studied during depressive episodes but less explored during manic episodes. The objective of our study was to explore changes in serum proteins and autoantibodies after treatment for a manic episode of bipolar I disorder. This study was carried out over a 30-month period from January 2017 to June 2019, in collaboration between the psychiatry department B of the Hédi Chaker CHU and the immunology department of the Habib Bourguiba CHU, in Sfax, Tunisia. It focused on a sample of 45 bipolar patients with manic relapse, naïve to psychotropic treatment, or discontinuing treatment for a period of at least three months and without a history of autoimmune disease. The study was conducted in two stages : on admission and after treatment. The mean plasma levels of IgG and complement C3 fraction were significantly higher in bipolar patients with relapsing mania. Studies of variation in immunoglobulins and complement fractions during relapses of bipolar disorder have all objected to variations in these serum proteins, but their results were inconsistent regarding the direction of variation and the fractions affected. After treatment, there was a statistically significant increase in the mean plasma levels of IgG and IgA and a decrease in the mean plasma level of the C4 fraction of complement. No significant variation in autoantibodies was noted after treatment. The mean plasma IgM level was significantly lower with sodium valproate. On atypical antipsychotic medication, the mean plasma level of fraction C3 was statistically lower, whereas on conventional antipsychotic medication it was statistically higher. This is in line with the data in the literature which support the immunomodulatory role of thymoregulators and antipsychotics. Serum proteins have been more sensitive than autoantibodies to the effect of psychotropic therapy during manic relapse.

OSTEOARTHRITIS AND IMMUNITY

Abstract&#x0D; Low-grade inflammation is part of the pathogenesis of osteoarthritis (OA) from its earliest stages and contributes to the acceleration of the degenerative process. Innate immunity has a leading role in it.&#x0D; Activation of the innate immune response is initiated by stimulation of the receptors on the cell membrane to recognize the secreted PAMPs (pathogen-associated molecular patterns). However, PAMPs can also be activated by endogenous damage-related molecular patterns (DAMPs). The group of DAMPs also includes toll-like receptors (TLRs).The disruption of matrix homeostasis in the course of OA is an example of activation of these receptors in chronic damage.&#x0D; The complement system is a key element of the innate immune system. It is one of the serum enzyme systems whose function is to opsonize antigens. The complement receptors on the surface of the cell membranes adhere to the targets for phagocytosis. The C3R fraction activates the complement cascade itself, as well as the oxygen metabolism of the cell, which is essential for the phagocytosis. The cartilage damage products released during joint damage are a separate class of potent complement modulators. Complement fractions bind to complement receptors on the surface of the chondrocyte and the synoviocyte cell membranes by TLR. The complement system is involved in many processes in the course of osteoarthritis: chondrocyte degeneration, ECM degradation, low-grade inflammation in the osteoarthritis, cell lysis, unbalanced bone remodeling, osteophyte formation, and neoangiogenesis. Whether drug control of complement activation may be a future therapeutic strategy in the treatment of OA and prevent its progression is a subject of future studies.

POS-157 ACUTE POST-INFECTIOUS GLOMERULONEPHRITIS IN CHILDREN: ABOUT A SERIES OF 83 CASES

Post-infectious acute glomerulonephritis (PI-AGN) is very common among Moroccan children. IT can be defined as an acute, non-suppurative, diffuse, generalized inflammation of the glomeruli of both kidneys. It occurs after an infection (of the skin or the upper respiratory tract). Group A beta-hemolytic (GABH) streptococcus is the most incriminated infectious agent. PI-AGN prognosis depends on the severity of renal involvement, with the possibility of chronic renal disease in the worst cases. The aim of our study is to determine the epidemiological, clinical, histological, and evolutive features of PI-AGN in children treated in our center. For that reason, we gathered retrospective data of 83 children. The study took place from January 2016 to June 2020. The median of age was 9 years. Distribution by sex was in favor of males with 65%. Most cases (91%) were seen in winter. The most involved infectious sites were the upper respiratory tract (74%), and the skin (24%). The infection was still active at diagnosis in 30% of cases, while the remaining cases had it at least one week before. Microscopic hematuria and proteinuria were always present. Gross hematuria, generalized edema, and hypertension were also very common (seen respectively in 77%, 82%, and 65% of the cases). Other symptoms reported at diagnosis of PI-AGN were abdominal pain and vomiting (71%), convulsions (17%), and oliguria (13.3%). Acute kidney failure was found at onset in 25 children, from whom two had dialysis. The C3 complement fraction was low in 68 patients, and the ASLO titers were high in 53% of cases. All patients were under water and salt restriction. Furosemide was the first-line treatment of hypertension and oliguria patients, and nicardipine was added when blood pressure targets were not achieved. Renal biopsy was performed on 14 children. The main indications were nephrotic syndrome, persistent proteinuria, rapidly progressive glomerulonephritis (respectively in 22, eight, four, and two patients). The renal biopsy findings were as follows: endocapillary GN with C3 deposits in 14 children, minimal change disease in four children, membranous GN in one patient, crescent GN in two children, and glomerulosclerosis with C3 deposits in one child. Oral steroids (nephrosis regiment) were prescribed in 40%. Meanwhile, intravenous methylprednisolone (1g/1.73m2 three days in a row) and cyclophosphamide (500 mg/m2/month for six months) was indicated in severe cases (respectively 23% and 9.6% of cases). All our 83 children had a good prognosis, and no cases of chronic kidney disease were noted at follow-up. PI-AGN is still very common in Morocco, mainly because GABH-streptococcus upper respiratory tract infections are still frequent in our children. However, the prognosis remains good if the appropriate management is started early.