Alemtuzumab-induced immune-mediated thrombotic thrombocytopenic purpura: A newly described drug-related autoimmune disease

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening disease that may result from drug exposure. We report a case of iTTP occurring in a 39-year-old patient, 45 months following introduction of the anti-CD52 lymphoid cell depleting monoclonal antibody alemtuzumab, to treat a relapsing-remitting multiple sclerosis. Treatment consisted in plasma exchange, corticosteroids and caplacizumab, allowing clinical remission 3 months after the diagnosis, attested by the absence of thrombocytopenia and recovery of ADAMTS-13 activity. As other autoimmune disorders, iTTP may occur following alemtuzumab. This diagnosis should be suspected in patients with features of thrombotic microangiopathy following this treatment.

A single scalp nodule as the first presentation of acute lymphoblastic leukemia (KMT2A::MLLT3) in a healthy-appearing infant: a case report

Background

Infant leukemia is a rare form of acute leukemia diagnosed prior to the age of 1 and is characterized by an extremely poor prognosis due to its dismal response to current therapeutic approaches. It comprises about 4% of all childhood cases of acute lymphoblastic leukemia (ALL). Isolated initial cutaneous involvement in ALL is uncommon, and even more so in infant ALL.

Case presentation

Here, we present the case of a 2-month-old healthy-appearing infant, initially presenting with a single scalp nodule and subsequently diagnosed with an infant ALL. The leukemia was characterized by the most immature B-lineage immunophenotype [pro-B ALL/B-I, according to the European Group for the Immunological Characterization of Leukaemias (EGIL) classification] and chromosomal translocation t(9;11)(p22;q23), resulting in fusion gene KMTLA2::MLLT3, which is considered a negative prognostic factor. The patient underwent hematopoietic stem cell transplantation and is still in remission.

Conclusions

This case is peculiar because of the rare occurrence of isolated initial cutaneous involvement in ALL. Despite the healthy appearance of the patient, every suspicious symptom suggestive of malignancies should be further investigated to anticipate the diagnosis and start treatment early.

A 52-week multicenter retrospective real-world study on effectiveness and safety of dupilumab in children with atopic dermatitis aged from 6 to 11 years

Background: Dupilumab has been shown to be a safe and effective drug for the treatment of atopic dermatitis (AD) in children from 6 months to 11 years in randomized clinical trials. Aim: The aim of this real-life study was to determine the effectiveness in disease control and safety of dupilumab at W52 in moderate-to-severe AD children aged 6-11 years.Methods: All data were collected from 36 Italian dermatological or paediatric referral centres. Dupilumab was administered at label dosage with an induction dose of 300 mg on day 1 (D1), followed by 300 mg on D15 and 300 mg every 4 weeks (Q4W). Treatment effect was determined as overall disease severity, using EASI, P-NRS, S-NRS and c-DLQI at baseline, W16, W24, and W52. Ninety-six AD children diagnosed with moderate-to-severe AD and treated with dupilumab were enrolled.Results: Ninety-one (94.8%) patients completed the 52-week treatment period and were included in the study. A significant improvement in EASI score, P-NRS, S-NRS and c-DLQI was observed from baseline to weeks 16, 24 and 52.Conclusions: Our real-life data seem to confirm dupilumab effectiveness and safety in paediatric patients. Moreover, our experience highlighted that patients achieving clinical improvement at W16 preserved this condition over time.

The somatic p.T81dup variant in AKT3 gene underlies a mild cerebral phenotype and expands the spectrum including capillary malformation and lateralized overgrowth

Heterozygous germline or somatic variants in AKT3 gene can cause isolated malformations of cortical development (MCDs) such as focal cortical dysplasia, megalencephaly (MEG), Hemimegalencephaly (HME), dysplastic megalencephaly, and syndromic forms like megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome, and megalencephaly-capillary malformation syndrome. This report describes a new case of HME and capillary malformation caused by a somatic AKT3 variant that differs from the common p.E17K variant described in literature. The patient's skin biopsy from the angiomatous region revealed an heterozygous likely pathogenic variant AKT3:c.241_243dup, p.(T81dup) that may affect the binding domain and downstream pathways. Compared to previously reported cases with a common E17K mosaic variant, the phenotype is milder and patients showed segmental overgrowth, an uncommon characteristic in AKT3 variant cases. These findings suggest that the severity of the disease may be influenced not only by the level of mosaicism but also by the type of variant. This report expands the phenotypic spectrum associated with AKT3 variants and highlights the importance of genomic analysis in patients with capillary malformation and MCDs.

Epidemiology of the disorders of the Pik3ca-related overgrowth spectrum (Pros)

PIK3CA pathogenic variants are responsible for a group of overgrowth syndromes, collectively known as PIK3CA-Related Overgrowth Spectrum (PROS). These gain-of-function variants arise postzygotically, and, according to time of onset, kind of embryonal tissue affected and regional body extension, give rise to heterogeneous phenotypes. PROS rarity and heterogeneity hamper the correct estimation of its epidemiology. Our work represents the first attempt to define the prevalence of PROS according to the established diagnostic criteria and molecular analysis and based on solid demographic data. We assessed the prevalence in Piedmont Region (Italy), including in the study all participants diagnosed with PROS born there from 1998 to 2021. The search identified 37 cases of PROS born across the 25-year period, providing a prevalence of 1:22,313 live births. Molecular analysis was positive in 81.0% of participants. Taking into account the cases with a detected variant in PIK3CA (n = 30), prevalence of molecularly positive PROS was 1:27,519.

Successful treatment with MEK-inhibitor in a patient with NRAS-related cutaneous skeletal hypophosphatemia syndrome

Cutaneous skeletal hypophosphatemia syndrome (CSHS) is caused by somatic mosaic NRAS variants and characterized by melanocytic/sebaceous naevi, eye, and brain malformations, and FGF23-mediated hypophosphatemic rickets. The MEK inhibitor Trametinib, acting on the RAS/MAPK pathway, is a candidate for CSHS therapy. A 4-year-old boy with seborrheic nevus, eye choristoma, multiple hamartomas, brain malformation, pleural lymphangioma and chylothorax developed severe hypophosphatemic rickets unresponsive to phosphate supplementation. The c.182A > G;p.(Gln61Arg) somatic NRAS variant found in DNA from nevus biopsy allowed diagnosing CSHS. We administered Trametinib for 15 months investigating the transcriptional effects at different time points by whole blood RNA-seq. Treatment resulted in prompt normalization of phosphatemia and phosphaturia, catch-up growth, chylothorax regression, improvement of bone mineral density, reduction of epidermal nevus and hamartomas. Global RNA sequencing on peripheral blood mononucleate cells showed transcriptional changes under MEK inhibition consisting in a strong sustained downregulation of signatures related to RAS/MAPK, PI3 kinase, WNT and YAP/TAZ pathways, reverting previously defined transcriptomic signatures. CSHS was effectively treated with a MEK inhibitor with almost complete recovery of rickets and partial regression of the phenotype. We identified "core" genes modulated by MEK inhibition potentially serving as surrogate markers of Trametinib action.

Lateralized overgrowth with vascular malformation caused by a somatic PTPN11 pathogenic variant: another piece added to the puzzle of mosaic RASopathies

Lateralized/segmental overgrowth disorders (LOs) encompass a heterogeneous group of congenital conditions with excessive body tissue growth. Documented molecular alterations in LOs mostly consist of somatic variants in genes of the PI3KCA/AKT/mTOR pathway or of chromosome band 11p15.5 imprinted region anomalies. In some cases, somatic pathogenic variants in genes of the RAS/MAPK pathway have been reported. We present the first case of a somatic pathogenic variant (T507K) in PTPN11 causing a LO phenotype characterized by severe lateralized overgrowth, vascular proliferation, and cerebral astrocytoma. The T507K variant was detected in DNA from overgrown tissue in a leg with capillary malformation. The astrocytoma tissue showed a higher PTPN11 variant allele frequency. A pathogenic variant in FGFR1 was also found in tumor tissue, representing a second hit on the RAS/MAPK pathway. These findings indicate that RAS/MAPK cascade overactivation can cause mosaic overgrowth phenotypes resembling PIK3CA‐related overgrowth disorders (PROS) with cancer predisposition and are consistent with the hypothesis that RAS/MAPK hyperactivation can be involved in the pathogenesis of astrocytoma. This observation raises the issue of cancer predisposition in patients with RAS/MAPK pathway gene variants and expands genotype spectrum of LOs and the treatment options for similar cases through inhibition of the RAS/MAPK oversignaling.

Kaposiform hemangioendothelioma further broadens the phenotype of PIK3CA-related overgrowth spectrum

Kaposiform hemangioendothelioma (KHE) is a rare locally aggressive mixed vascular tumor, with typical onset in early childhood and characterized by progressive angio- and lymphangiogenesis. Its etiopathogenesis and molecular bases are still unclear. Here, we report the first case of congenital KHE harboring a PIK3CA mosaic pathogenic variant (c.323G > A, p.Arg108His) in a boy with very subtle PIK3CA-related overgrowth spectrum (PROS) features. This finding provides insights into the pathophysiology of KHE, offering targeted therapeutic options by inhibition of the PI3K/Akt/mTOR pathway. We propose the inclusion of this mixed lymphatic and vascular anomaly within the PROS.

Factors associated with tuberculosis-associated haemophagocytic syndrome: a multicentre case-control study

SETTING: Tuberculosis (TB) is a potential trigger of haemophagocytic syndrome (HS) but little is known about the features of TB-associated HS.OBJECTIVE: To assess the risk factors associated with HS in patients with TB.DESIGN: We performed a multicentre case-control study assessing the medical records of adult patients diagnosed with proven TB with (TB/HS+) or without (TB/HS-) associated HS.RESULTS: Twenty-one patients with TB/HS+ (24% women, median age, 37 years [IQR 30-48]) were included in the study. Eleven patients (52%) were infected with human immunodeficiency virus and seven patients (33%) were immunocompromised due to other reasons. TB was disseminated in 17 patients (81%). Compared with 50 control TB patients (TB/HS-), patients with TB/HS+ were more likely to be immunocompromised (86% vs. 18%; P < 0.001) and to present with disseminated TB (80% vs. 12%; P < 0.001). The outcome was poorer in patients with TB/HS+, with a higher admission rate to intensive care (71% vs. 0%; P < 0.001) and a higher risk of death (38% vs. 7%; P = 0.005).CONCLUSION: TB/HS+ occurred more likely in immunocompromised patients and severely impaired the prognosis of TB. Further studies are needed to devise therapeutic strategies for patients with TB/HS+.

A new case of Smith-Kingsmore syndrome with somatic MTOR pathogenic variant expands the phenotypic spectrum to lateralized overgrowth

Smith-Kingsmore syndrome (SKS) is a rare autosomal dominant disorder caused by heterozygous germline activating pathogenic variants in mammalian target of rapamycin (MTOR) on chromosome 1p36. A few patients with disseminated mosaicism have been described so far and they seem to display a different phenotype when compared to germline cases. Here we report the sixth case with a disseminated mosaic MTOR pathogenic variant, a 7-year-old boy with hemimegalencephaly, epilepsy, developmental delay, hypomelanosis of Ito, and lateralized overgrowth. Genetic testing revealed a pathogenic variant (c.4448G > A, p.Cys1483Tyr) in MTOR with a frequency of 32% in the DNA extracted from a skin sample, 3% in saliva and 0.46% in blood. The clinical features observed in our patient further corroborate the existence of differences in phenotypic presentation of germline and mosaic SKS cases. Moreover, lateralized overgrowth, a finding never described so far in SKS, further expands the phenotypic spectrum of SKS and allows the inclusion of MTOR pathogenic variants among the several causes of asymmetric body overgrowth.

[Endothelial dysfunction in thrombotic thrombocytopenic purpura: therapeutic perspectives]

Immune Thrombotic Thrombocytopenic Purpura (iTTP) is a rare but severe disease with a mortality rate of almost 100 % in the absence of adequate treatment. iTTP is caused by a severe deficiency in ADAMTS13 activity due to the production of inhibitory antibodies. Age has been shown to be a major prognostic factor. iTTP patients in the elderly (60yo and over) have more frequent organ involvement, especially heart and kidney failures compared with younger patients. They also have non-specific neurologic symptoms leading to a delayed diagnosis. Factors influencing this impaired survival among older patients remain unknown so far. Alteration of the functional capacity of involved organs could be part of the explanation as could be the consequences of vascular aging. In fact, severe ADAMTS13 deficiency is necessary but likely not sufficient for iTTP physiopathology. A second hit leading to endothelial activation is thought to play a central role in iTTP. Interestingly, the mechanisms involved in endothelial activation may share common features with those involved in vascular aging, potentially leading to endothelial dysfunction. It could thus be interesting to better investigate the causes of mid- and long-term mortality among older iTTP patients to confirm whether inflammation and endothelial activation really impact vascular aging and long-term mortality in those patients, in addition to their presumed role at iTTP acute phase. If so, further insights into the mechanisms involved could lead to new therapeutic targets.

Prognosis of Lymphoma in Patients With Known Inflammatory Bowel Disease: A French Multicentre Cohort Study

BACKGROUND AND AIMS

The prognosis of lymphoma that occurs in patients with inflammatory bowel disease [IBD] is poorly known.

METHODS

A multicentre retrospective cohort analysis was done in seven French tertiary centres from 1999 to 2019. Only lymphoma occurring in patients with previous established diagnosis of IBD were analysed. The primary outcome was progression-free survival at 3 years.

RESULTS

A total of 52 patients [male 65%, Crohn's disease 79%, median age 48.3 years, median duration of IBD 10.1 years] were included, of whom 37 had been previously exposed to immunosuppressants and/or biologics for at least 3 months and 20 had primary intestinal lymphomas. The lymphoma histological types were: diffuse large B cell lymphomas [N = 17], Hodgkin lymphomas [N = 17], indolent B cell lymphomas [N = 12], and others including T cell lymphomas, mantle cell lymphomas, and unclassifiable B cell lymphoma [N = 6]. The median follow-up after lymphoma was 5.1 years (interquartile range [IQR] 4-7.8). Progression-free survival at 3 years was 85% in the overall population (95% confidence interval [CI] 75%-96%) with no significant difference between the exposed and unexposed group, 79% for patients exposed to immunosuppressants and/or biologics [95% CI 67%-94%], and 83% for patients diagnosed with primary intestinal lymphoma [95% CI 67%-100%]. No relapse of IBD has been observed during chemotherapy. The IBD relapse rate at the end of the last chemotherapy cycle was 23% at 3 years [95% CI 11%-39%] in the overall population.

CONCLUSIONS

In this large cohort, the prognosis for lymphomas occurring in IBD appears to be good and similar to what is expected, irrespective of the exposure to biologics and/or immunosuppressants.

Caplacizumab to treat immune-mediated thrombotic thrombocytopenic purpura

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening disease characterized by microangiopathic hemolytic anemia, thrombocytopenia and multiorgan failure, resulting from autoantibody-mediated severe A disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13) deficiency. In spite of treatment with plasma exchange and immunosuppression, patients remain at risk of exacerbations, refractoriness and death. Caplacizumab (Cablivi; Ablynx, a Sanofi company), a nanobody targeting von Willebrand factor (vWF), has been recently approved in the E.U. and the U.S. as the first therapeutic specifically indicated for the treatment of adults experiencing an episode of iTTP. Caplacizumab blocks the interaction of all multimers with platelets and, therefore, has an immediate effect on platelet aggregation and the ensuing formation and accumulation of platelet-rich microthrombi. This immediate effect of caplacizumab has the potential to protect the patient from tissue ischemia and organ dysfunction while the underlying disease process resolves. We detail here the preclinical and clinical data on caplacizumab for iTTP, including the recent studies that led to approval by the U.S. Food and Drug Administration (FDA) in 2019.

Plasma for direct therapeutic use, for today and tomorrow: A short critical overview

Plasma for direct therapeutic use is a fast-evolving blood component in terms of its production and presentation. More than a dozen forms are available worldwide, which is often overlooked since most countries apply policies making only one or very few forms available for treating patients in need. It is most often reserved for the same three clinical indications, i.e. overall clotting-factor deficiency, reversal of vitamin K antagonists in the context of active bleeding or prior to urgent surgery, and therapeutic plasma exchange. The level of evidence is often less robust than generally acknowledged for such major indications while novel indications are tending to emerge in medical and trauma settings. This short review explores classical views and new prospects opened up by novel presentations and statuses for therapeutic plasma.

An open conformation of ADAMTS-13 is a hallmark of acute acquired thrombotic thrombocytopenic purpura

Essentials Conformational changes in ADAMTS-13 are part of its mode-of-action. The murine anti-ADAMTS-13 antibody 1C4 discriminates between folded and open ADAMTS-13. ADAMTS-13 conformation is open in acute acquired thrombotic thrombocytopenic purpura (TTP). Our study forms an important basis to fully elucidate the pathophysiology of TTP.

SUMMARY

Background Acquired thrombotic thrombocytopenic purpura (aTTP) is an autoimmune disorder characterized by absent ADAMTS-13 activity and the presence of anti-ADAMTS-13 autoantibodies. Recently, it was shown that ADAMTS-13 adopts a folded or an open conformation. Objectives As conformational changes in self-antigens play a role in the pathophysiology of different autoimmune diseases, we hypothesized that the conformation of ADAMTS-13 changes during acute aTTP. Methods Antibodies recognizing cryptic epitopes in the spacer domain were generated. Next, the conformation of ADAMTS-13 in 40 healthy donors (HDs), 99 aTTP patients (63 in the acute phase versus 36 in remission), 12 hemolytic-uremic syndrome (HUS) patients and 63 sepsis patients was determined with ELISA. Results The antibody 1C4 recognizes a cryptic epitope in ADAMTS-13. Therefore, we were able to discriminate between a folded and an open ADAMTS-13 conformation. We showed that ADAMTS-13 in HDs does not bind to 1C4, indicating that ADAMTS-13 circulates in a folded conformation. Similar results were obtained for HUS and sepsis patients. In contrast, ADAMTS-13 of acute aTTP patients bound to 1C4 in 92% of the cases, whereas, in most cases, this binding was abolished during remission, showing that the conformation of ADAMTS-13 is open during an acute aTTP episode. Conclusions Our study shows that, besides absent ADAMTS-13 activity and the presence of anti-ADAMTS-13 autoantibodies, an open ADAMTS-13 conformation is also a hallmark of acute aTTP. Demonstrating this altered ADAMTS-13 conformation in acute aTTP will help to further unravel the pathophysiology of aTTP and lead to improved therapy and diagnosis.

Expression of miRNA 155, FOXP3 and ROR gamma, in children with moderate and severe atopic dermatitis

BACKGROUND

Atopic dermatitis is a disease characterized by a chronic inflammatory process in the skin, but its link to miRNA 155 is less known. The aim of the study was to evaluate the expression of microRNA155, and T helper type 17 cells and Treg cells in children with atopic dermatitis.

METHODS

The study population consisted of: children seen for atopic dermatitis at the outpatient ambulatory of Dermatology at the Children Hospital Regina Margherita, Torino, Italy (N.=23); healthy control subjects (N.=23). Blood samples were taken during routine control analysis and the expression of miRNA 155 and the production of FOXP3 and RORγ was determined using PCR real time.

RESULTS

The analysis of miR-155 shows that the over-expression of miR-155 is statistically significant (P=0.0040) in the group of patients with atopic dermatitis compared to the healthy control group. Analysis of mRNAs of FOXP3 and RORγ shows a FOXP3 mRNA expression statistically higher in the group of patients (P=0.0057). The Th17 / Treg ratio is significantly smaller in patients with atopic dermatitis (P=0.0012). Also the ratio miR-155/Th17/Treg is larger in the group of patients with atopic dermatitis (P=0.0002).

CONCLUSIONS

Our results suggest that increased miR-155 and FOXP3 and RORγ responses may provide a link to immune dysregulation associated with atopic dermatitis. Although a point-by-point correlation between miR-155 and the ratio Th17/Treg is not demonstrated, our findings shows that these two elements do not appear to be completely unrelated to each other.

Amplified endogenous plasmin activity resolves acute thrombotic thrombocytopenic purpura in mice

Essentials Plasmin is able to proteolyse von Willebrand factor. It was unclear if plasmin influences acute thrombotic thrombocytopenic purpura (TTP). Plasmin levels are increased during acute TTP though suppressed via plasmin(ogen) inhibitors. Allowing amplified endogenous plasmin activity in mice results in resolution of TTP signs.

SUMMARY

Background Thrombotic thrombocytopenic purpura (TTP) is an acute life-threatening pathology, caused by occlusive von Willebrand factor (VWF)-rich microthrombi that accumulate in the absence of ADAMTS-13. We previously demonstrated that plasmin can cleave VWF and that plasmin is generated in patients during acute TTP. However, the exact role of plasmin in TTP remains unclear. Objectives Investigate if endogenous plasmin-mediated proteolysis of VWF can influence acute TTP episodes. Results In mice with an acquired ADAMTS-13 deficiency, plasmin is generated during TTP as reflected by increased plasmin-α2-antiplasmin (PAP)-complex levels. However, mice still developed TTP, suggesting that this increase is not sufficient to control the pathology. As mice with TTP also had increased plasminogen activator inhibitor 1 (PAI-1) levels, we investigated whether blocking the plasmin(ogen) inhibitors would result in the generation of sufficient plasmin to influence TTP outcome in mice. Interestingly, when amplified plasmin activity was allowed (α2-antiplasmin-/- mice with inhibited PAI-1) in mice with an acquired ADAMTS-13 deficiency, a resolution of TTP signs was observed as a result of an increased proteolysis of VWF. In line with this, in patients with acute TTP, increased PAP-complex and PAI-1 levels were also observed. However, neither PAP-complex levels nor PAI-1 levels were related to TTP signs and outcome. Conclusions In conclusion, endogenous plasmin levels are increased during acute TTP, although limited via suppression through α2-antiplasmin and PAI-1. Only when amplified plasmin activity is allowed, plasmin can function as a back-up for ADAMTS-13 in mice and resolve TTP signs as a result of an increased proteolysis of VWF.

Amotosalen-inactivated plasma is as equally well tolerated as quarantine plasma in patients undergoing large volume therapeutic plasma exchange

A retrospective - single center - survey compared tolerance of individual donor therapeutic plasma in a series of 88 patients principally presenting with thrombotic microangiopathy; all patients underwent therapeutic plasma exchange (TPE) performed with more than 90% of either of two types of plasma preparations. One plasma type used in TPE was prepared with pathogen reduction by amotosalen addition and UVA illumination, and the other one was non-manipulated (quarantine plasma). Both types of plasma were single donor. Occurrences of adverse reactions were equally low in either arm (amotosalen: 9 in 4689 bags of ∼200mL [0.019] versus quarantine: 2 in 828 bags [0.024]), confirming the safe use of amotosalen inactivated therapeutic plasma for TPE.

[Secondary thrombotic microangiopathies]

Thrombotic microangiopathies (TMA) are termed secondary when associated to a specific context favouring their occurrence. They encompass mainly TMA associated with pregnancy, allogeneic hematopoietic stem cell transplantation, cancer, drugs, or HIV infection. Secondary TMA represent a heterogeneous group of diseases which clinical presentation largely depends on the associated context. It is therefore mandatory to recognize these conditions since they have a significant impact in TMA management and prognosis. A successful management still represents a challenge in secondary TMA. Significant progresses have been made in the understanding of pregnancy-associated TMA, allowing an improvement of prognosis; on the opposite, other forms of secondary TMA such as hematopoietic stem cell transplantation-associated TMA or TMA associated with chemotherapy remain of dismal prognosis. A better understanding of pathophysiology in these forms of TMA, in association with a more empirical approach through the use of new therapeutic agents that can also help in the understanding on new mechanisms a posteriori, should improve their prognosis. The preliminary encouraging results reported with complement blockers in this field could represent a convincing example.

[Hemolytic and uremic syndrome and related thrombotic microangiopathies: Epidemiology, pathophysiology and clinics]

Thrombotic microangiopathies (TMA) represent an eclectic group of conditions, which share hemolytic anemia and thrombocytopenia as a common defining basis. Remarkable breakthroughs in the physiopathological setting have allowed for a thorough recomposition of the disparate syndromes, which form the constellation of TMA. In this view, clinicians now discriminate thrombocytopenic thrombotic purpura (TTP) defined by a severe deficiency in ADAMTS13, which is rarely associated with a severe renal involvement and the hemolytic and uremic syndrome (HUS) in which renal impairment is the most prominent clinical feature. HUS can result from toxins stemming from bacterial infections of the digestive tract, alternate complement pathway abnormalities, metabolic or coagulation disorders or, lastly, drug and various toxic compounds. The diverse forms of HUS reflect the insights gained in the understanding of the pathophysiological mechanisms underpinning TMA. In this first part, a broad overview of the epidemiological, physiopathological and clinical aspects of HUS and related TMA syndromes is presented.

Management of thrombotic thrombocytopenic purpura

Daily therapeutic plasma exchange (TPE) transformed the historically fatal prognosis of acquired, anti-ADAMTS13 antibody-mediated thrombotic thrombocytopenic purpura (TTP), leading to the current overall survival rates of >80%. However, relapses occur in up to 40% of patients and refractory disease with fatal outcomes still occurs, typically within the first days of management. In this context, the introduction of rituximab has been the second major breakthrough in TTP management. Rituximab is now routinely recommended during the acute phase, typically in patients with a suboptimal response to treatment, and increasingly as frontline therapy, with high response rates in the following weeks. In more severe patients, salvage strategies typically include twice daily TPE, pulses of cyclophosphamide, as well as splenectomy in the more desperate cases. In this life-threatening and debilitating disease, relapses can be efficiently prevented in patients with a severe acquired ADAMTS13 deficiency and otherwise in remission with the use of rituximab. In the coming years, the TTP therapeutic landscape should be enriched by original strategies stemming from clinical experience and new agents that are currently being evaluated in large, international, clinical trials. Promising agents under evaluation include caplacizumab (an inhibitor of the glycoprotein-Ib/IX-Von-Willebrand factor axis), N-acetylcysteine, recombinant ADAMTS13, and anti-plasmocyte compounds.

Clinical characteristics and prognostic factors of plasmablastic lymphoma patients: analysis of 135 patients from the LYSA group

Background

Plasmablastic lymphoma (PBL), initially described in 1997 in the oral cavity of HIV positive patients, is now recognized as a distinct aggressive and rare entity of diffuse large B-cells lymphoma by the World Health Organization (WHO) classification. Since the original description, others cases have been reported. However, these are largely derived from case reports or small series limiting any definitive conclusions on clinical characteristics and outcome.

Patients and methods

The clinical, biological, pathological features and outcome of a cohort including 135 patients with PBL, from LYSA centers in France and Belgium, were reported and analyzed.

Results

The median age was 58 years, with a male predominance. The cohort was divided into 56 HIV-positive patients, 17 post-transplant patients and 62 HIV-negative/non-transplanted patients. Within HIV-negative/non-transplanted, a relative immunosuppression was found in most cases (systemic inflammatory disease, history of cancer, increased age associated with weakened immune system). We have also described a new subtype, PBL arising in a chronic localized inflammatory site, without any sign of immunosuppression. At presentation, 19% of patients showed oral involvement. Immunophenotype showed CD138 positivity in 88% of cases and CD20 negativity in 90% of cases. Chemotherapy was administered to 80% of patients, with a complete response (CR) rate of 55%. The median overall survival (OS) was 32 months. In univariate analysis, HIV positive status showed better OS when compared with HIV negative status. In multivariate analysis, International Prognostic Index score, chemotherapy and CR were associated with survival benefit.

Conclusion(s)

This cohort, the largest reported to date, increases the spectrum of knowledge on PBL, rarely described. However, specific guidelines to clarify treatment are lacking, and may improve the poor prognosis of this rare disease.

Three case reports of post immunization and post viral Bullous Pemphigoid: looking for the right trigger

Background

Bullous pemphigoid (BP) is a blistering skin disorder infrequent in infancy and rarely reported in medical literature.

Case Presentation

Here we describe three cases of BP which were referred to our department in the last 15 years. Two of them developed an eruption of bullous lesions just a few days after vaccination for diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B and Haemophilus influenzae B. The third patient developed the same blistering lesions shortly after herpetic stomatitis. In all three cases, clinical diagnosis was confirmed by histological examination which showed subepidermal bullae with a dermal inflammatory infiltrate, and direct immunofluorescence of perilesional skin showed linear IgG and C3 deposits along the basement membrane zone. Immunoblot assay was positive for BP antigen 180. Treatment with oral prednisone was instituted and the lesions resolved in two out of three patients; the third one was treated with an immunosuppressive agent (tacrolimus) and corticosteroid and subsequently with intravenous immunoglobulin and plasmapheresis, due to an underlying complex autoimmune disease.

Conclusion

Although the mechanism of induction of BP is still unclear, the close relationship between trigger events (immunization or viral infection) and onset of the disease arises a possible association.

Consensus on the standardization of terminology in thrombotic thrombocytopenic purpura and related thrombotic microangiopathies

Essentials An international collaboration provides a consensus for clinical definitions. This concerns thrombotic microangiopathies and thrombotic thrombocytopenic purpura (TTP). The consensus defines diagnosis, disease monitoring and response to treatment. Requirements for ADAMTS-13 are given.

SUMMARY

Background Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) are two important acute conditions to diagnose. Thrombotic microangiopathy (TMA) is a broad pathophysiologic process that leads to microangiopathic hemolytic anemia and thrombocytopenia, and involves capillary and small-vessel platelet aggregates. The most common cause is disseminated intravascular coagulation, which may be differentiated by abnormal coagulation. Clinically, a number of conditions present with microangiopathic hemolytic anemia and thrombocytopenia, including cancer, infection, transplantation, drug use, autoimmune disease, and pre-eclampsia and hemolysis, elevated liver enzymes and low platelet count syndrome in pregnancy. Despite overlapping clinical presentations, TTP and HUS have distinct pathophysiologies and treatment pathways. Objectives To present a consensus document from an International Working Group on TTP and associated thrombotic microangiopathies (TMAs). Methods The International Working Group has proposed definitions and terminology based on published information and consensus-based recommendations. Conclusion The consensus aims to aid clinical decisions, but also future studies and trials, utilizing standardized definitions. It presents a classification of the causes of TMA, and criteria for clinical response, remission and relapse of congenital and immune-mediated TTP.