Julio del Río-Garma

Summary: Immune thrombotic thrombocytopenic purpura (iTTP) is an ultra‐rare disease that seldom occurs in the elderly. Few reports have studied the clinical course of iTTP in older patients. In this study, we have analysed the clinical characteristics at presentation and response to therapy in a series of 44 patients with iTTP ≥60 years at diagnosis from the Spanish TTP Registry and compared them with 209 patients with p = 0.008). Front‐line treatment in patients ≥60 years was like that administered in younger patients. Also, no evidence of a difference in clinical response and overall survival was seen in both groups. Of note, 14 and 25 patients ≥60 years received treatment with caplacizumab and rituximab, respectively, showing a favourable safety and efficacy profile, like that observed in patients <60 years.

The remission rate with plasma exchange (PE) in thrombotic thrombocytopenic purpura (TTP) exceeds 80%, but the disease relapses in up to 20-30% of the cases. Clinical characteristics and response to treatment of relapsed TTP are not well defined. The objective of the present study was to compare the clinical and biological characteristics at presentation and the response to treatment between de novo and relapsed TTP. For such purpose, a total of 102 episodes of idiopathic TTP (70 de novo and 32 relapses) included in a recent multicentric prospective cohort study were analysed. All patients were homogeneously treated with daily PE and costicosteroids. In comparison with de novo TTP, episodes of relapsed TTP showed a higher Hb level (median, 122 g/l versus 91 g/l, p < 0.001) and lower serum lactate dehydrogenase (2.2- versus 4.5-fold above the upper limit of normality, p < 0.001). Neurological symptoms and fever were less frequently observed in patients with relapsed TTP than in patients with de novo TTP. Patients with relapsed TTP needed fewer PE sessions (five versus ten, p = 0.02) and a smaller volume of plasma (221 ml/kg versus 468 ml/kg, p = 0.004) to achieve remission than those with de novo TTP. There was no significant difference in the rate of recrudescence under treatment, the need of complementary treatments or the frequency of refractoriness to PE therapy. In conclusion, relapsed TTP has a milder clinical profile and responds more easily to PE than de novo TTP.

Summary: Plasma exchange (PE) with plasma infusion is the treatment of choice for thrombotic thrombocytopenic purpura (TTP) but doubts remain as to whether all kinds of plasma are equally effective. A multicentric cohort study was conducted to compare methylene blue‐photoinactivated plasma (MBPIP) with quarantine fresh frozen plasma (qFFP) in the treatment of TTP. One hundred and two episodes of idiopathic TTP were included; MBPIP was used in 63 and qFFP in 39. The treatment schedule consisted of daily PE and costicosteroids, and the main end‐point was remission status on day 8. Patients treated with MBPIP required more PEs (median: 11 vs. 5, P = 0·002) and a larger volume of plasma (median: 485 ml/kg vs. 216 ml/kg, P = 0·007) to achieve a remission, and presented more recrudescences while on PE therapy (29 of 63 vs. 8 of 39, P = 0·02) than those receiving qFFP. After adjustment for possible confounding factors, the use of MBPIP was associated with a lower likelihood of remission on day 8 [Odds ratio (OR): 0·17; 95% confidence interval (CI): 0·06–0·47] and a higher risk of recrudescence while on treatment (OR: 4·2; 95% CI: 1·6–10·8). In conclusion, MBPIP is less effective than qFFP in the treatment of TTP.

Background and Objectives Methylene blue photo‐inactivated plasma (MBPIP) has been reported to be less effective than fresh‐frozen plasma (FFP) in the treatment of thrombotic thrombocytopenic purpura, which suggests a reduced content of the von Willebrand factor metalloprotease ADAMTS‐13 in MBPIP. Materials and Methods ADAMTS‐13 activity and von Willebrand factor antigen (vWF:Ag) levels were measured in plasma before and after photo‐oxidation by either the Springe method or a commercial ‘in house’ system as well as in cryoprecipitate‐poor plasma (CPP) and FFP (20 units each). Results Levels of ADAMTS‐13 activity in MBPIP processed by the Springe method or the commercial ‘in house’ system were comparable to one another and did not significantly differ from levels found in FFP [median (range): 114% (57–139%), 99% (74–123%), and 106% (70–130%), respectively]. ADAMTS‐13 activity was significantly reduced in CPP [median (range): 87% (70–107%) as compared with FFP (P < 0·05). Levels of vWF:Ag decreased after photo‐oxidation by both methods. Conclusion In vitro ADAMTS‐13 activity was conserved in MBPIP processed by the two photo‐oxidation methods analysed and did not significantly differ from levels found in FFP.

Background and Objectives  Plasma exchange with fresh‐frozen plasma (FFP) is the treatment of choice in thrombotic thrombocytopenic purpura (TTP). Methylene blue‐photoinactivated plasma (MBPIP) has been proposed as a safer alternative to FFP, but its effectiveness in the treatment of TTP is not well established. The purpose of this study was to investigate whether MBPIP is as effective as FFP in the treatment of TTP by plasma exchange.Materials and Methods  A retrospective analysis was carried out of 56 TTP episodes, occurring between 1990 and 2003, which had been treated by plasma exchange. MBPIP was used for fluid replacement in 27 episodes and FFP in 29. The effect of plasma (MBPIP or FFP) on treatment outcomes was analysed by multivariate logistic regression.Results  Compared to patients treated with FFP, those receiving MBPIP had an increased risk of dying from progressive TTP [adjusted odds ratio (OR) = 31; 95% confidence interval (CI): 1·2 to > 100], a greater number of recurrences while on plasma exchange therapy (OR = 4·6; 95% CI: 1·2–17), and a lower probability of attaining a sustained remission within 9 days of starting plasma exchange (OR = 5·2; 95% CI: 1·3–20).Conclusions  MBPIP seems to be less effective than FFP in the treatment of TTP. It is therefore prudent to avoid MBPIP until therapeutic equivalency to FFP has been established by randomized, controlled trials.