SEASONAL VARIATIONS OF PRIMARY IMMUNE THROMBOCYTOPENIA INCIDENCE IN ADULTS
(Abstract release date: 05/19/16)
EHA Library. Moulis G. 06/09/16; 132964; E1415
Disclosure(s): None
Dr. Guillaume Moulis
Contributions
Contributions
Abstract
Abstract: E1415
Type: Eposter Presentation
Background
Seasonal variations of primary immune thrombocytopenia (ITP) incidence have been suggested in cohorts of childhood ITP. The existence of such variations is not well known in adult ITP.
Aims
The aims of this study were to assess the variations of primary ITP incidence in a clinical cohort of adult patients and to detect differences in seasonal patterns about the outcome of patients, differentiating ITPs lasting less than 3 months (defined by complete remission before 3 months: stable normal platelet count without any bleeding, without any exposure to treatment active on ITP) and ITPs lasting more than 3 months (i.e. persistent and chronic ITPs).
Methods
We conducted a retrospective study in the patient database of the French National Referral Center for Adult Autoimmune Cytopenias in Créteil, France. ITP was defined in accordance with international guidelines. We restricted the population to adult patients (aged ≥ 15 years) with primary ITP whose onset occurred between 1990 and 2014. ITP onset was defined by the date of first abnormal platelet count (<100 x 109/L) in patients with previous normal platelet count. Demographics data (age and gender), platelet count at ITP onset, bleeding score excluding the age at ITP onset, first line treatment and ITP activity at 3 months were also extracted from the database. We, then, calculated the proportion of patients with ITP symptoms onset by calendar month, with their 95% confidence intervals.
Results
Out of 663 primary ITP patients included in the study, 127 (19.1%) were excluded due to missing record of calendar month of first abnormal platelet count. Median age was 40.9 years (range: 15.0-94.2), and 358 (66.8%) were females. Median platelet count at ITP onset was 14.0x109/L and 131 (26.2%) patients had bleeding signs. Median Khellaf’s bleeding score excluding the age was 3 (range: 0-36). Out of these 536 patients, 321 (59.9%) became persistent or chronic (lasted more than 3 months) and 184 (34.3%) lasted less than 3 months (31 patients with missing value for this data). In regards to first-line treatment, 452 (84.3%) were treated by corticosteroids and 193 (36.0%) were exposed to with IVIg.Overall, there was a significantly higher proportion of patients with ITP onset in January/February than in August (nadir). Variations were marked in ITPs lasting less than 3 months. In this population, two smaller peaks of incidence were also observed: in June and in October. By contrast, there was no significant difference of ITP incidence by calendar month in ITPs that became persistent or chronic.
Conclusion
This study tends to confirm seasonal variations of ITP incidence with peak in winter and nadir in August in adults, as suggested by a previous population-based study in France. This pattern corresponds to influenza outbreak in France. The two smaller peaks (in June and in October) observed in ITP lasting less than 3 months are superimposable to enterovirus outbreaks in France. Both influenza and enterovirus have been associated with ITP occurrence in children. Moreover, vaccine against influenza tended to be protective against ITP onset in adults in a recent case-control study in France. In conclusion, this study suggests that ITP lasting less than 3 months in adults may be timely linked with major viral outbreaks in France, unlike persistent and chronic ITP. Further prospective epidemiological and microbiological studies are needed to confirm this observation.
Session topic: E-poster
Keyword(s): Epidemiology, Immune thrombocytopenia (ITP)
Type: Eposter Presentation
Background
Seasonal variations of primary immune thrombocytopenia (ITP) incidence have been suggested in cohorts of childhood ITP. The existence of such variations is not well known in adult ITP.
Aims
The aims of this study were to assess the variations of primary ITP incidence in a clinical cohort of adult patients and to detect differences in seasonal patterns about the outcome of patients, differentiating ITPs lasting less than 3 months (defined by complete remission before 3 months: stable normal platelet count without any bleeding, without any exposure to treatment active on ITP) and ITPs lasting more than 3 months (i.e. persistent and chronic ITPs).
Methods
We conducted a retrospective study in the patient database of the French National Referral Center for Adult Autoimmune Cytopenias in Créteil, France. ITP was defined in accordance with international guidelines. We restricted the population to adult patients (aged ≥ 15 years) with primary ITP whose onset occurred between 1990 and 2014. ITP onset was defined by the date of first abnormal platelet count (<100 x 109/L) in patients with previous normal platelet count. Demographics data (age and gender), platelet count at ITP onset, bleeding score excluding the age at ITP onset, first line treatment and ITP activity at 3 months were also extracted from the database. We, then, calculated the proportion of patients with ITP symptoms onset by calendar month, with their 95% confidence intervals.
Results
Out of 663 primary ITP patients included in the study, 127 (19.1%) were excluded due to missing record of calendar month of first abnormal platelet count. Median age was 40.9 years (range: 15.0-94.2), and 358 (66.8%) were females. Median platelet count at ITP onset was 14.0x109/L and 131 (26.2%) patients had bleeding signs. Median Khellaf’s bleeding score excluding the age was 3 (range: 0-36). Out of these 536 patients, 321 (59.9%) became persistent or chronic (lasted more than 3 months) and 184 (34.3%) lasted less than 3 months (31 patients with missing value for this data). In regards to first-line treatment, 452 (84.3%) were treated by corticosteroids and 193 (36.0%) were exposed to with IVIg.Overall, there was a significantly higher proportion of patients with ITP onset in January/February than in August (nadir). Variations were marked in ITPs lasting less than 3 months. In this population, two smaller peaks of incidence were also observed: in June and in October. By contrast, there was no significant difference of ITP incidence by calendar month in ITPs that became persistent or chronic.
Conclusion
This study tends to confirm seasonal variations of ITP incidence with peak in winter and nadir in August in adults, as suggested by a previous population-based study in France. This pattern corresponds to influenza outbreak in France. The two smaller peaks (in June and in October) observed in ITP lasting less than 3 months are superimposable to enterovirus outbreaks in France. Both influenza and enterovirus have been associated with ITP occurrence in children. Moreover, vaccine against influenza tended to be protective against ITP onset in adults in a recent case-control study in France. In conclusion, this study suggests that ITP lasting less than 3 months in adults may be timely linked with major viral outbreaks in France, unlike persistent and chronic ITP. Further prospective epidemiological and microbiological studies are needed to confirm this observation.
Session topic: E-poster
Keyword(s): Epidemiology, Immune thrombocytopenia (ITP)
Abstract: E1415
Type: Eposter Presentation
Background
Seasonal variations of primary immune thrombocytopenia (ITP) incidence have been suggested in cohorts of childhood ITP. The existence of such variations is not well known in adult ITP.
Aims
The aims of this study were to assess the variations of primary ITP incidence in a clinical cohort of adult patients and to detect differences in seasonal patterns about the outcome of patients, differentiating ITPs lasting less than 3 months (defined by complete remission before 3 months: stable normal platelet count without any bleeding, without any exposure to treatment active on ITP) and ITPs lasting more than 3 months (i.e. persistent and chronic ITPs).
Methods
We conducted a retrospective study in the patient database of the French National Referral Center for Adult Autoimmune Cytopenias in Créteil, France. ITP was defined in accordance with international guidelines. We restricted the population to adult patients (aged ≥ 15 years) with primary ITP whose onset occurred between 1990 and 2014. ITP onset was defined by the date of first abnormal platelet count (<100 x 109/L) in patients with previous normal platelet count. Demographics data (age and gender), platelet count at ITP onset, bleeding score excluding the age at ITP onset, first line treatment and ITP activity at 3 months were also extracted from the database. We, then, calculated the proportion of patients with ITP symptoms onset by calendar month, with their 95% confidence intervals.
Results
Out of 663 primary ITP patients included in the study, 127 (19.1%) were excluded due to missing record of calendar month of first abnormal platelet count. Median age was 40.9 years (range: 15.0-94.2), and 358 (66.8%) were females. Median platelet count at ITP onset was 14.0x109/L and 131 (26.2%) patients had bleeding signs. Median Khellaf’s bleeding score excluding the age was 3 (range: 0-36). Out of these 536 patients, 321 (59.9%) became persistent or chronic (lasted more than 3 months) and 184 (34.3%) lasted less than 3 months (31 patients with missing value for this data). In regards to first-line treatment, 452 (84.3%) were treated by corticosteroids and 193 (36.0%) were exposed to with IVIg.Overall, there was a significantly higher proportion of patients with ITP onset in January/February than in August (nadir). Variations were marked in ITPs lasting less than 3 months. In this population, two smaller peaks of incidence were also observed: in June and in October. By contrast, there was no significant difference of ITP incidence by calendar month in ITPs that became persistent or chronic.
Conclusion
This study tends to confirm seasonal variations of ITP incidence with peak in winter and nadir in August in adults, as suggested by a previous population-based study in France. This pattern corresponds to influenza outbreak in France. The two smaller peaks (in June and in October) observed in ITP lasting less than 3 months are superimposable to enterovirus outbreaks in France. Both influenza and enterovirus have been associated with ITP occurrence in children. Moreover, vaccine against influenza tended to be protective against ITP onset in adults in a recent case-control study in France. In conclusion, this study suggests that ITP lasting less than 3 months in adults may be timely linked with major viral outbreaks in France, unlike persistent and chronic ITP. Further prospective epidemiological and microbiological studies are needed to confirm this observation.
Session topic: E-poster
Keyword(s): Epidemiology, Immune thrombocytopenia (ITP)
Type: Eposter Presentation
Background
Seasonal variations of primary immune thrombocytopenia (ITP) incidence have been suggested in cohorts of childhood ITP. The existence of such variations is not well known in adult ITP.
Aims
The aims of this study were to assess the variations of primary ITP incidence in a clinical cohort of adult patients and to detect differences in seasonal patterns about the outcome of patients, differentiating ITPs lasting less than 3 months (defined by complete remission before 3 months: stable normal platelet count without any bleeding, without any exposure to treatment active on ITP) and ITPs lasting more than 3 months (i.e. persistent and chronic ITPs).
Methods
We conducted a retrospective study in the patient database of the French National Referral Center for Adult Autoimmune Cytopenias in Créteil, France. ITP was defined in accordance with international guidelines. We restricted the population to adult patients (aged ≥ 15 years) with primary ITP whose onset occurred between 1990 and 2014. ITP onset was defined by the date of first abnormal platelet count (<100 x 109/L) in patients with previous normal platelet count. Demographics data (age and gender), platelet count at ITP onset, bleeding score excluding the age at ITP onset, first line treatment and ITP activity at 3 months were also extracted from the database. We, then, calculated the proportion of patients with ITP symptoms onset by calendar month, with their 95% confidence intervals.
Results
Out of 663 primary ITP patients included in the study, 127 (19.1%) were excluded due to missing record of calendar month of first abnormal platelet count. Median age was 40.9 years (range: 15.0-94.2), and 358 (66.8%) were females. Median platelet count at ITP onset was 14.0x109/L and 131 (26.2%) patients had bleeding signs. Median Khellaf’s bleeding score excluding the age was 3 (range: 0-36). Out of these 536 patients, 321 (59.9%) became persistent or chronic (lasted more than 3 months) and 184 (34.3%) lasted less than 3 months (31 patients with missing value for this data). In regards to first-line treatment, 452 (84.3%) were treated by corticosteroids and 193 (36.0%) were exposed to with IVIg.Overall, there was a significantly higher proportion of patients with ITP onset in January/February than in August (nadir). Variations were marked in ITPs lasting less than 3 months. In this population, two smaller peaks of incidence were also observed: in June and in October. By contrast, there was no significant difference of ITP incidence by calendar month in ITPs that became persistent or chronic.
Conclusion
This study tends to confirm seasonal variations of ITP incidence with peak in winter and nadir in August in adults, as suggested by a previous population-based study in France. This pattern corresponds to influenza outbreak in France. The two smaller peaks (in June and in October) observed in ITP lasting less than 3 months are superimposable to enterovirus outbreaks in France. Both influenza and enterovirus have been associated with ITP occurrence in children. Moreover, vaccine against influenza tended to be protective against ITP onset in adults in a recent case-control study in France. In conclusion, this study suggests that ITP lasting less than 3 months in adults may be timely linked with major viral outbreaks in France, unlike persistent and chronic ITP. Further prospective epidemiological and microbiological studies are needed to confirm this observation.
Session topic: E-poster
Keyword(s): Epidemiology, Immune thrombocytopenia (ITP)
{{ help_message }}
{{filter}}