Incidence and prevalence of systemic sclerosis in Valcamonica, Italy, during an 18-year period

Objectives:

To investigate the epidemiology of systemic sclerosis in Valcamonica, an Italian Alpine valley, during an 18-year-long period.

Methods:

Patients with systemic sclerosis living in Valcamonica between 1999 and 2016 were identified by capture/recapture method using: (1) clinical databases of the only secondary Rheumatology Unit present in the valley and of the tertiary referral center for this area; (2) administrative data, extracting records with the International Classification of Diseases, 10th Revision, code for systemic sclerosis. Patients were included in the analysis when either the 1980 American Rheumatism Association classification criteria for systemic sclerosis or the 2013 American College of Rheumatology/European League Against Rheumatism criteria were satisfied. To study temporal changes, mean yearly incidence during three different 6-year interval was calculated. Prevalence rates were estimated at four different time points.

Results:

General population with age over 14 years living in Valcamonica varied during the evaluated period between 85,168 and 91,245 inhabitants. A total of 65 patients with systemic sclerosis were identified (female 84.6%, limited cutaneous systemic sclerosis: 84.6%; anticentromere: 64.6%). Systemic sclerosis incidence and prevalence increased during the study period (p = 0.029 and p < 0.0001, respectively). The increase of incidence was accounted for by cases satisfying only the 2013 criteria, with limited cutaneous systemic sclerosis, and with anticentromere, whereas the incidence of systemic sclerosis cases classified according to the 1980 criteria did not significantly increase. The prevalence at 31 December 2016 was 58.6 (95% confidence interval, 44.8–76.6) per 100,000 persons aged >14 years. Survival at 10 years after systemic sclerosis diagnosis was 83.0% (standard error, 5.6).

Conclusion:

Systemic sclerosis incidence and prevalence increased over time in this area, due to the increased recruitment of patients with milder forms of the disease.

Hypergammaglobulinemic purpura of Waldenström. (A report of serologic and immunogenetic studies and long-term follow-up in 18 patients)

Data from a study carried out on a group of 18 patients with hypergammaglobulinemic purpura of Waldenström (HPW) followed-up for 3-14 years are reported in this paper. In 11 patients the syndrome was considered to be idiopathic, while in the remaining 7 it was associated with Sjögren's syndrome (SS). A marked (17/1) female prevalence was observed. Purpura was the presenting clinical manifestation in 9 patients, but it occurred at different points during the course of the disease; Raynaud's phenomenon was present in one third of patients. Serum gammaglobulin levels were higher than 2.2 g/dl in all the cases and higher than 3 g/dl in 9 cases. Immune complexes were detected in all patients. A significant serologic finding in our case series was represented by the frequency of anti-Ro (16/16) and anti-La (14/15) antibodies, clearly higher than that reported in SS patients. HLA typing showed a marked increase of B8 and DR3 antigens as well as A1,B8,DR3 haplotype, never reported in other autoimmune diseases. On the basis of serologic and immunogenetic features, HPW seems a clearly distinguishable entity among autoimmune vasculitis.

Antibodies to cardiac Purkinje cells: further characterization in autoimmune diseases and atrioventricular heart block

We confirmed the occurrence of IgG antibodies reacting with ox cardiac conducting tissue in the serum of some human subjects. These antibodies failed to react with all ox cardiac conducting tissue cells; they reacted only with the cells defined as Purkinje cells. Having checked 352 sera, we found that the prevalence of antibodies to Purkinje cells was 11% in normal subjects (no correlation with sex and age), 14% in systemic lupus erythematosus, 21% in rheumatoid arthritis, 18% in progressive systemic sclerosis, and 23% in Sjögren syndrome. In 50 patients with permanent pacemakers for chronic non-postinfarction atrioventricular (AV) block the prevalence was 30% (P = 0.008). In a selected set of 29 patients with clinically idiopathic AV block located at or below the level of the His bundle the prevalence was 34.5% (P = 0.006). The possible role of anti-Purkinje cell antibodies in autoimmune damage of cardiac conduction tissue is discussed.

The cryoglobulinemic vasculitis

Thirty-eight patients with essential mixed cryoglobulinemia (EMC: 16 type II and 22 type III) were evaluated. Almost all patients had clinical manifestations which could be related to a cutaneous and/or visceral vasculitic process. No significant clinical or laboratory differences were found between type II and type III EMC patients. Kidney biopsy performed in 9 patients showed membranoproliferative glomerulonephritis in 6 cases, diffuse proliferative glomerulonephritis in 2 cases and mesangioproliferative glomerulonephritis in one case. Skin biopsy performed in 11 patients showed typical leukocytoclastic vasculitis as the most common finding. A picture consistent with overlapping vasculitis was found in 2 cases (one type II and one type III) and thrombus-like deposits were observed in 3 cases (2 type II and one type III). These thrombotic lesions, not associated with vessel wall necrosis and inflammatory infiltrate, were indistinguishable from those observed in one case of type I cryoglobulinemia. Our data emphasize the complexity of blood vessel involvement in cryoglobulinemia and point out the possible existence of multiple pathogenetic mechanisms.