Activated phosphoinositide 3-kinase δ syndrome: Update from the ESID Registry and comparison with other autoimmune-lymphoproliferative inborn errors of immunity

BACKGROUND

Activated phosphoinositide-3-kinase δ syndrome (APDS) is an inborn error of immunity (IEI) with infection susceptibility and immune dysregulation, clinically overlapping with other conditions. Management depends on disease evolution, but predictors of severe disease are lacking.

OBJECTIVES

This study sought to report the extended spectrum of disease manifestations in APDS1 versus APDS2; compare these to CTLA4 deficiency, NFKB1 deficiency, and STAT3 gain-of-function (GOF) disease; and identify predictors of severity in APDS.

METHODS

Data was collected from the ESID (European Society for Immunodeficiencies)-APDS registry and was compared with published cohorts of the other IEIs.

RESULTS

The analysis of 170 patients with APDS outlines high penetrance and early onset of APDS compared to the other IEIs. The large clinical heterogeneity even in individuals with the same PIK3CD variant E1021K illustrates how poorly the genotype predicts the disease phenotype and course. The high clinical overlap between APDS and the other investigated IEIs suggests relevant pathophysiological convergence of the affected pathways. Preferentially affected organ systems indicate specific pathophysiology: bronchiectasis is typical of APDS1; interstitial lung disease and enteropathy are more common in STAT3 GOF and CTLA4 deficiency. Endocrinopathies are most frequent in STAT3 GOF, but growth impairment is also common, particularly in APDS2. Early clinical presentation is a risk factor for severe disease in APDS.

CONCLUSIONS

APDS illustrates how a single genetic variant can result in a diverse autoimmune-lymphoproliferative phenotype. Overlap with other IEIs is substantial. Some specific features distinguish APDS1 from APDS2. Early onset is a risk factor for severe disease course calling for specific treatment studies in younger patients.

The histological diagnosis of dysplastic and neoplastic lesions in inflammatory bowel disease: a pathological perspective

Patients with inflammatory bowel disease (IBD), both ulcerative colitis (UC) and Crohn's disease (CD), are at an increased risk for developing colorectal carcinoma (CRC). The accurate diagnosis of dysplasia in biopsies taken during periodic surveillance of long-standing IBD patients is most important in prevention of UC and CD related cancer. Distinction of low from high grade IBD-related dysplasia and differential diagnosis between IBD-related dysplasia and dysplasia in sporadic adenoma as well as distinction from pseudodysplastic lesions in inflammatory pseudopolyps or reparative lesions is often very subtle and difficult and demands expertise of second experienced gastrointestinal pathologist. Although surveillance colonoscopy with multiple biopsies does not reduce the cancer mortality, it offers a reasonable chance of detecting precancer and performed prophylactic colectomy. Novel methods of detecting dysplasia are continuously being evaluated, including chromoscopy and molecular biology markers. In the future, one may expect, from these new markers to detect the dysplasia in IBD patients before development of histological evidence of neoplastic changes.