Acquired thrombotic thrombocytopenic purpura (TTP) frequently coexists with connective tissue disorders (CTDs), and this coexistence results in longer hospitalizations and higher hospital costs than in patients with TTP alone, according to study results published in the Journal of Clinical Medicine Research.

This retrospective study assessed data from the National Inpatient Sample (NIS) database for 14,400 patients with TTP diagnosed between 2009 and 2016. In total, 1247 patients (8.7%) had TTP with an underlying CTD.

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Of patients with TTP and underlying CTDs, 87.3% were female, compared with 64% of patients with TTP alone (P <.01). More black patients had TTP with a CTD compared with TTP alone (48.9% vs 39%; P <.01), while fewer white patients had both disorders compared with TTP alone (34.4% vs 47.3%; P< .01).

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Average age at presentation was significantly lower in patients with an underlying CTD compared with those without a CTD (43.9 years vs 48.6 years; P <.01). The burden of additional comorbidities was higher in patients with both TTP and CTDs, with 45.9% having more than 1 comorbidity, whereas 31% of patients without a CTD had more than 1 comorbidity (P <.01). A total of 53.9% of patients with both TTP and a CTD and 39.2% of patients with TTP but without CTD had private insurance (P <.01).

The results indicated no significant differences between the 2 patient groups regarding the size, location, or type of hospital where patients received care. Similarly, the time to initiate plasmapheresis was similar between the 2 groups, at 2.9 days in patients with underlying CTDs and 2.8 days in patients without underlying CTDs (P =.5499).

Patients with TTP and CTDs had a mean hospitalization of 18.2 days and mean inpatient stay cost of $76,166, whereas patients without a CTD had a mean hospitalization of 15.3 days and mean inpatient stay cost of $59,358 (P <.01). Nonetheless, the odds of inpatient mortality were similar in both patient groups.

No differences in risk for cardiac arrest, hemodialysis, acute coronary syndrome, the need for mechanical ventilation, or acute stroke were found between patients with and without underlying CTDs.


1.     Sharma P, Gurung A, Dahal S. Connective tissue disorders in patients with thrombotic thrombocytopenic purpura: a retrospective analysis using a national database [published online June 11, 2019]. J Clin Med Res. doi:10.14740/jocmr3850