Blood cytopenias as manifestations of inherited metabolic diseases: a narrative review

Inherited Metabolic Diseases (IMD) encompass a diverse group of rare genetic conditions that, despite their individual rarity, collectively affect a substantial proportion, estimated at as much as 1 in 784 live births. Among their wide-ranging clinical manifestations, cytopenia stands out as a prominent feature. Consequently, IMD should be considered a potential diagnosis when evaluating patients presenting with cytopenia. However, it is essential to note that the existing scientific literature pertaining to the link between IMD and cytopenia is limited, primarily comprising case reports and case series. This paucity of data may contribute to the inadequate recognition of the association between IMD and cytopenia, potentially leading to underdiagnosis. In this review, we synthesize our findings from a literature analysis along with our clinical expertise to offer a comprehensive insight into the clinical presentation of IMD cases associated with cytopenia. Furthermore, we introduce a structured diagnostic approach underpinned by decision-making algorithms, with the aim of enhancing the early identification and management of IMD-related cytopenia.

Intravenous versus subcutaneous tocilizumab in Takayasu arteritis: multicentre retrospective study

OBJECTIVES

In this large multicentre study, we compared the effectiveness and safety of tocilizumab intravenous versus subcutaneous (SC) in 109 Takayasu arteritis (TAK) patients.

METHODS

We conducted a retrospective multicentre study in referral centres from France, Italy, Spain, Armenia, Israel, Japan, Tunisia and Russia regarding biological-targeted therapies in TAK, since January 2017 to September 2019.

RESULTS

A total of 109 TAK patients received at least 3 months tocilizumab therapy and were included in this study. Among them, 91 and 18 patients received intravenous and SC tocilizumab, respectively. A complete response (NIH <2 with less than 7.5 mg/day of prednisone) at 6 months was evidenced in 69% of TAK patients, of whom 57 (70%) and 11 (69%) patients were on intravenous and SC tocilizumab, respectively (p=0.95). The factors associated with complete response to tocilizumab at 6 months in multivariate analysis, only age <30 years (OR 2.85, 95% CI 1.14 to 7.12; p=0.027) and time between TAK diagnosis and tocilizumab initiation (OR 1.18, 95% CI 1.02 to 1.36; p=0.034). During the median follow-up of 30.1 months (0.4; 105.8) and 10.8 (0.1; 46.4) (p<0.0001) in patients who received tocilizumab in intravenous and SC forms, respectively, the risk of relapse was significantly higher in TAK patients on SC tocilizumab (HR=2.55, 95% CI 1.08 to 6.02; p=0.033). The overall cumulative incidence of relapse at 12 months in TAK patients was at 13.7% (95% CI 7.6% to 21.5%), with 10.3% (95% CI 4.8% to 18.4%) for those on intravenous tocilizumab vs 30.9% (95% CI 10.5% to 54.2%) for patients receiving SC tocilizumab. Adverse events occurred in 14 (15%) patients on intravenous route and in 2 (11%) on SC tocilizumab.

CONCLUSION

In this study, we confirm that tocilizumab is effective in TAK, with complete remission being achieving by 70% of disease-modifying antirheumatic drugs-refractory TAK patients at 6 months.

Partenariat patient : partage d’expérience dans le cas d’une crise vaso-occlusive drépanocytaire

The patient partnership is a new approach in which the patient, through his knowledge acquired from his experience with the disease, is a stakeholder in decisions about care, the organization of the health system and choices in terms of health policy. A team from the Blois hospital (41) was able to share the experience of a patient partnership during the analysis of a complex medical situation with a young man with sickle cell disease in a vaso-occlusive crisis. She reports here this new and enriching experience.

[Misdiagnosis of Gaucher disease in real life: Retrospective study of the French Gaucher's disease registry]

INTRODUCTION

Gaucher disease is an autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase which leads to an accumulation of glucosylceramide in the macrophages. Splenomegaly, hepatomegaly, cytopenias (anemia, thrombocytopenia) and bone disorders are the main symptoms. The diagnosis is often delayed, leading to unnecessary investigations and treatments, and delaying the specific treatment. The primary objective of our study was to establish, in patients who had a diagnostic delay of more than one year, the reported misdiagnoses before the final diagnosis. The secondary objectives were to investigate the risk factors associated with error and delayed diagnosis.

METHODS

Retrospective study including patients with Gaucher disease from the French Gaucher Disease Registry. Collection of data by a single investigator from a standardized form.

RESULTS

Among 83 patients with a known diagnostic delay, 13 patients (15 %) had one or two misdiagnoses. These included osteo-articular diagnoses (osteomyelitis, osteoarthritis, arthritis, osteochondritis, rheumatic fever, n=8), haematological diagnoses (gestational thrombocytopenia, immunological thrombocytopenia, n=4), infectious diagnoses (visceral leishmaniasis, mononucleosis, n=2) and hemochromatosis. The osteo-articular and infectious diagnoses concerned the child and the adolescent while the haematological diagnoses and the hemochromatosis concerned the adult. No factors were found associated with misdiagnoses. Patients with a diagnostic delay greater than one year were less likely to have hepatosplenomegaly as the first symptom.

CONCLUSION

There is a risk of diagnostic error related to phenotypic heterogeneity and lack of specificity of Gaucher disease symptoms. This study helps to better identify the misdiagnoses associated with Gaucher disease.

Immune thrombocytopenia and pregnancy: an exposed/nonexposed cohort study

The risk of immune thrombocytopenia (ITP) worsening during pregnancy and neonatal ITP (NITP) have never been prospectively studied. We included 180 pregnant and 168 nonpregnant women with ITP in a prospective, multicenter, observational cohort study. A total of 131 pregnant women with ITP were matched to 131 nonpregnant women with ITP by history of splenectomy, ITP status (no response, response, complete response), and duration. Groups were followed for 15 months. The primary outcome was the first occurrence of ITP worsening defined by a composite end point including bleeding events and/or severe thrombocytopenia (<30 × 109/L) and/or ITP treatment modification. We also studied the recurrence of ITP worsening and the incidence of NITP and risk factors. The first occurrence of ITP worsening did not differ between pregnant and nonpregnant women with ITP (53.4 per 100 person-years [95% confidence interval {CI}, 40.8-69.9] vs 37.1 [95% CI, 27.5-50.0]; hazard ratio {HR}, 1.35 [95% CI, 0.89-2.03], P = .16). Pregnant women with ITP were more likely to have recurrence of severe thrombocytopenia and treatment modification (HR, 2.71 [95% CI, 1.41-5.23], P = .003; HR, 2.01 [95% CI, 1.14-3.57], P = .017, respectively). However, recurrence of severe bleeding events was not different between groups (P = .4). Nineteen (14%) neonates showed NITP <50 × 109/L. By multivariable analysis, NITP was associated with a previous offspring with NITP and maternal platelet count <50 × 109/L within 3 months before delivery (adjusted odds ratio, 5.55 [95% CI, 1.72-17.89], P = .004 and 4.07 [95% CI, 1.41-11.73], P = .009). To conclude, women with ITP do not increase their risk of severe bleeding during pregnancy. NITP is associated with NITP history and the severity of maternal ITP during pregnancy. These results will be useful for counseling women with ITP.

Efficacy and safety of anakinra in adults presenting deteriorating respiratory symptoms from COVID-19: A randomized controlled trial

Objective

We aimed to investigate whether anakinra, an interleukin-1receptor inhibitor, could improve outcome in moderate COVID-19 patients.

Methods

In this controlled, open-label trial, we enrolled adults with COVID-19 requiring oxygen. We randomly assigned patients to receive intravenous anakinra plus optimized standard of care (oSOC) vs. oSOC alone. The primary outcome was treatment success at day 14 defined as patient alive and not requiring mechanical ventilation or extracorporeal membrane oxygenation.

Results

Between 27^th April and 6^th October 2020, we enrolled 71 patients (240 patients planned to been enrolled): 37 were assigned to the anakinra group and 34 to oSOC group. The study ended prematurely by recommendation of the data and safety monitoring board due to safety concerns. On day 14, the proportion of treatment success was significantly lower in the anakinra group 70% (n = 26) vs. 91% (n = 31) in the oSOC group: risk difference—21 percentage points (95% CI, -39 to -2), odds ratio 0.23 (95% CI, 0.06 to 0.91), p = 0.027. After a 28-day follow-up, 9 patients in the anakinra group and 3 in the oSOC group had died. Overall survival at day 28 was 75% (95% CI, 62% to 91%) in the anakinra group versus 91% (95% CI, 82% to 100%) (p = 0.06) in the oSOC group. Serious adverse events occurred in 19 (51%) patients in the anakinra group and 18 (53%) in the oSOC group (p = 0·89).

Conclusion

This trial did not show efficacy of anakinra in patients with COVID-19. Furthermore, contrary to our hypothesis, we found that anakinra was inferior to oSOC in patients with moderate COVID-19 pneumonia.

IgA vasculitis with underlying monoclonal IgA gammopathy: innovative therapeutic approach targeting plasma cells. A case series

OBJECTIVE

There is currently no evidence of the possible benefit of plasma cell-targeting therapies (PCTT) in immunoglobulin A (IgA) monoclonal gammopathy (MG) associated with IgA vasculitis (IgAV). We report the outcome of different PCTT regimens in a cohort of MG-IgAV.

METHODS

We used a French network to retrospectively describe the outcome of MG-IgAV patients treated with PCTT.

RESULTS

Five patients were included (mean age 65 years). All patients had severe baseline presentation including extensive necrotic purpura (n = 5), gastrointestinal involvement (n = 2), peripheral neuropathies (n = 2), and glomerulonephritis (n = 1). Two patients had IgA indolent multiple myeloma and three had IgA "MG of undetermined significance." Monotypic IgA deposition in the skin vessels wall was highlighted using an immunofluorescence assay. Cases of vasculitis in three patients (n = 3) were refractory to multiple line therapies, including cyclophosphamide (n = 3) or rituximab. Finally, PCTT including bortezomib plus cyclophosphamide and dexamethasone, bortezomib plus melphalan and prednisone, or bortezomib plus lenalidomide and dexamethasone were proposed, allowing complete remission in 4/5 patients without major adverse drug events.

CONCLUSION

This study suggests that the MG-IgAV phenotype might be distinctive of usual IgAV (severe and refractory to conventional immunosuppressive regimens) and supports the benefit of PCTT. This study sheds new light on the overall biology of IgAV, strengthening the pathogenic role of the monoclonal IgA component in IgAV.

Clinical phenotype and cytokine profile of adult IgA vasculitis with joint involvement

OBJECTIVE

Joint involvement can be observed during the course of adult IgA vasculitis (IgAV). However, clinical picture, prognosis, or pathophysiological data associated with this condition have been overlooked. We aimed to describe the clinical characteristics and outcome of IgAV patients with joint involvement and look to a specific cytokine profile.

METHODS

We analyzed clinical and biological data from a nationwide study that included adult IgAV patients. Presentation and outcomes of patients with or without joint involvement were compared at baseline and during follow-up. Plasma cytokine measurements of IgAV patients included in a prospective study were also analyzed using multiplex assays.

RESULTS

Among 260 patients, 62% had joint involvement. Among them, rheumatological manifestations included arthralgia (100%) or arthritis (16%), mostly involving the knees and ankles. In multivariate analysis, patients with joint involvement, compared to those without, were younger (p = 0.002; OR 0.87; 95% CI 0.80-0.95) and showed more frequent gastrointestinal tract involvement (p = 0.012; OR = 2.08; 95% CI 1.18-3.67). However, no difference in terms of clinical response, relapse, end-stage renal disease, or death was observed between groups. Among 13 cytokines measured, plasma interleukin (IL)-1β level was higher in patients with joint involvement compared to those without (mean ± SEM IL-1β, 3.5 ± 1.2 vs. 0.47 ± 0.1 pg/ml; p = 0.024) or healthy controls (vs. 1.2 ± 0.5 pg/ml; p = 0.076).

CONCLUSION

Joint involvement is frequent in adult IgAV and is associated with more frequent gastrointestinal involvement. Increased plasma IL-1β levels raise the question of targeting this cytokine in patients with chronic and/or refractory joint involvement. Key Points • Joint involvement in adult IgAV is a frequent manifestation. • Joint involvement is associated with more frequent gastrointestinal manifestations. • Interleukin-1β (IL-1β) might orchestrate joint inflammation in adult IgAV. • IL-1β might be a therapeutic target in patients with chronic and/or refractory joint involvement.

Efficacy and safety of TNF-α antagonists and tocilizumab in Takayasu arteritis: Multicenter retrospective study of 209 patients

OBJECTIVE

To assess safety and efficacy of TNF-α antagonists and tocilizumab in patients with Takayasu arteritis (TAK).

METHODS AND RESULTS

Two-hundred nine patients with TAK [median age of 29 years [7-62], and 186 (89%) females] were included. They received either TNF-α antagonists [n = 132 (63%) with 172 lines; infliximab (n = 109), adalimumab (n = 45), golimumab (n = 8), certolizumab (n = 6) and etanercept (n = 5)], or tocilizumab [n = 77 (37%) with 121 lines; intravenous and subcutaneous in 95 and 26 cases, respectively]. A complete response at 6 months was evidenced in 101/152 (66%) on TNF-α antagonists and 75/107 (70%) on tocilizumab, respectively. Age ≥ 30 years [OR = 2.09 [1.09; 3.99]] was associated with complete response, whereas vascular signs [0.26 [0.1; 0.65]], baseline prednisone ≥ 20 mg/day [0.51 [0.28; 0.93]] were negatively associated with the complete response to TNF-α antagonists or tocilizumab. During a median follow-up of 36 months, 103 relapses were noted. Supra-aortic branches and thoracic aorta involvements [HR 2.44 (1.06; 5.65) and 3.66 (1.18; 11.4), respectively], and systemic signs at baseline [HR 2.01 (1.30; 3.11)] were significantly associated with relapse. The cumulative incidence of treatment discontinuation and relapse were similar in TNFα antagonists and tocilizumab. Fifty-eight (20%) adverse effects occurred on biological-targeted therapies of whom 37 (21%) and 21 (17%), (p= 0.4) on TNF-α antagonists and tocilizumab, respectively.

CONCLUSION

This large multicentre study shows high efficacy of biological-targeted treatments in refractory TAK. Efficacy, relapse and drug retention rate were equivalent with TNF-α antagonists and tocilizumab.

White blood count, D-dimers, and ferritin levels as predictive factors of pulmonary embolism suspected upon admission in noncritically ill COVID-19 patients: The French multicenter CLOTVID retrospective study

Background

A high prevalence of pulmonary embolism (PE) has been described during COVID‐19. Our aim was to identify predictive factors of PE in non‐ICU hospitalized COVID‐19 patients.

Methods

Data and outcomes were collected upon admission during a French multicenter retrospective study, including patients hospitalized for COVID‐19, with a CT pulmonary angiography (CTPA) performed in the emergency department for suspected PE. Predictive factors significantly associated with PE were identified through a multivariate regression model.

Results

A total of 88 patients (median [IQR] age of 68 years [60‐78]) were analyzed. Based on CTPA, 47 (53.4%) patients were diagnosed with PE, and 41 were not. D‐dimer ≥3000 ng/mL (OR 8.2 [95% CI] 1.3‐74.2, sensitivity (Se) 0.84, specificity (Sp) 0.78, P = .03), white blood count (WBC) ≥12.0 G/L (29.5 [2.3‐1221.2], Se 0.47, Sp 0.92, P = .02), and ferritin ≥480 µg/L (17.0 [1.7‐553.3], Se 0.96, Sp 0.44, P = .03) were independently associated with the PE diagnosis. The presence of the double criterion D‐dimer ≥3000 ng/mL and WBC ≥12.0 G/L was greatly associated with PE (OR 21.4 [4.0‐397.9], P = .004).

Conclusion

The white blood count, the D‐dimer and ferritin levels could be used as an indication for CTPA to confirm PE on admission in non‐ICU COVID‐19 patients.

D-Dimer Level and Neutrophils Count as Predictive and Prognostic Factors of Pulmonary Embolism in Severe Non-ICU COVID-19 Patients

The incidence of pulmonary embolism (PE) is high during severe Coronavirus Disease 2019 (COVID-19). We aimed to identify predictive and prognostic factors of PE in non-ICU hospitalized COVID-19 patients. In the retrospective multicenter observational CLOTVID cohort, we enrolled patients with confirmed RT-PCR COVID-19 who were hospitalized in a medicine ward and also underwent a CT pulmonary angiography for a PE suspicion. Baseline data, laboratory biomarkers, treatments, and outcomes were collected. Predictive and prognostics factors of PE were identified by using logistic multivariate and by Cox regression models, respectively. A total of 174 patients were enrolled, among whom 86 (median [IQR] age of 66 years [55–77]) had post-admission PE suspicion, with 30/86 (34.9%) PE being confirmed. PE occurrence was independently associated with the lack of long-term anticoagulation or thromboprophylaxis (OR [95%CI], 72.3 [3.6–4384.8]) D-dimers ≥ 2000 ng/mL (26.3 [4.1–537.8]) and neutrophils ≥ 7.0 G/L (5.8 [1.4–29.5]). The presence of these two biomarkers was associated with a higher risk of PE (p = 0.0002) and death or ICU transfer (HR [95%CI], 12.9 [2.5–67.8], p < 0.01). In hospitalized non-ICU severe COVID-19 patients with clinical PE suspicion, the lack of anticoagulation, D-dimers ≥ 2000 ng/mL, neutrophils ≥ 7.0 G/L, and these two biomarkers combined might be useful predictive markers of PE and prognosis, respectively.

Gastrointestinal involvement in adult IgA vasculitis (Henoch-Schönlein purpura): updated picture from a French multicentre and retrospective series of 260 cases

OBJECTIVES

To describe the clinical presentation, treatments and prognosis of gastrointestinal (GI) involvement in adult IgA vasculitis (IgAV).

METHODS

Data from 260 adults with IgAV included in a French multicentre retrospective survey were analysed. Presentation and outcomes of patients with (GI+) and without (GI-) GI involvement were compared.

RESULTS

One hundred and thirty-seven (53%) patients had GI involvement. Initial manifestations were abdominal pain in 99%, intestinal bleeding in 31%, diarrhoea in 26% and acute surgical abdomen in only 4%. Abdominal imaging revealed thickening of intestinal wall in 61%, and endoscopies revealed abnormalities in 87%, mostly mucosal ulcerations. GI+ vs GI- patients were younger (46 ± 18 vs 54 ± 18 years; P = 0.0004), had more constitutional symptoms (43% vs 23%; P = 0.0005) and joint involvement (72 vs 50%; P = 0.0002), and higher CRP levels (3.7 vs 1.9 mg/dl; P = 0.001). Clinical response and relapse rates were comparable between groups, and all causes mortality (2 vs 4%) and IgAV-related mortality (1% vs 2%) as well. GI-related deaths were due to intestinal perforation and mesenteric ischaemia.

CONCLUSION

GI involvement is frequent in adult IgAV. GI involvement is frequent in adult IgAV. Mortality is not uncommon but does not seem to be specifically related to GI. Immunosuppressants should not be preferred as first-line therapy for GI+ patients but may be required in case of acute surgical abdomen.

Impact of aging on phenotype and prognosis in IgA vasculitis

OBJECTIVES

Immunoglobulin A vasculitis (IgAV) is a small-vessel vasculitis most frequently benign in children while the disease is more severe in adults. We aimed to study the impact of age on presentation and outcome of adult IgAV.

METHODS

We conducted a nationwide retrospective study including 260 IgAV patients. Patients were divided into four quartiles according to the age at IgAV diagnosis: <36; 36≤age < 52; 52≤age < 63 and ≥63 years. Comparison of presentation and outcome were performed according to age of disease onset.

RESULTS

Mean age at diagnosis was 50.1 ± 18 years and 63% were male. IgAV diagnosed in the lowest quartile of age was associated with more frequent joint (p< 0.0001) and gastrointestinal involvement (p= 0.001). In contrast, the oldest patients had more severe purpura with necrotic lesions (p= 0.001) and more frequent renal involvement (p< 0.0001), with more frequent hematuria, renal failure, higher urine protein excretion and more frequent tubulointerstitial lesions. Patients were treated similarly in all groups of age, and clinical response and relapse rates were similar between groups. In the 127 treated patients with follow-up data for >6 months, clinical response and relapse rates were similar between the four groups. Median follow-up was of 17.2 months (9.1-38.3 months). Renal failure at the end of follow-up was significantly more frequent in the highest quartile of age (p= 0.02), but the occurrence of end-stage renal disease was similar in all groups. Last, overall and IgAV-related deaths were associated with increase age.

CONCLUSION

Aging negatively impacts the severity and outcome of IgAV in adults. Younger patients have more frequent joint and gastrointestinal involvement, while old patients display more frequent severe purpura and glomerulonephritis.

Tocilizumab in treatment-naïve patients with Takayasu arteritis: TOCITAKA French prospective multicenter open-labeled trial

Objectives

To assess long-term efficacy of tocilizumab in treatment-naive patients with Takayasu arteritis (TAK).

Methods

Prospective open-labeled trial in naïve patients with TAK who received steroids at the dose of 0.7 mg/kg/day and 7 infusions of 8 mg/kg/month of tocilizumab. The primary endpoint was the number of patients who discontinued steroids after 7 infusions of tocilizumab. Secondary endpoints included disease activity and the number of relapses during 18-month follow-up.

Results

Thirteen patients with TAK were included, with a median age of 32 years [19–45] and 12 (92%) females. Six (54%) patients met the primary end-point. A significant decrease of disease activity was observed after 6 months of tocilizumab therapy: decrease of median NIH scale (3 [3, 4] at baseline, versus 1 [0–2] after 6 months; p < 0.001), ITAS-2010 score (5 [2–7] versus 3 [0–8]; p = 0.002), and ITAS-A score (7 [4–10] versus 4 [1–15]; p = 0.0001)]. During the 12-month follow-up after tocilizumab discontinuation, a relapse occurred among 5 patients (45%) out of 11 in which achieved remission after 6 months of tocilizumab.

Conclusion

Tocilizumab seems an effective steroid sparing therapy in TAK, but maintenance therapy is necessary.

Trial registration

ClinicalTrials.gov NCT02101333. Registered on 02 April 2014.

Rituximab-induced serum sickness is more frequent in autoimmune diseases as compared to hematological malignancies: A French nationwide study

INTRODUCTION

Rituximab induced serum sickness (RISS) is a rare delayed hypersensitivity reaction. The aim of this study was to describe the epidemiological and clinical characteristics of the RISS cases reported in France.

METHOD

Serum sickness cases involving rituximab were identified from the French PharmacoVigilance Database from 1998 to 2016.

RESULTS

We analyzed 37 cases of RISS. Rituximab was prescribed for an autoimmune disease in 78% of cases. Serum sickness occurred mainly after the first injection (54%) with a median time to onset of 12 days. The most frequent manifestations were rheumatologic symptoms (92%), fever (87%), and skin lesions (78%). The incidence was significantly higher when rituximab was used for autoimmune diseases than for a hematological malignancies. Taking into account the existence of a Systemic Lupus Erythematosus (SLE) as the indication of rituximab or as a comorbidity, the incidence of RISS in patients with SLE was even higher.

DISCUSSION

We report on the largest series of RISS studied to date and confirm that this reaction preferentially occurs in patients with autoimmune disease, especially SLE. This may be due to B-cell lysis, leading to the release of intracellular antigens into the serum and subsequent antigen-antibody complex formation, especially in patients with elevated autoantibody production. This could also explain why RISS often occurred after a single injection.

CONCLUSION

Patients generally recovered from RISS rapidly without obvious benefit from corticosteroid therapy. The risk of recurrence should prompt clinicians to question the use of rituximab after an episode of RISS.

Rituximab-associated Vasculitis Flare: Incidence, Predictors, and Outcome

OBJECTIVE

To report the incidence, predictors, and outcome of rituximab (RTX)-associated autoimmune disease flare.

METHODS

We conducted a retrospective study in a tertiary referral center from 2005 to 2015. Disease flare was defined as the onset of a new organ involvement or worsening of autoimmune disease within 4 weeks following RTX.

RESULTS

Among the 185 patients, we identified 7 disease flares (3.4%). All were due to type II mixed cryoglobulinemia vasculitis. Vasculitis flare occurred after a median time of 8 days (range 2-16) following RTX infusion and included acute kidney insufficiency (n = 7), purpura with cutaneous (n = 7), gastrointestinal (GI) tract involvement (n = 4), and myocarditis (n = 1). Patients with RTX-associated cryoglobulinemia vasculitis flare had these conditions more frequently: renal involvement (p = 0.0008), B cell lymphoproliferation (p = 0.015), higher level of cryoglobulin (2.1 vs 0.4 g/l, p = 0.0004), and lower level of C4 (0.02 vs 0.05, p = 0.023) compared to patients without flare after RTX (n = 43). Four patients (57%) died after a median time of 3.3 months. The 1-year survival rate was poorer in patients with vasculitis flare after RTX compared to their negative counterpart [43% (95% CI 18-100) vs 97% (95% CI 92-100), p < 0.001]. Immunofluorescence analysis of kidney biopsy in patients with worsening RTX-associated vasculitis highlighted the presence of RTX-, IgM-, and IgG1-positive staining of endomembranous deposits and thrombi within kidney lesions.

CONCLUSION

RTX-associated cryoglobulinemia vasculitis flare is associated with high mortality rate. We provided evidence that kidney lesions are due to immune complex deposition and to glomerular obstruction by cryoglobulinemia and RTX.

Efficacy and Safety of Anti-D Immunoglobulins versus Intravenous Immunoglobulins for Immune Thrombocytopenia in Children: Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVES

To compare the efficacy and safety of intravenous immunoglobulins (IVIG) and anti-D immunoglobulin (anti-D) in pediatric immune thrombocytopenia (ITP).

STUDY DESIGN

We conducted a systematic review and meta-analysis following PRISMA guidelines, including all randomized controlled trials that have assessed the efficacy and safety of anti-D and IVIG in children with ITP. We searched Medline, Embase, and Cochrane databases. Primary outcomes were the proportion of children achieving platelet count responses as defined in each study and bleeding response. Other safety outcomes included infusion reactions and hemolysis.

RESULTS

Eleven studies with 558 children were included. Anti-D was significantly inferior to IVIG at increasing platelet counts, both for thresholds of  >20 × 10⁹/L at 24-72 hours (response rate ratio for anti-D vs IVIG: 0.85, 95% CI 0.78-0.94) and  >50 × 10⁹/L at 24-72 hours (response rate ratio for anti-D vs IVIG: 0.75, 95% CI 0.61-0.92). Bleeding response was assessed in 4 studies, but some heterogeneity in reporting leads to unclear conclusion. General symptoms after anti-D infusion were less frequent than after IVIG (Peto OR 0.39, 95% CI 0.25-0.62). Hemolysis was more frequent after anti-D. The overall quality of the studies was low.

CONCLUSIONS

Compared with anti-D, IVIG led to a better response in terms of platelet count and may be preferred as a first-line treatment of ITP in children with acute hemorrhagic symptoms. However, the clinical significance of IVIG superiority on platelet count remains unclear.

Efficacy and safety of rituximab for systemic lupus erythematosus-associated immune cytopenias: A multicenter retrospective cohort study of 71 adults

The aim of the study was to assess the efficacy and safety of rituximab (RTX) for treating systemic lupus erythematosus (SLE)-associated immune cytopenias. This multicenter retrospective cohort study of adults from French referral centers and networks for adult immune cytopenias and SLE involved patients ≥18 years old with a definite diagnosis of SLE treated with RTX specifically for SLE-associated immune cytopenia from 2005 to 2015. Response assessment was based on standard definitions. In total, 71 patients, 61 women (85.9%), with median age 36 years [interquartile range 31-48], were included. The median duration of SLE at the time of the first RTX administration was 6.1 years [2.6-11.6] and the reason for using RTX was immune thrombocytopenia (ITP) for 44 patients (62.0%), autoimmune hemolytic anemia (AIHA) for 16 (22.5%), Evans syndrome for 10 (14.1%), and pure red cell aplasia for one patient. Before receiving RTX, patients had received a mean of 3.1 ± 1.3 treatments that included corticosteroids (100%), and hydroxychloroquine (88.5%). The overall initial response rate to RTX was 86% (91% with ITP, 87.5% with AIHA, and 60% with Evans syndrome), including 60.5% with complete response. Median follow-up after the first injection of RTX was 26.4 months [14.3-71.2]. Among 61 initial responders, relapse occurred in 24 (39.3%); for 18, RTX retreatment was successful in 16 (88.8%). Severe infections occurred after RTX in three patients, with no fatal outcome. No cases of RTX-induced neutropenia were observed. In conclusion, RTX seems effective and relatively safe for treating SLE-associated immune cytopenias.

Prevalence of immune-related systemic adverse events in patients treated with anti-Programmed cell Death 1/anti-Programmed cell Death-Ligand 1 agents: A single-centre pharmacovigilance database analysis

AIM

The growing use of immune checkpoint inhibitors (ICIs) is associated with the occurrence of immune-related adverse events (irAEs). Few data are published on systemic, immunohaematological and rheumatic irAEs. In a pharmacovigilance database analysis, we screened for these irAEs and calculated their prevalence.

PATIENTS AND METHODS

Participants were recruited via Registre des Effets Indésirables Sévères des Anticorps Monoclonaux Immunomodulateurs en Cancérologie (REISAMIC)¹ a French registry of grade ≥2 irAEs occurring in ICI-treated patients. The pathologies of interest were systemic autoimmune and inflammatory diseases, rheumatic diseases and immune cytopenia.

RESULTS

Out of 908 patients treated with anti-Programmed cell Death 1 (PD1)/anti-Programmed cell Death-Ligand 1 (PD-L1) agents (together with an anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) agent in 40 cases) between December 2012 and December 2016 at a single centre, 21 patients experienced systemic irAEs. The types and the prevalence of irAEs were as follows: immune thrombocytopenia (0.2%), Sjögren syndrome (0.3%), rheumatoid arthritis (0.2%), polymyalgia rheumatica (0.2%), psoriatic arthritis (0.2%), seronegative polyarthritis (0.7%) and sarcoidosis (0.2%). Patients with Sjögren syndrome or seronegative polyarthritis were more likely to have received combination therapy with ipilimumab (2.5% for both). We described these 21 cases, together with nine additional cases from five other centres. Most irAE were moderately severe (grade 2, 63%). The median time to onset was 57°days (interquartile range (IQR) 24-117). The ICI was withdrawn in 12 cases, 25 patients (83%) received corticosteroids, and five patients (17%) received immunosuppressant/immunomodulatory agents. The irAEs resolved fully or partially in 28 cases (93%).

CONCLUSION

Although systemic, immunohaematological and rheumatic diseases are rarely associated with ICI use, the prevalence is higher when two ICIs are combined. Corticosteroids are often effective and may enable the continued administration of ICIs. Studies designed to identify at-risk patients are warranted.

Antigenic burden and serum IgG concentrations influence rituximab pharmacokinetics in rheumatoid arthritis patients

AIMS

Rituximab is a monoclonal antibody directed against CD20, which is approved in rheumatoid arthritis (RA). This study aimed at assessing the influence of CD19+ cell counts as target-antigen amount, and of immunoglobulin G (IgG) serum concentrations on rituximab pharmacokinetics in RA patients.

METHODS

In a cohort of 64 RA patients who had received repetitive courses of rituximab, the influence of CD19+ cell count, IgG serum concentration, body surface area, sex and disease activity score in 28 joints on rituximab pharmacokinetic parameters was assessed using a population pharmacokinetic analysis.

RESULTS

A two-compartment model, with first-order distribution and elimination best described the data. The volume of distribution of central compartment and clearance of rituximab were estimated at 4.7 l and 0.56 l day^-1 , respectively. Distribution and elimination half-lives were 0.9 days and 17.3 days, respectively. As expected, the central volume of distribution increased with body surface area (P = 0.012) and was higher in male than in female (P = 0.004). We found that the elimination rate constant (k₁₀ ) increased with CD19+ count (P = 0.00022) and IgG concentration (P = 7.4 × 10^-8 ), and that k₁₀ decreased with time (P = 0.00015), partly explained by a change in target-antigen amount.

CONCLUSIONS

The association between CD19+ count and k₁₀ may be explained by target-mediated drug disposition, while the association between IgG serum concentration and k₁₀ may be explained by a saturation of the neonatal Fc receptor at high IgG concentrations, resulting in decreased recycling of rituximab.