Increased microchimerism in peripheral blood of women with systemic lupus erythematosus: relation with pregnancy.

OBJECTIVES: We aimed to determine the presence, amount and origin of microchimerism in peripheral blood of pregnant and non-pregnant parous women with systemic lupus erythematosus (SLE) as compared to control subjects. METHODS: We performed a comparative study in which peripheral blood was drawn from eleven female non-pregnant SLE-patients and 22 control subjects, and from six pregnant SLE-patients and eleven control subjects during gestation and up to six months postpartum. Quantitative PCR for insertion-deletion polymorphisms and null alleles was used to detect microchimerism in peripheral blood mononuclear cells and granulocytes. RESULTS: Microchimerism was detected more often in non-pregnant SLE-patients than control subjects (54.4% vs. 13.6%, respectively; p=0.03). When present, the median total number of foetal chimeric cells was 5 gEq/106 in patients and 2.5gEq/106 in control subjects (p=0.048). Microchimerism was mostly foetal in origin; maternal microchimerism was detected in one patient and one control subject. In control subjects, microchimerism was always derived from only one source whereas in 50% of patients it originated from multiple sources. The pregnant patients had a significantly higher median number of foetal chimeric cells in the granulocyte fraction just after delivery than control subjects (7.5 gEq/106 vs. 0 gEq/106, respectively; p=0.02). CONCLUSIONS: Just after delivery, SLE-patients had more microchimerism than control subjects. Three months post-partum, microchimerism was no longer detectable, only to reappear many years after the last pregnancy, more often and at higher levels in SLE-patients than in control subjects. This suggests that these chimeric cells may originate from non-circulating foetal chimeric stem cells.

Incidence of Malignancies in Patients With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Diagnosed Between 1991 and 2013.

OBJECTIVE: To investigate the incidence of malignancies during longitudinal followup of patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), and to examine the effect of immunosuppressive therapy on malignancy risk in these patients. METHODS: The study population consisted of patients with histopathologically confirmed AAV, diagnosed between 1991 and 2013 at a large university hospital. The mean duration of followup was 10 years. Malignancy incidence was assessed using the Dutch National Pathology Database. Incidence rates from the Netherlands Cancer Registry were used to compare malignancy incidence in the AAV cohort to that in the general Dutch population. RESULTS: Thirty-six of 138 patients with AAV developed a total of 85 malignancies during a mean followup of 9.7 years. The sex-, age-, and calendar year-adjusted malignancy risk was 2.21-fold higher (95% confidence interval [95% CI] 1.64-2.92) than that in the general population. Non-melanoma skin cancers occurred most frequently (standardized incidence ratio 4.23 [95% CI 2.76-6.19]). The incidence rates of other malignancies were not significantly increased. Malignancy risk was associated with the duration of cyclophosphamide (CYC) therapy and, interestingly, was not increased in patients who had received CYC for <1 year. CONCLUSION: Patients with AAV have a higher risk of malignancy than the general population, but this risk is accounted for solely by non-melanoma skin cancers. Over the years, the risk of other malignancies-specifically bladder and hematologic malignancies-has decreased in patients with AAV. This finding reflects ongoing efforts to reduce CYC exposure by developing new treatment regimens.