August 2026 Research Update

Across this group, the main direction was toward ADAMTS13 testing that is either faster (closer to the bedside) or more informative (adding antibody or protein-shape information), alongside updated laboratory guidance on how to run and interpret these tests. Some approaches are early-stage and still need broader clinical validation, especially for how well they perform in different hospitals and patient groups. [1] [2] [3] [4]

One proof-of-principle validation study tested a portable, microfluidic, luminescence-based ADAMTS13 activity assay using 39 biobank samples and found its activity results generally matched two commercial reference methods. It also demonstrated a way to detect inhibitory anti-ADAMTS13 antibodies in the same cartridge, with an analytical turnaround time of about 30 minutes, but the authors noted it is not yet ready for true near-patient use and needs further clinical validation. [1]

A separate retrospective study in 25 Japanese patients with acute immune-mediated TTP measured whether ADAMTS13 was in an "open" versus "closed" shape using a patient IgG-based test. The IgG-based approach identified an open conformation in all patients at presentation, including when ADAMTS13 antigen levels were too low for a conventional conformation test, and in follow-up 4 of 5 people who relapsed showed an open conformation beforehand in both assays. [2]

A British Society for Haematology guideline focused on laboratory methods for diagnosing and monitoring TTP, centered on how laboratories test for ADAMTS13 deficiency. This paper reinforces that the testing pathway matters, not only the test name, because laboratories may differ in methods and workflows. [3]

One case-control study explored whether simple ratios derived from a complete blood count (such as neutrophil-to-lymphocyte ratio) differed between 114 TTP patients and 115 healthy controls. The ratios were different in patients versus controls, but the authors framed these measures as possible adjuncts that require confirmation in larger, prospective studies, rather than replacements for ADAMTS13 testing. [4]

For patients and caregivers, these papers mainly describe how testing may become faster and more informative over time, potentially helping teams distinguish immune-mediated from inherited disease and monitor risk of relapse. For now, the newer device-based activity test and the IgG-based conformation test are still supported by limited study sizes and need more validation before their role is clear in everyday care. The guideline underscores that high-quality lab processes remain central, while blood-count ratios are best viewed as background research until they are tested in prospective, real-world settings. [1] [2] [3] [4]

Across this group, the strongest evidence came from a small real-world study suggesting that adding caplacizumab to standard treatment for immune-mediated thrombotic thrombocytopenic purpura (iTTP) can speed blood count recovery and shorten the overall time to remission. Evidence about rituximab and relapse prevention was less certain in this dataset, and individual case reports highlighted that treatment plans may be shaped by how iTTP shows up in a particular person. [5] [6]

In a single-center retrospective study of 30 adults (46 acute episodes), caplacizumab use was linked to faster clinical response and faster remission compared with episodes not receiving caplacizumab, and it also reduced the number of plasma exchange sessions. When caplacizumab was started earlier (within 72 hours), hospital stay was shorter in that report. [5]

In the same study, rituximab use showed a lower relapse percentage, but the difference was not statistically significant, meaning the study could not clearly rule out chance as an explanation. When caplacizumab and rituximab were both added to steroids and plasma exchange ("quadruple therapy"), time to clinical remission was shorter than with steroids and plasma exchange alone, with fewer plasma exchange sessions. [5]

One case report described a 37-year-old woman whose iTTP mainly showed up with neuropsychiatric symptoms; treatment with high-dose corticosteroids, urgent plasma exchange, and rituximab was followed by rapid remission and full neurologic recovery. Because this is a single patient, it cannot show how often the same result would happen for others. [6]

For patients and caregivers, these papers mainly add context about how iTTP treatment can be intensified beyond steroids and plasma exchange in some settings, and what changes were seen in one center's experience (faster response and fewer plasma exchange sessions with caplacizumab). What remains uncertain is how much relapse risk changes with rituximab in broader patient groups and how results compare across different hospitals, since the key study was small, retrospective, and from a single center.

These papers looked at plasma-removal treatments used in hospital settings: standard therapeutic plasma exchange delivered with a membrane-based system in many conditions, and a specialized form (lymphoplasmapheresis) described in a single, complex lupus-related iTTP case. Overall, the evidence suggests these procedures can be delivered with complications that were usually treated without stopping the procedure, but the iTTP-specific evidence here is limited and does not compare approaches head-to-head. [7] [8]

In an eight-year, single-center retrospective cohort (131 patients, 967 sessions) using membrane plasma separation based therapeutic plasma exchange, complications were reported per session, with no deaths and no procedures abandoned. Among patients grouped as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, clinician-assessed responses included both complete and partial responses, but there was no control group and no long-term outcome reporting. [7]

One case report described a 30-year-old man with systemic lupus erythematosus (SLE) associated iTTP and brain involvement (lupus cerebritis) whose disease did not improve with standard therapeutic plasma exchange. After an optimized lymphoplasmapheresis sequence, his platelet count normalized, brain MRI lesions steadily shrank, kidney measures improved, and ADAMTS13 activity increased to 87%. Because this is one patient, it shows what was possible in a single situation rather than what is typical. [8]

For patients, this theme is mostly background about the hospital procedures that may be used to remove harmful proteins from blood in iTTP and related immune conditions, and what short-term safety issues were reported in one center's membrane-based program. The case report suggests that, in a rare and complicated lupus-related situation, a specialized procedure was used after standard exchange did not work, but it is not clear how often this approach is available, appropriate, or effective for others without larger studies.

Across two single-patient reports, thrombotic thrombocytopenic purpura (TTP) appeared in the setting of advanced cancer, either as a paraneoplastic complication of the cancer itself or after cancer drug treatment. Both reports emphasized that sorting out the cause can be difficult when multiple possible triggers are present; in the lung cancer case, very low ADAMTS13 activity and an ADAMTS13 inhibitor supported the diagnosis. [9] [10]

In one person with stage IVB lung adenocarcinoma, acquired immune TTP occurred after a regimen that included ivonescimab, along with severe cholestatic liver injury and a temporary but severe acute kidney injury that required continuous dialysis support. The diagnosis was supported by very low ADAMTS13 activity with an ADAMTS13 inhibitor, and the authors noted they could not prove which drug (or the cancer itself) was the main trigger because the regimen included multiple treatments and no organ biopsies were done. [9]

That lung cancer case described recovery of kidney function and improvement in liver blood tests after plasma-based procedures and immune-suppressing medicines, while a specific anti-clotting antibody (caplacizumab) was not used because it was not available. The paper also included a focused literature review of previously reported TTP linked to immune checkpoint inhibitors (immunotherapy drugs such as PD-1 blockers), and noted that VEGF-blocking drugs can separately injure small blood vessels in the kidney. [9]

A separate intensive care report described paraneoplastic TTP in a patient with metastatic prostate cancer and highlighted diagnostic challenges when different mechanisms may contribute to low platelets and organ problems. It also discussed that treatment options can differ depending on the type of TTP, including the role of plasma exchange in paraneoplastic TTP. [10]

For patients and caregivers, these reports mainly serve as background information that TTP can rarely occur alongside advanced cancers or around the time of cancer drug therapy, and it may come with serious organ complications such as liver injury or kidney failure. Because both papers describe single patients, they cannot show how often this happens or which cancer treatments are most likely to be involved, and they underscore that it is not always possible to pinpoint the exact trigger when cancer and multiple medications overlap.

Across this month's evidence, the main message is that thrombotic thrombocytopenic purpura (TTP) after childbirth can look like other pregnancy-related conditions at first. In one reported patient, the diagnosis became clearer when blood abnormalities continued after delivery and a specific blood test pattern supported immune TTP. [11]

This single case report described a woman who was initially thought to have HELLP syndrome (a pregnancy complication involving liver problems and low platelets). After delivery, her low platelet count and signs of red blood cell breakdown continued, which led clinicians to check ADAMTS13 activity and an inhibitor, confirming immune TTP based on severe deficiency with inhibitor positivity. [11]

For patients and caregivers, this report is mainly background information about why diagnosis can be challenging around delivery and why additional blood testing may be used when the clinical picture does not fit a single pregnancy complication. Because it is one patient, it cannot show how often this happens or which signs are most reliable, and it does not replace individualized medical assessment. [11]

Across these reports, different conditions produced a similar pattern of low platelets and red blood cell breakdown that can resemble thrombotic thrombocytopenic purpura (TTP). The main message is that TTP-like illness can come from very different causes (nutrition-related, infection-related, or complement-related), and tests such as ADAMTS13 activity did not look the same in every mimic. [12] [13] [14]

In one adult patient, severe vitamin B12 deficiency from pernicious anemia caused pancytopenia (low counts across blood cell types) and strong signs of hemolysis that resembled a thrombotic microangiopathy, but ADAMTS13 activity was not in the range typically expected for TTP. After vitamin B12 and folate replacement plus supportive care, blood counts and neurologic symptoms improved gradually, and plasma exchange was avoided. [12]

In one adult with severe Plasmodium falciparum malaria, the patient developed microangiopathic features and very low ADAMTS13 activity (7.6%), creating a close look-alike to TTP. With artesunate plus intensive supportive care that included plasma exchange and continuous kidney support, the patient improved and ADAMTS13 activity later rose to 42%. [13]

In one child with hemolytic uremic syndrome and severe brain involvement, ADAMTS13 activity was 13%, above the below-10% level that points to TTP, so the authors ruled TTP out; complement-related findings were present (including low C3 and genetic deletions), showing another pathway that can overlap with TTP-like lab results. After eculizumab and supportive care, blood and kidney measures improved quickly while neurologic recovery took much longer, continuing over years with mild residual deficits despite eventual normal kidney function. [14]

For patients and caregivers, these reports are mainly background information that helps explain why doctors sometimes discuss conditions that can look like TTP early on, especially when there are signs of infection, nutritional deficiency, kidney failure, or neurologic symptoms. They also show that a single lab value, including ADAMTS13 activity, may not fully explain what is happening in every TTP-like illness. Because all three papers describe single patients, it remains uncertain how often these exact patterns occur or how well they predict outcomes in broader groups.

Across the studies, long-term follow-up showed that clotting-related blood disorders can have a relapsing course and may lead to lasting organ problems, but outcomes vary widely depending on the underlying cause. In inherited thrombotic thrombocytopenic purpura (TTP), fewer acute episodes were reported during periods of regular plasma-based prevention, yet many people still had ongoing symptoms and needed repeated care. [15] [16]

In a multinational retrospective cohort of 78 people with inherited TTP caused by very low ADAMTS13 activity, acute TTP episodes were common over time, with 92 acute episodes reported in 55 people. Most episodes happened when people were not on plasma-based prevention, and some of those episodes led to organ damage, while episodes during prevention did not. [15]

When the same inherited TTP study looked more closely at patients who met clinical trial-style criteria and were on regular prevention, the rate of acute episodes was lower, but episodes still happened in a small number of people. The study also reported that many people stopped or interrupted plasma-based prevention at times due to side effects or feeling it was not helping enough, highlighting real-world limits of long-term infusion-based care. [15]

A separate 9-year study of 303 children with a first episode of thrombotic microangiopathy (a group of conditions that includes TTP-like illnesses) found that long-term outcomes depended strongly on the cause. Secondary forms were most common and had higher risk of death or kidney failure, especially when children had heart failure or shock at the start or needed mechanical ventilation. [16]

For families living with inherited TTP, this month’s research mainly adds background about what the disease can look like over many years: repeated acute episodes can occur, and organ damage is a real concern, but fewer acute episodes were reported during periods of regular plasma-based prevention in one real-world cohort. These studies do not settle how to best prevent long-term complications for every person, because they were retrospective and included different patient groups, and they also show that long-term care can be interrupted by side effects or limited perceived benefit. [15] [16]

Across this month's evidence for brain complications in thrombotic thrombocytopenic purpura (TTP), the main message comes from one detailed case report: TTP can present with a severe ischemic stroke involving large brain arteries, and clotting can recur quickly even after a clot is removed. The report also highlights that TTP may occur alongside other clotting-related conditions affecting the heart, which can complicate the stroke picture. [17]

In this case, a 29-year-old woman with autoimmune rheumatologic disease had an acute ischemic stroke due to multiple large vessel blockages, and testing showed very low ADAMTS13 (a blood protein that helps prevent small-vessel clotting in TTP). During mechanical thrombectomy, there was extensive recurrent clot formation and repeated new blockages inside the brain. [17]

The same patient was later found to have nonbacterial thrombotic endocarditis (a form of sterile clotting on heart valves), which can also contribute to clots traveling to the brain. She was treated with plasma exchange, high-dose corticosteroids, and rituximab, and the authors reported a good response with no recurrent ischemic events during follow-up. [17]

For patients and caregivers, this report mainly serves as background information showing one way TTP-related brain problems can look in real life: sudden stroke from large artery blockages, possible repeated clotting during emergency stroke care, and the possibility of overlapping causes such as heart valve clotting. Because it is a single-patient report, it cannot show how often this happens or predict outcomes for others, and it does not establish which approaches work best across different people with TTP.