Patterns of care and burden of chronic idiopathic thrombocytopenic purpura in Brazil.

AIMS: Although several therapeutic options are available for chronic immune thrombocytopenic purpura (cITP), little is known about the treatment of cITP in Brazil. MATERIALS AND METHODS: A multi-center, retrospective chart review, observational study was designed to describe the treatment patterns, clinical burden, resources use, and associated costs for adult patients diagnosed with cITP and treated in public and private institutions in Brazil. Patient charts were screened in reverse chronological order based on their last visit post January 1, 2012. (All costs were calculated using 1.00 USD = 3.9571 BRL, from February 2016.) Results: Of 340 patient charts screened, 50 patients were eligible for inclusion in the study. Single-drug therapy (prednisone, dexamethasone, or dapsone) was the most commonly used treatment, followed by combination therapies (azathioprine + prednisone, azathioprine + prednisone + danazol, and prednisone + dapsone). Splenectomy was performed in 22% of patients after at least first-line treatment. Platelet count and number of bleeding episodes at diagnosis were 31,561.1/mm3 (SD = ±26,396.1) and 40 episodes, respectively; in first-line, 92,631.1/mm3 (SD = ±79,955.3) and 19 episodes, respectively; in second-line, 96,950.0/mm3 (SD = ±76,476.4) and 17 episodes, respectively. Private system patients had a higher median cost compared to public system patients (USD 17.49/month, range = 0-2,020.77 vs USD 9.51/month, range = 0-192.64, respectively). LIMITATIONS: This study does not allow conclusions for causal explanations due to the cohort study design, and treatment patterns represent only the practices of physicians who have agreed to participate in the study. CONCLUSIONS: The data indicate that available therapeutic strategies for second- and third-line therapies appear to be limited.

Structure-function analysis of the HrpB2-HrcU interaction in the Xanthomonas citri type III secretion system.

Bacterial type III secretion systems deliver protein virulence factors to host cells. Here we characterize the interaction between HrpB2, a small protein secreted by the Xanthomonas citri subsp. citri type III secretion system, and the cytosolic domain of the inner membrane protein HrcU, a paralog of the flagellar protein FlhB. We show that a recombinant fragment corresponding to the C-terminal cytosolic domain of HrcU produced in E. coli suffers cleavage within a conserved Asn264-Pro265-Thr266-His267 (NPTH) sequence. A recombinant HrcU cytosolic domain with N264A, P265A, T266A mutations at the cleavage site (HrcU(AAAH)) was not cleaved and interacted with HrpB2. Furthermore, a polypeptide corresponding to the sequence following the NPTH cleavage site also interacted with HrpB2 indicating that the site for interaction is located after the NPTH site. Non-polar deletion mutants of the hrcU and hrpB2 genes resulted in a total loss of pathogenicity in susceptible citrus plants and disease symptoms could be recovered by expression of HrpB2 and HrcU from extrachromossomal plasmids. Complementation of the ΔhrcU mutant with HrcU(AAAH) produced canker lesions similar to those observed when complemented with wild-type HrcU. HrpB2 secretion however, was significantly reduced in the ΔhrcU mutant complemented with HrcU(AAAH,) suggesting that an intact and cleavable NPTH site in HrcU is necessary for total functionally of T3SS in X. citri subsp. citri. Complementation of the ΔhrpB2 X. citri subsp. citri strain with a series of hrpB2 gene mutants revealed that the highly conserved HrpB2 C-terminus is essential for T3SS-dependent development of citrus canker symptoms in planta.