Effectiveness of a multidisciplinary clinical pathway for women with systemic lupus erythematosus and/or antiphospholipid syndrome

OBJECTIVES

SLE and/or antiphospholipid syndrome (SLE/APS) are complex and rare systemic autoimmune diseases that predominantly affect women of childbearing age. Women with SLE/APS are at high risk of developing complications during pregnancy. Therefore, clinical practice guidelines recommend that patients with SLE/APS should receive multidisciplinary counselling before getting pregnant. We investigated the clinical effectiveness of implementing a multidisciplinary clinical pathway including prepregnancy counselling of patients with SLE/APS.

METHODS

A clinical pathway with specific evaluation and prepregnancy counselling for patients with SLE/APS was developed and implemented in a tertiary, academic hospital setting. Patients were prospectively managed within the clinical pathway from 2014 onwards and compared with a retrospective cohort of patients that was not managed in a clinical pathway. Primary outcome was a combined outcome of disease flares for SLE and thromboembolic events for APS. Secondary outcomes were maternal and fetal pregnancy complications.

RESULTS

Seventy-eight patients with 112 pregnancies were included in this study. The primary combined outcome was significantly lower in the pathway cohort (adjusted OR (aOR) 0.20 (95% CI 0.06 to 0.75)) which was predominantly determined by a fivefold risk reduction of SLE flares (aOR 0.22 (95% CI 0.04 to 1.09)). Maternal and fetal pregnancy complications were not different between the cohorts (respectively, aOR 0.91 (95% CI 0.38 to 2.17) and aOR 1.26 (95% CI 0.55 to 2.88)).

CONCLUSIONS

The outcomes of this study suggest that patients with SLE/APS with a pregnancy wish benefit from a multidisciplinary clinical pathway including prepregnancy counselling.

High prevalence of occult paragangliomas in asymptomatic carriers of SDHD and SDHB gene mutations

Hereditary paraganglioma is a benign tumor syndrome with an age-dependent penetrance. Carriers of germline mutations in the SDHB or SDHD genes may develop parasympathetic paragangliomas in the head and neck region or sympathetic catecholamine-secreting abdominal and thoracic paragangliomas (pheochromocytomas). In this study, we aimed to establish paraganglioma risk in 101 asymptomatic germline mutation carriers and evaluate the results of our surveillance regimen. Asymptomatic carriers of an SDHD or SDHB mutation were included once disease status was established by MRI diagnosis. Clinical surveillance revealed a head and neck paraganglioma in 28 of the 47 (59.6%) asymptomatic SDHD mutation carriers. Risk of tumor development was significantly lower in SDHB mutation carriers: 2/17 (11.8%, P=0.001). Sympathetic paragangliomas were encountered in two SDHD mutation carriers and in one SDHB mutation carrier. In conclusion, asymptomatic carriers of an SDHD mutation are at a high risk for occult parasympathetic paraganglioma. SDHB carrier risk is considerably lower, consistent with lower penetrance of SDHB mutations. For both syndromes, the risk of symptomless sympathetic paragangliomas is small.

Molecular characterization of novel germline deletions affecting SDHD and SDHC in pheochromocytoma and paraganglioma patients

A major cause of paraganglioma and pheochromocytoma is germline mutation of the tumor suppressor genes SDHB, SDHC, and SDHD, encoding subunits of succinate dehydrogenase (SDH). While many SDH missense/nonsense mutations have been identified, few large deletions have been described. We performed multiplex ligation-dependent probe amplification deletion analysis in 126 point mutation-negative patients, and here we describe four novel deletions of SDHD and SDHC. Long-range PCR was used for the fine mapping of deletions. One patient had a 10 kb AluSg-AluSx-mediated deletion including SDHD exons 1 and 2, the entire TIMM8B gene, and deletion of exons of C11orf57. A second patient had a deletion of SDHD exons 1 and 2 and exon 1 of the TIMM8B gene. A third patient showed a deletion of exon 2 of SDHD, together with a 235 bp MIRb-Tensin gene insertion. In a fourth patient, a deletion of exons 5 and 6 of the SDHC gene was found, only the second SDHC deletion currently known. The deletions of the TIMM8B and C11orf57 genes are the first to be described, but do not appear to result in an additional phenotype in these patients. Four of the eight breakpoints occurred in Alu sequences and all three SDHD deletions showed an intron 2 breakpoint. This study underlines the fact that clinically relevant deletions may encompass neighboring genes, with the potential to modify phenotype. Gene deletions of SDHD and SDHC represent a substantial proportion of all mutations, and must be considered in paraganglioma patients shown to be negative for mutations by sequencing.