POS0822 HYPERTROPHIC PACHYMENINGITIS IN ANTINEUTROPHIL CYTOPLASMIC ANTIBODY-ASSOCIATED VASCULITIS: A MULTICENTER SURVEY IN JAPAN

Background

Hypertrophic pachymeningitis (HP), characterized by an inflammatory disorder indicating intracranial or spinal thickening of dura mater, is found to develop as a neurological involvement in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Meanwhile, the previous studies focusing on HP in AAV have been reported as a single-institution study, and the analyses were performed in a small number of patients because HP is a rare neurological disorder. Therefore, neither etiological nor clinical characteristics of HP in AAV have been adequately elucidated.

Objectives

This study clarified the characteristics of HP in AAV by analyzing the information of multicenter study in Japan (Japan collaborative registry of ANCA-associated vasculitis: J-CANVAS).

Methods

We analyzed the clinical information from 541 Asian patients with AAV enrolled in J-CANVAS. Of them, newly diagnosed and relapsed AAV were included in 448 and 93, respectively. The epidemiological and clinical findings were compared between patients with and without HP. Clinical manifestations related to AAV were evaluated based on the Birmingham Vasculitis Activity Score version 3. To elucidate independent factors in HP development, logistic regression analyses were additionally performed.

Results

Of the total 541 patients (mean age: 71±14 years, M:F = 1:1.2), HP was demonstrated in 28 (5.17%), including 17 (3.79%) in newly diagnosed AAV and 11 (11.8%) in relapsed AAV. The classification of granulomatosis with polyangiitis (GPA) was significantly higher in patients with HP than those without HP (50% vs. 21%, p = 0.0007). In newly diagnosed AAV, patients with HP significantly had higher GPA classification and higher positivity for PR3-ANCA than those without HP (53% vs. 17%, p = 0.001; 29% vs. 9%, p = 0.015, respectively). Conversely, positivity for MPO-ANCA was significantly higher in patients with HP than those without HP in relapsed AAV (91% vs. 55%, p = 0.025), despite not significantly different in the classification of AAV. Headache and cranial neuropathies were significant neurological symptoms in patients with HP compared to those without HP (82% vs. 6.6%, p < 0.0001; 32% vs. 2.9%, p < 0.0001, respectively). Besides, ear, nose and throat (ENT) and mucous membranes/eyes were significantly higher involvements in patients with HP than in those without HP (54% vs. 26%, p = 0.003; 29% vs. 9%, p = 0.003, respectively). Moreover, higher complications of “conjunctive hearing loss” and “sudden visual loss”, which are included in the categories of ENT and mucous membranes/eyes involvement, respectively, were significantly indicated in patients with HP than those without HP (39% vs. 7.2%, p < 0.0001; 21% vs. 1.2%, p < 0.0001, respectively). Multivariable logistic regression analysis identified that ENT (odds ratio [OR] 1.28, 95% confident interval [CI] 1.09 to 1.49, p = 0.002) and mucous membranes/eyes involvement (OR 1.37, CI 1.14 to 1.65, p = 0.0006), as well as conjunctive hearing loss (OR 4.52, CI 1.56 to 13.05, p = 0.005) and sudden visual loss (OR 1.84, CI 1.12 to 3.00, p = 0.015), were independent related factors in patients with HP.

Conclusion

GPA could be significantly classified in patients with HP. Notably, patients with HP significantly showed higher positivity for PR3-ANCA than those without HP in newly diagnosed AAV. Furthermore, sudden visual loss and conjunctive hearing loss might be implicated in HP development.

Disclosure of Interests

None declared

AB0625 Association between Cytomegalovirus Reactivation and Renal Prognosis during Remission Induction Therapy for ANCA-Associated Vasculitis

Background

Cytomegalovirus (CMV) has been associated with atherosclerosis in patients with chronic renal failure, and may cause secondary nephrotic syndrome. Therefore, we hypothesized that the reactivation of CMV by immunosuppressive therapy in patients with vasculitis may affect renal function.

Objectives

The purpose of this study was to investigate relationships between CMV infection and renal function during ANCA-associated vasculitis remission induction therapy.

Methods

This retrospective cohort study enrolled microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis patients at 25 sites in Japan who had a first or severe relapse between January 2017 and June 2020. Of these, patients with MPA or GPA who had a positive renal lesion score on BVAS (version 3) at baseline, or vasculitis findings on renal biopsy, CMV assayed by 48 weeks of treatment, were included. Patients were divided into two groups based on the presence or absence of a positive CMV antigen test during the remission induction phase (0–48 weeks of treatment). Outcomes were the rate of change in estimated glomerular filtration rate (eGFR) at 48 weeks after initiation of treatment in both groups, as determined by (eGFR at 48 weeks - eGFR at the initiation of treatment)/eGFR at the initiation of treatment; where lower values were associated with worse renal function. General linear models adjusted for age, gender, presence of diabetes or chronic kidney disease, and the use of rituximab or cyclophosphamide were generated.

Results

A total of 387 patients had CMV antigen measured during ANCA-associated vasculitis treatment, of which 164 had renal involvement and eGFR measured at 48 weeks. Seventy-seven (47.0%) were male and the median age was 75 years (range 69–80 years). CMV reactivation was observed in 44 patients (26.8%). The beta coefficient of multiple regression analysis with CMV positive as 1 and negative as 0 was 0.08 (95% confidence interval -0.13 to 0.29) (p = 0.47). The rate of change in eGFR was higher in the CMV positive group, but not statistically significantly.

Conclusion

Contrary to our hypothesis, renal prognoses tended to be better when CMV reactivation was observed. The patients in the CMV reactivation group may have been treated more aggressively, and some patients with a poor prognosis who were not followed up for 48 weeks dropped out. Further research investigating the adjustment of treatment methods is required.

Disclosure of Interests

None declared

POS0247 GLUCOCORTICOID TAPERING STRATEGY FOR ANCA-ASSOCIATED VASCULITIS: ADDRESSING THE GAP BETWEEN RECOMMENDATIONS AND REAL-WORLD PRACTICE

Background

Antineutrophil cytoplasmic antibody -associated vasculitis (AAV) is usually treated with combination of high-dose glucocorticoid (GC) and immunosuppressive agents, followed by tapering GC dose. Although the European League Against Rheumatism (EULAR) has specific recommendations for tapering the GC dose, clinicians often taper it slower than recommended due to concerns of potential disease relapse. However, such slower taper may prolong GC exposure for the patients, increasing the risk of adverse events, particularly infection.

Objectives

The aims of our study were (1) to clarify GC dose tapering in the treatment of AAV in a real-world setting, in contrast to the EULAR recommendation of 2015 and (2) to compare the incidence of AAV relapse and severe infection between patients underdoing EULAR-recommended tapering and those undergoing slower tapering than the recommendation.

Methods

In this multicenter (25 sites in Japan), observational, retrospective study of AAV, 541 patients who had initial or severe relapse were enrolled between January 2017 and June 2020. Of these, 349 patients with microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA) who entered in GC tapering phase after successful induction treatment were included. These patients were then grouped on the pace of GC tapering, defined as the GC dose at 12 weeks after treatment initiation: (1) EULAR group: 7.5-10 mg/day of GC, according to the EULAR recommendation of 2015, and (2) SLOWER group: >10 mg/day of GC. Their baseline characteristics and clinical outcomes were compared. Primary outcome was defined as relapse-free days from treatment initiation, whereas secondary outcome included the incidence of infectious events requiring hospitalization within 48 weeks from treatment initiation. Multivariable analysis was performed to assess the relationship between tapering pace and clinical outcomes.

Results

There were 44 patients (12.6%) in the EULAR group and 290 (83.2%) in the SLOWER group. Regarding baseline characteristics, compared with the EULAR group, the SLOWER group had significantly higher serum C-reactive protein level (EULAR, 5.89 ± 6.89 mg/dL vs SLOWER, 7.56 ± 6.01 mg/dL; p = 0.03), as well as a trend toward higher Birmingham Vasculitis Activity Score (version 3) (EULAR, 11.80 ± 7.01 SLOWER, 13.93 ± 7.06; p = 0.08) We did not observe any significant differences in the frequency of relapses between the two groups (EULAR, 8/44, 18.2% vs SLOWER, 55/290, 19.0%; p = 0.63). Multivariable Cox proportional hazard analysis revealed no relationship GC dose at 12 weeks from treatment initiation and incidence of relapse. However, upon logistic regression analysis, the SLOWER group was found to have significant higher risk of a severe infectious event within 48 weeks from treatment initiation (p = 0.046; hazard ratio, 1.27; 95% confidence interval, 1.004 – 1.601).

Conclusion

Our finding indicates that clinicians tended to taper GC slower for patients with higher disease activity. However, slower GC taper was not found to reduce the frequency of relapse. In addition, slower GC taper was found to increase the risk of a severe infection. Hence, clinicians should pay attention not only relapsing but also late GC taper resulting in the risk of serious infection, especially in patients with higher disease activity of AAV.

References

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Figure 1.

Acknowledgements

We would like to thank Editage (www.editage.com) for English language editing.

Disclosure of Interests

None declared

Response to Lefebvre et al

Congenital scoliosis (CS) is a common vertebral malformation with incidence of up to 1 of 1000 births worldwide. Recently, TBX6 has been reported as the first disease gene for CS: about 10% of CS patients are compound heterozygotes of rare null mutations and a common haplotype composed by 3 SNPs in TBX6. Lefebvre et al in this journal reported that 2 patients with spondylocostal dysostosis (SCD), a rare skeletal dysplasia affecting spine and ribs also have TBX6 mutations: 1 carried the microdeletion and a rare missense variant, and another 2 rare missense variants. We investigated the pathogenicity of the 3 missense variants in SCD by a luciferase assay. The results were negative for the proposal of Lefebvre et al. We consider these 2 SCD patients are more probably compound heterozygotes of null mutations and a common risk haplotype just as CS patients with TBX6 mutations.

Calmodulin binds to inv protein: implication for the regulation of inv function

Establishment of the left-right asymmetry of internal organs is essential for the normal development of vertebrates. The inv mutant in mice shows a constant reversal of left-right asymmetry and although the inv gene has been cloned, its biochemical and cell biological functions have not been defined. Here, we show that calmodulin binds to mouse inv protein at two sites (IQ1 and IQ2). The binding of calmodulin to the IQ2 site occurs in the absence of Ca(2+) and is not observed in the presence of Ca(2+). Injection of mouse inv mRNA into the right blastomere of Xenopus embryos at the two-cell stage randomized the left-right asymmetry of the embryo and altered the patterns of Xnr-1 and Pitx2 expression. Importantly, inv mRNA that lacked the region encoding the IQ2 site was unable to randomize left-right asymmetry in Xenopus embryos, implying that the IQ2 site is essential for inv to randomize left-right asymmetry in Xenopus. These results suggest that calmodulin binding may regulate inv function. Based on our findings, we propose a model for the regulation of inv function by calcium-calmodulin and discuss its implications.

FZD4S, a splicing variant of frizzled-4, encodes a soluble-type positive regulator of the WNT signaling pathway

Frizzled-1 (FZD1)-FZD10 are seven-transmembrane-type WNT receptors, and SFRP1-SFRP5 are soluble-type WNT antagonists. These molecules are encoded by mutually distinct genes. We have previously isolated and characterized the 7.7-kb FZD4 mRNA, encoding a seven-transmembrane receptor with the extracellular cysteine-rich domain (CRD). Here, we have cloned and characterized FZD4S, a splicing variant of the FZD4 gene. FZD4S, corresponding to the 10.0-kb FZD4 mRNA, consisted of exon 1, intron 1, and exon 2 of the FZD4 gene. FZD4S encoded a soluble-type polypeptide with the N-terminal part of CRD, and was expressed in human fetal kidney. Injection of synthetic FZD4S mRNA into the ventral marginal zone of Xenopus embryos at the 4-cell stage did not induce axis duplication by itself, but augmented the axis duplication potential of coinjected Xwnt-8 mRNA. These results indicate that the FZD4 gene gives rise to soluble-type FZD4S as well as seven-transmembrane-type FZD4 due to alternative splicing, and strongly suggest that FZD4S plays a role as a positive regulator of the WNT signaling pathway.

Isolation of Xenopus frizzled-10A and frizzled-10B genomic clones and their expression in adult tissues and embryos

Frizzled genes, encoding WNT receptors, play key roles in cell fate determination. Here, we isolated two Xenopus frizzled genes (Xfz10A and Xfz10B), probably reflecting pseudotetraploidy in Xenopus. Xfz10A (586 amino acids) and Xfz10B (580 amino acids) both encoded by a single exon, consisted of the N-terminal cysteine-rich domain, seven transmembrane domains, and the C-terminal Ser/Thr-X-Val motif. Xfz10A and Xfz10B were 97.0% identical at the amino acid level, and Xfz10B was 100% identical to previously reported Xfz9, yet Xfz10A was 85.3% and 62.4% identical to FZD10 and FZD9, respectively. Xfz10 mRNA appeared as 3.4 kb in adult tissues and embryos. RT-PCR analyses revealed the expression of more Xfz10A mRNA in stomach, kidney, eye, skeletal muscle, and skin, and more Xfz10B mRNA in heart and ovary, but in embryos, two mRNAs were equally expressed from the blastula stage with their peak expression at the late gastrula stage. The main site of Xfz10 mRNA expression was neural fold at the neurula stage and the dorsal region of midbrain, hindbrain, and spinal cord at the tadpole stage. These results suggest that Xfz10 has important roles in neural tissue formation.

Maternal program of apoptosis activated shortly after midblastula transition by overexpression of S-adenosylmethionine decarboxylase in Xenopus early embryos

When we studied polyamine metabolism in Xenopus embryos, we cloned the cDNA for Xenopus S-adenosylmethionine decarboxylase (SAMDC), which converts SAM (S-adenosylmethionine), the methyl donor, into decarboxylated SAM (dcSAM), the aminopropyl donor, and microinjected its in vitro transcribed mRNA into Xenopus fertilized eggs. We found here that the mRNA injection induces a SAM deficient state in early embryos due to over-function of the overexpressed SAMDC, which in turn induces inhibition of protein synthesis. Such embryos developed quite normally until blastula stage, but stopped development at the early gastrula stage, due to induction of massive cell dissociation and cell autolysis, irrespective of the dosage and stage of the mRNA injection. We found that the dissociated cells were TUNEL-positive, contained fragmented nuclei with ladder-forming DNA, and furthermore, rescued completely by coinjection of Bcl-2 mRNA. Thus, overexpression of SAMDC in Xenopus embryos appeared to switch on apoptotic program, probably via inhibition of protein synthesis. Here, we briefly review our results together with those reported from other laboratories. After discussing the general importance of this newly discovered apoptotic program, we propose that the maternal program of apoptosis serves as a surveillance mechanism to eliminate metabolically severely-damaged cells and functions as a 'fail-safe' mechanism for normal development in Xenopus embryos.

Overexpression of S-adenosylmethionine decarboxylase (SAMDC) in early Xenopus embryos induces cell dissociation and inhibits transition from the blastula to gastrula stage

Xenopus early embryos contain relatively low levels of S-adenosyl-methionine decarboxylase (SAMDC) and its mRNA. When SAMDC mRNA was injected into Xenopus embryos, it was preserved until the blastula stage and induced a large increase in SAMDC activity. The SAMDC-overexpressed embryos developed normally until the blastula stage but at the early gastrula stage cells which received the mRNA, dissociated autonomously and stopped synthesizing protein. In a hypotonic medium, the dissociated cells, and hence whole embryos, autolyzed. However, in isotonic media dissociated cells did not autolyze, although they did not divide and their DNA and RNA synthesis activity was greatly inhibited. The effects of SAMDC overexpression were abolished by coinjection of ethylglyoxal-bis(guanylhydrazone) (EGBG), a specific inhibitor of SAMDC. In SAMDC-overexpressed embryos the level of putrescine decreased and that of spermidine increased, though to limited extents, resulting in a considerable decrease in the putrescine/spermidine ratio. However, direct injection of spermidine did not mimic the effect of SAMDC overexpression, and putrescine coinjected with SAMDC mRNA to maintain the normal putrescine/spermidine ratio did not rescue the embryos. Conversely, the level of S-adenosylmethionine (SAM) greatly decreased and coinjection of SAM, which restored the level of SAM, rescued the embryos. We concluded that in SAMDC-overexpressed embryos a SAM-deficient state was induced and this caused cell dissociation and inhibition of transition from the blastula to gastrula stage. We suggest that the SAM-deficient embryos obtained in the present study provide a unique system for studying the cellular control mechanism underlying the blastula-gastrula transition.