Patterns of Clinical Presentation of Thrombotic Thromboxytopenic Purpura. Is There a Racial Difference?. A Single Institution Experience.)

Thrombotic thrombocytopenic purpura (TTP) is a rare but serious disease that has been reported more frequently in African-Americans (AA). While recent reports have showed an increased incidence of TTP amongs AA patients, there is no data with regards to the patterns of clinical presentation in this racial subgroup and if there is any difference as compared to other racial subgroups.

In this retrospective study we reviewed characterstics and clinical presentation of 91 patients with the diagnosis of TTP. Sixty four patients were AAs (70%). The second largest racial subgroup was Caucasians (24 patients, 26%). Demographics, lab values and symptoms were compared between AAs and Caucasians. Continuous variables were compared using two-sided two-sample t-tests. Alternatively, the Wilcoxon rank-sum test was used if the data were not normally distributed. Categorical variables were compared using Chi-square tests.

AA patients were older [median age of 47.6 years as compared to 40 years, P-value of 0.057] and more likely to be females [68.8%, (n=44/64) as compared to 45.8%, (n=11/24), P-value of 0.048]. As for laboratory evaluation, AA patients were more likely to have positive ANA [44% (n=22/64) as compared to 14.3% (n=2/24), P-value of 0.042] and higher ESR (median of 75.5 as compared to 40.7, P-value 0.03). Other laboratory evaluation including hemoglobin, platelet counts and creatinine were comparable. The most common patterns of clinical presentation in AA patients were in the form of constitutional symptoms (fatigue, malaise and generalized weakness) which were seen in 67% of patients (n=43), followed by neurological symptoms (mainly headache and confusion) in 53% of pateints (n=34). Gastrointestinal (GI) symptoms (nausea, vomiting or abdominal pain) were seen in 44% of patients (n=28). This pattern was comparable to what is seen in Caucasian patients. Skin symptoms were reported less frequently in AA as compared to Caucasians (17.2% vs. 41.7%, p = 0.016).

While AA patients are more likely to be females, older and have positive ANA, the clinical presentation of TTP is similar among different racial subgroups (African Americans and Caucasians).

No relevant conflicts of interest to declare.