Incidence Of Idiopathic Thrombocytopenic Purpura Research Articles

Role and Significance of T Help Cells 17 in Pathogenesis of Idiopathic Thrombocytopenic Purpura

To investigate the role and significance of T help cells 17(Th17) in pathogenesis of idiopathic thrombocytopenic purpura (ITP). Peripheral blood samples from ITP patients and normal controls were examined for Th17 cell proportion by flow cytometry (FCM). Expression of IL-17, IL-23, IL-6 and TGF-β1 in hematoplasma was detected by ELISA. The mRNA expression level of IL-17 and RORγt in peripheral blood mononuclear cells (PBMNC) from patients with ITP and normal controls were measured by RT-PCR technique, and expression levels of pSTAT3 and RORγt proteins were analyzed by Western-blot. Th17 cells in peripheral blood from patients with ITP was greatly increased when compared with normal control group (P<0.05). Expressions of IL-17, IL-23, IL-6 and TGF-β1 in hematoplasma of ITP patients were all significantly higher than those in normal control group (all P<0.01). mRNA expression levels of IL-17 and RORγt in PBMNC from patients with ITP were much higher than those in normal controls (P<0.05). Protein expressions of pSTAT3 and RORγt in PBMNC of ITP patients were greatly increased as compared with those in control (P<0.05). Th17 cell subgroup may play a role in incidence and development of ITP, which may participate in the pathogenesis of ITP by increasing Th17 cell proportion and altering the expression level of Th17-related cytokines as well as regulatory and transcriptional factors.

The Incidence and Characterization of ITP in Prostate Cancer

INTRODUCTION:Idiopathic thrombocytopenic purpura (ITP) is a common autoimmune disorder. The association between ITP and lymphoid neoplasms is well known, but the association of ITP with solid tumors is poorly documented. To date only one case of prostate cancer associated with ITP has been reported in the literature and the association was unclear. The purpose of this study is to estimate the incidence of ITP in men with prostate cancer and to characterize its clinical course.METHODS:We performed a retrospective cohort study using a large multi-institutional database of 3,258,677 US veterans to identify those with and without prostate cancer (ICD-9 code 185). We evaluated them during the years 2006-2011 for the development of ITP using ICD-9 code 287.31. We examined the association of the presence of prostate cancer with incident ITP using Cox proportional hazard analyses, with adjustments for age, race, and presence of systemic lupus erythematosus, lymphomas and rheumatoid arthritis.In order to increase the specificity and sensitivity of our evaluation and to analyze the characteristics associated with ITP in prostate cancer, we then evaluated patients visiting the Memphis Veterans Administration Medical Center (VAMC) between January 2006 and December 2011. We identified 3973 patients with prostate cancer and randomly selected 4801 patients without prostate cancer during the same time period. In both of these cohorts, we performed an in depth chart review of all the patients with thrombocytopenic disorders, expanding the ICD.9 codes to 287.31 (ITP) and 287.5 (Thrombocytopenia NOS). We identified patients with ITP based on the American Society of Hematology criteria for the diagnosis. We then reviewed the ITP identified charts for characteristics of disease.RESULTS:Among 3,258,677 US veterans without a baseline diagnosis of thrombocytopenia, we identified 265,446 patients with prostate cancer and 2,993,231 patients without prostate cancer. In both these cohorts 1,847 patients developed ITP according to ICD.9 code 287.31. The incidence of ITP in patients with prostate cancer was 12.3/100,000 patient years (95%CI: 10.7-14.2) and in patients without prostate cancer was 9.5/100,000 patient years (95% CL: 9.0-10.0). Prostate cancer was associated with a 30% higher risk of incident ITP in unadjusted analyses (hazard ratio, 95%CI: 1.30, 1.12-1.51, p=0.001), but the difference was non-significant after multivariable adjustments (adjusted HR, 95%CI: 1.11, 0.95-1.30, p=0.18). Men with prostate cancer were older than controls (mean age 69 vs 59). Patients with ITP were more likely to have lupus (2.0% vs. 0.2%), lymphomas (7.3% vs. 0.8%) and rheumatoid arthritis (3.6% vs. 1.8%).This analysis provided a broad correlation between ITP and prostate cancer but lacked sensitivity due to the specificity of the single ICD-9 code. In our chart review of 3973 veterans with prostate cancer, we identified six cases of ITP (30/100,000 patient years). Among 4801 veterans without prostate cancer, none developed ITP. These numbers were too small to demonstrate clinical significance. The prostate cancer patients in our local institution were older than the controls (67.6 vs 57.7), similar to the age discrepancy in the large VA database. In none of the patients with ITP, thrombocytopenia was attributable to prior irradiation or chemotherapy. Two patients had severe ITP episodes preceding prostate cancer progression. Four patients had ITP worsening with stable prostate cancer and one patient had stable ITP with prostate cancer progression. Two of the ITP patients never required treatment, three required and responded to steroids and immunosuppressive drugs, and of these one required splenectomy.CONCLUSION:ITP, identified by the ICD-9 code 287.31 in a large multi-institutional survey, occurs more often in patients with prostate cancer, but this association may be due to confounding variables such as age. The true incidence is likely higher than this. At the Memphis VAMC, utilizing broader ICD.9 codes, including both ITP and Thrombocytopenia NOS, followed by an in-depth chart review, there is a strong suggestion of an increased incidence of ITP among prostate cancer patients, but the numbers are too small to be clinically significant. The clinical course of ITP in prostate cancer patients is similar to that seen with other disorders and does not clearly parallel the course of the prostate cancer. DisclosuresNo relevant conflicts of interest to declare.

Post‐varicella thrombocytopenic purpura

The aim of the study was to characterize the clinical course of post-varicella idiopathic thrombocytopenic purpura (ITP) and to asses the risk of acquiring ITP after varicella infection. A retrospective study of all children diagnosed with ITP in a tertiary medical centre during 1998-2008. Findings were compared with the Intercontinental Childhood ITP Study Group database. The risk of acquiring ITP after a varicella infection was assessed. Ten children were diagnosed with post-varicella ITP. The incidence of post-varicella ITP was 1.9% amongst children diagnosed with ITP and 1.1% amongst children hospitalized for varicella. ITP was diagnosed, on average, 8.5 days after the onset of the varicella rash. The female-to-male ratio was 1:1.5. The average minimal platelet count was 9.5 × 10⁹ platelets/L. Post-varicella ITP had an acute course in 80% of cases and a chronic course in the remaining 20%. Bleeding episodes occurred in three patients. During the follow-up period, 11 patients with previously diagnosed ITP developed varicella. The infection had no apparent affect on the platelet count of the children with acute ITP, but caused a relapse in 71% of the patients with chronic ITP. Post-varicella ITP has similar clinical features and course to non-varicella associated ITP. The calculated risk of ITP as a complication of varicella infections is approximately 1:25,000.

The incidence of idiopathic thrombocytopenic purpura among adults: a population‐based study and literature review

Published data on the epidemiology of idiopathic thrombocytopenic purpura (ITP) among adults are very limited. We conducted a study of ITP incidence using the General Practice Research Database in the United Kingdom. From 1992 to 2005, there were 840 cases of ITP among adults considering 21 749 623 person-years (PYs) of follow-up, for a crude incidence of 3.9 per 100 000 PYs [95% confidence interval (CI): 3.6, 4.1]. The incidence was higher among women [4.5 per 100 000 PYs (95% CI: 4.2, 4.9)] than men [3.2 per 100 000 PYs (95% CI: 2.8, 3.5)]. Among both women and men, incidence was higher at older ages and in later study years. In a systematic review of previously published literature, incidence of ITP among adults ranged from 1.6 to 2.68 per 100 000 persons per year; prevalence ranged from 9.5 to 23.6 per 100 000 persons. In order to improve the understanding of the disease burden of ITP, future studies should include a clearly defined definition of ITP and focus on well-described source populations that are geographically and ethnically diverse.

Idiopathic thrombocytopenic purpura in childhood: a population-based study in Qatar

To find the pattern of idiopathic thrombocytopenic purpura (ITP) (acute/chronic) and to describe presenting features and clinical characteristics of the disease in children below 14 years of age in a newly developed Arabian society. This retrospective, descriptive study was carried out at the Pediatric Department of the Hamad General Hospital, Hamad Medical Corporation, Qatar. A total of 50 children below 14 years of age who were diagnosed with ITP during the period 2000-2005 were included. Among the studied children (50), 62% were diagnosed with acute ITP and 38% with chronic ITP. Acute ITP was more prevalent in boys (64.5%) when compared with girls (35.5%), whereas for chronic ITP, nearly an equal distribution was found in boys (57.9%) and girls (42.1%). Preceding viral infection was common in both acute (71%) and chronic (63.2%) ITP cases; 68% of the children with ITP showed a platelet count below 20x10(9)/L at the time of presentation. Most of the studied children were treated with intravenous immunoglobulin (74%). The study revealed a high incidence of ITP among children in Qatar. The study findings are in line with other international reports.

Prevalence Estimates of Adult Chronic Idiopathic Thrombocytopenic Purpura (ITP) in the United States.

ITP is a disease caused by inadequate platelet production as well as increased platelet destruction. Literature on the epidemiology of ITP is currently sparse and the disease remains poorly described. Based on previous reviews, the overall incidence of ITP among adults ranges from 1.6 to 3.0 per 100,000 person years of observation (PYO); prevalence estimates range from 2.1 to approximately 36.4 per 100,000 persons (Neylon AJ et al., Br J Haematol. 2003; Satia J et al., Eur Hematol Assoc. [poster presentation] 2006; Deitz AC et al., Blood. 2006). In this study, the objective was to estimate the prevalence of adult chronic ITP (in 2005) stratified by age and gender using a large US claims database (Integrated Healthcare Information Services, IHCIS). IHCIS comprises over 70 million patients from 45 health plans. Adult chronic ITP cases were defined as patients with at least two diagnoses (ICD-9 code 287.3) for primary thrombocytopenia separated by at least 6 months between 2002 and 2006, and age 18 or older in 2004. Although ICD-9 code 287.3 is not exclusive to ITP, its sensitivity and specificity are likely to be high (Segal et al., Am J Hem. 2004). A patient's first identified 287.3 ICD-9 code over the period 2002–2006 had to be in 2004 or earlier and the last one in 2004 or later. Patients had to have continuous enrollment throughout the year 2004. We estimated the 2004 prevalence as the total number of identified chronic ITP cases divided by the total population in the database in 2004 stratified by age group and gender. Estimates of adult cases for the US population were obtained by multiplying the 2004 prevalence estimates by the 2005 adult US census population estimates. The estimated adult prevalence was 23.6 [95% CI 23.4 – 23.8] per 100,000 persons, translating to approximately 52,700 (95% CI 52,200 – 53,100) adult chronic ITP cases in the US. Females had higher prevalence than males (28.1 vs 18.8 per 100,000). In addition, prevalence increased with age (from 17.0 in the age group 18–49 to 36.2 in the age group 65 and older). These results are broadly similar to previously published data and help to better understand the epidemiology of chronic ITP. While the tight CIs predominantly reflect the large data set rather than the precision of the estimates, we believe these data are among the most robust estimates of ITP prevalence and are the first to specifically estimate adult chronic ITP prevalence by age and gender in the US.

The Incidence of Idiopathic Thrombocytopenic Purpura (ITP) among Adults in the United Kingdom's General Practice Research Database (GPRD), 1992–2005.

ITP is a disease caused by inadequate platelet production as well as increased platelet destruction. Population-based literature on the epidemiology of ITP is currently sparse, but incidence has been estimated to be between 1.6 and 3.0 per 100,000 person years of observation (PYO) (Neylon AJ et al., Br J Haematol. 2003; Satia J et al., Eur Hematol Assoc [poster presentation] 2006). The objective of this study was to estimate the incidence rate of ITP in adults in the United Kingdom using the GPRD, which contains patient data from over 370 representative medical practices. Using diagnostic codes for ITP (D313000, D313012, 42P2.11, or D313.12 or the Oxford Medical Information System code 2871C) to define cases, incidence rates per 100,000 PYO with 95% confidence intervals (CI) were estimated. Incidence by age, gender, and time period (1992–1998, 1999–2005) was evaluated. Eight hundred forty adult cases of ITP (aged 18 years or more) during 21.7 million PYO from 1992 to 2005 were identified. The overall incidence rate (per 100,000 PYO) during this time was 3.9 (95% CI: 3.6, 4.1) with higher rates among women (4.6 [95% CI: 4.2, 4.9]) compared with men (3.2 [95% CI: 2.8, 3.5]). Incidence rates (per 100,000 PYO) increased with age (from 2.5 [95% CI: 2.2, 2.7] to 4.1 [95% CI: 3.6, 4.6] to 8.2 [95% CI: 7.3, 9.2] in the age groups 18–49, 50–69 and 70+ respectively), and in later study years (from 2.9 [95% CI: 2.5, 3.2] in the period 1992–1998 to 4.5 [95% CI: 4.1, 4.8] in the period 1999–2005). In summary, ITP was diagnosed in approximately 4 adults per 100,000 PYO in the General Practice Research Database. Incidence rates of ITP in this study are slightly higher than in previous estimates, possibly due to a code-based disease definition without validation by clinical and lab data. More population-based studies of the natural history of adult ITP are needed to better elucidate the burden of this disease.

2006 Prevalence Estimate of Idiopathic Thrombocytopenic Purpura (ITP) in the United States.

ITP is a rare but serious platelet disorder. It has been associated with fatal hemorrhage and reduced life expectancy (Cohen et al., Arch Intern Med, 2000). The incidence of ITP has been reported in two population-based studies in Europe (Neylon et al., Br J Haem, 2003; Frederiksen and Schmidt, Blood, 1999). However, there are no recent high quality studies that we are aware of regarding the burden of this disease (i.e., prevalence) in the US by gender and age group, and so we undertook this study in IHCIS (Integrated Healthcare Information Services), a US managed care database comprised of over 38 million patients from 30 health plans. ICD-9 code 287.3 (primary thrombocytopenia) was used as a proxy for an ITP diagnosis. Patients were required to have at least one diagnosis code in 2004 and a second diagnosis code in 2003, 2004 or 2005 to help minimize rule-out diagnoses. Continuous enrolment for a defined period of time also was required. Projected 2006 cases were obtained by multiplying the 2004 prevalence proportions by July 1, 2006 US population estimates (http://www.census.gov/ipc/www/usinterimproj). The projected number of patients with ITP in the US in 2006 was estimated to be 85,000 to 108,000, depending on the stringency of the inclusion criteria (i.e., whether the second occurrence of 287.3 in a patient record had to be within six months of the first). Slightly more of these cases were among women (56%) compared to men, and adults were diagnosed more frequently than those aged 0–15. This is the first study to estimate US prevalence counts using a managed care population, which includes both inpatients and outpatients. However, there are several limitations: ICD-9 code 287.3 is not exclusive to ITP. Segal et al. (Am J Hem, 2004) reported that sensitivity and specificity based on a single occurrence of this code was 100% and 89%, respectively, among inpatients, and 84% and 66%, respectively, among outpatients; our study required two code occurrences. Our estimate also assumes that the prevalence rate has remained constant from 2004 to present. Lastly, Frederiksen and Schmidt reported that the incidence of ITP was higher among older individuals. Therefore, we may be under-estimating the true prevalence of this disease in the general population because the elderly are somewhat under-represented in the IHCIS database.

Spontaneous Resolution of ITP in Two Elderly Patients.

Because adult idiopathic thrombocytopenic purpura (ITP) is often a prolonged illness with a high risk of major bleeding, guidelines have advocated immediate treatment of low platelet counts in such adults. We describe two elderly ITP patients with minor bleeding whose platelet counts normalized spontaneously within three months, raising the possibility that select adult ITP may not require treatment. The first patient is an 83 year old female who experienced spontaneous bruising with a platelet count of 5000/mm3. She had no significant medical history, did not drink alcohol or take medications known to cause thrombocytopenia, but did have a recent viral illness. Her peripheral blood smear showed scant platelets without clumping, microcytic but not hypochromic red cells, and no helmet cells or schistocytes. A bone marrow aspirate and biopsy revealed moderately increased megakaryocytes, mild dysplasia and reduced but present bone marrow iron stores. Without a change in medications or therapy for ITP, the platelet count rose to 20,000 overnight. The platelets were 46,000 at one week, normalized in three months, and remain stable at 226,000 three years later. The course was similar for a second patient, a 72 year old female who presented with painless hematuria, purpura and petechiae due to a platelet count of 9000/mm3. She had no medical history or antecedent viral illness, did not drink alcohol, and did not take thrombocytopenia-causing medications. The other cell lines and a peripheral blood smear were normal. Bone marrow examination revealed a hypocellular (20%) marrow with mild dysplasia and increased megakaryocytes. Without treatment, the platelets rose to 28,000 overnight and to 42,000 within 48 hours. The platelet count was 176,000 on day 5, 202,000 by day 82 and 202,000 at 21 months. Continuous improvement in the platelet level, measured initially every 8 to 12 hours, was characteristic of these two patients who received no therapy. In light of the hemorrhagic risks of ITP, the American Society of Hematology recommends urgent treatment of adults with platelet counts lower than 20,000, or less than 50,000 with significant mucus membrane bleeding. A consequence of these recommendations is that the outcome of untreated disease is unknown (George et al, 1996). Although adult ITP is often characterized by chronically depressed platelets, resistance to therapy, and a significant risk of hemorrhagic complications, a small percent of adult disease may be caused by an antecedent viral infection and be characterized by spontaneous recovery of platelet counts (Neylon et al, 2002). Prior to the routine use of corticosteroids for ITP, some individuals had spontaneous remission while awaiting splenectomy (Watson-Williams et al, 1958). In these cases platelets rose within two weeks and normalized within one hundred days. The risk of bleeding and mortality of acute ITP is lower than in chronic disease (Cortelazzo et al, 1991). Like children, a subset of adults may have a self-limited form of ITP with a low risk of bleeding that does not require treatment. In a study of chronic ITP, more patients died from therapeutic complications than from bleeding in the setting of thrombocytopenia (Portielje et al, 2001). As the incidence of ITP rises with the aging population, the risk and benefits of treating all adult patients must be considered.

Incidence of idiopathic thrombocytopenic purpura among adults

Incidence of idiopathic thrombocytopenic purpura among adults

The Incidence of Idiopathic Thrombocytopenic Purpura in Adults Increases With Age

With the aim of determining the incidence of idiopathic thrombocytopenic purpura (ITP) in adults, we searched all adult ITP patients diagnosed from April 1, 1973 to December 31, 1995 in the County of Funen in Denmark. This county comprises 9% of the total Danish adult population. A total of 221 patients fulfilled the inclusion criteria, yielding an annual standardized incidence rate of 2.68 per 100,000. The median age of the patient population was 56 years, and the female to male ratio was 1.7. Changing the platelet count cut-off point from 100 x 10(9)/L to 50 x 10(9)/L changed the incidence rate to 2.25 per 100,000. Comparing patients less and more than 60 years old, the incidence rate more than doubled and the sex difference was eliminated in the older age group. These two age groups were almost identical regarding platelet count at diagnosis and number of asymptomatic cases. The incidence rate increased in the study period. This increase in particular involved asymptomatic patients and old males who were both symptomatic or not symptomatic. Including additional patients identified by a questionnaire study of the contribution from the primary care physicians and the practicing specialists in the second half of the study period, a reliable estimate of the annual ITP incidence in Danish adults, using a platelet concentration cut-off point of 50 x 10(9)/L, is 3.2 per 100, 000 persons.

Diagnosis, clinical course, and management of idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura is a common acquired bleeding disorder. However, the diagnosis is often uncertain because there are no specific tests that define idiopathic thrombocytopenic purpura, and management decisions are often difficult because there are no firm data to define the clinical course and to estimate the risks of major bleeding and death. Because the incidence of idiopathic thrombocytopenic purpura is greatest in young women, its occurrence during pregnancy is a frequent problem, with specific issues related to the anticipated route of delivery and the risks for neonatal thrombocytopenia. To address these unresolved issues, the American Society of Hematology established a panel to develop a practice guideline for idiopathic thrombocytopenic purpura. The data from this recently published document and its recommendations are summarized in this review.

Childhood Idiopathic Thrombocytopenic Purpura: Report of 60 Cases from Kuwait

Sixty children with idiopathic thrombocytopenic purpura (ITP) were admitted to a regional hospital in Kuwait over a 6-year period. A high annual incidence of ITP (12.5/10(5] was noted, probably related to viral infections during the period of the study. Forty-one were patients with acute ITP and 19 with chronic ITP. The initial treatment varied: corticosteroids were given in 33 cases, no therapy in 23 cases, and intravenous gamma globulin (IVGG) in four cases. Splenectomy was carried out in two children, of whom one died 2 years later as a result of septicaemia. This study showed that conservative management can be adopted in mild cases of ITP and active measurements should be reserved for patients presenting with moderate-severe mucocutaneous bleeding and significant thrombocytopenia.