January 2026 Research Update

Across this small, early-phase clinical experience, CD19 CAR T-cell therapy was linked to deep responses in people whose autoimmune hemolytic anemia had not responded to multiple prior treatments. Safety issues were generally described as manageable, but immune-related reactions and infections still occurred, and follow-up was about a year, so long-term durability remains uncertain. [1]

All 11 patients reached a complete response after one infusion, with the median time to complete response reported as 45 days. The median duration of being in remission without ongoing AIHA drugs was 11.5 months in the reported follow-up period. [1]

Side effects included cytokine release syndrome (an inflammatory reaction) at grade 1 to 2 in 9 patients and mild nervous system symptoms (ICANS) at grade 1 in 1 patient. Infections were reported 15 times across 7 patients, with no grade 4 or 5 infections reported, and one patient had grade 3 immune effector cell-associated hematotoxicity (low blood counts related to treatment). [1]

Detailed immune profiling suggested that, in people who stayed off AIHA medicines, the returning B cells were mostly naive B cells (immature B cells that have not learned to make a specific antibody yet). The study also described a possible relapse pattern involving a specific B-cell group (HLA-DRB5+), CD4+ T cells, and long-lived plasma cells, which may help explain why AIHA can return in some people. [1]

For patients and caregivers, this report adds early evidence that a one-time immune cell therapy approach may sometimes produce drug-free remissions in very hard-to-treat autoimmune hemolytic anemia, but it is based on only 11 people and limited follow-up. The main near-term takeaway is that the therapy required close monitoring for immune reactions and infections, and the long-term balance of benefit and risk is still being defined. The immune profiling results are mainly background research for now, aimed at understanding who stays in remission and why relapse can happen.

Across these papers, autoimmune hemolytic anemia (AIHA) was described as a rare but potentially severe reaction that can be triggered by certain medicines, including antibiotics and immune-based cancer drugs. The reports also showed that lab tests can be complicated: some people may have negative or unclear antibody test results even when AIHA is suspected. Overall, the evidence here is based on case reports and a summary of published cases, so it describes patterns seen in reported patients rather than proving how often this happens. [2] [3] [4]

In one child, two cephalosporin antibiotics (cefuroxime and ceftriaxone) were linked to severe drug-induced immune hemolytic anemia, with hemoglobin falling to 2.6 g/dL and signs of shock and temporary kidney problems. Specialized testing supported that both drugs were involved, and her hemoglobin rose quickly after the cephalosporins were stopped and different antibiotics were used. As a single-patient report, it cannot show how common this reaction is, but it illustrates how dramatic drug-triggered hemolysis can be. [2]

A systematic review collected 29 published cases of pembrolizumab-related AIHA (an immune checkpoint inhibitor used for cancer), with a median time of 30 days from the first dose to AIHA and a median of 2.5 treatment cycles. Reported symptoms included fatigue, shortness of breath, and dizziness, and 17.2% were described as having a negative direct antiglobulin test (DAT), meaning the common antibody test was not always positive in these reports. In this set of published cases, 96.5% were reported to respond after pembrolizumab was stopped and patients received glucocorticoids and red blood cell transfusion. [3]

Another single-patient report described a woman treated with nivolumab (another immune checkpoint inhibitor) who developed multiple immune-related problems during a prolonged hospitalization, including encephalitis and, later, problems the authors described as possible immune-related side effects: AIHA and thyroid and pituitary inflammation. The report noted that confirming AIHA was difficult because the DAT was inconclusive while she was on steroids, and her course was complicated by serious hospital-acquired infections, with death from sepsis. This case highlights that immune-related side effects can involve more than one organ system and may occur alongside other severe complications. [4]

For patients and caregivers, this set of papers mainly serves as background about an uncommon cause of AIHA: certain medicines, including some antibiotics and immune-based cancer therapies, have been reported to trigger hemolysis in some people. The reports also suggest that standard blood tests used to support an AIHA diagnosis (like the DAT) may be negative or hard to interpret in some medicine-related cases, especially in complex hospital settings. What remains uncertain from these papers is how often these reactions happen, who is most at risk, and how results differ across different cancers, drug combinations, or prior health conditions.

Taken together, these papers suggest that autoimmune hemolytic anemia (AIHA) and related autoimmune blood cell conditions can sometimes be part of a broader immune system condition present from birth, and that blood-based immune markers and genetic testing can help uncover that possibility. At the same time, real-world evaluation practices differ a lot between clinicians, and single-patient reports show possible gene links that still need confirmation in larger groups. [5] [6] [7] [8]

In a prospective study of 104 people with autoimmune cytopenia (autoimmune low blood counts), about half had an inborn error of immunity, including many with single-gene causes, and the proportion was higher in people with AIHA and Evans syndrome. People with an inborn error of immunity more often had low antibody levels in the blood and a pattern of immune cell differences, along with higher levels of immune signaling proteins measured in blood. [5]

A survey of 47 North American clinicians caring for pediatric Evans syndrome reported no consensus on which diagnostic tests to use, even though many clinicians said they used a consistent approach within their own practice. Testing for autoimmune conditions was commonly included, while testing aimed at inborn errors of immunity varied; most respondents used commercial genetic testing and often ran into insurance barriers. [6]

Two case reports in children highlight how AIHA can occur alongside immune or genetic factors, but these single cases cannot show how often this happens. One report described a 4-year-old girl with very low immunoglobulin A (selective IgA deficiency) who had repeated AIHA episodes and many infections, raising concern in that report about possible progression to a broader antibody deficiency over time. [8]

Another report described a 6-year-old boy with AIHA who carried a specific IFIH1 gene variant; lab testing in that paper suggested the variant disrupted normal gene splicing and reduced MDA5 activity, which the authors proposed could contribute to AIHA in that patient. The child responded well to corticosteroids and remained in remission on low-dose treatment in the report, but this does not establish the same gene as a cause of AIHA for others. [7]

For patients and caregivers, this set of studies is mainly about understanding why AIHA happens in some people, especially when AIHA occurs with other autoimmune blood count problems (like Evans syndrome) or repeated infections. The strongest evidence here comes from a single region cohort showing that underlying immune system conditions and measurable immune markers were common in autoimmune cytopenia, while the survey shows that the medical community does not yet have a standardized testing approach. The case reports add background context that certain immune deficiencies or rare gene changes may be involved for some children, but it remains uncertain how often those specific causes apply in the broader AIHA population. [5] [6] [7] [8]

Across these early, small studies (a 4-person case series and two single-patient reports), autoimmune hemolytic anemia (AIHA) appeared in the setting of other medical conditions, and the blood problems sometimes involved more than red blood cells. Overall, the pattern was that treating or addressing the underlying condition and/or using immune-suppressing medicines was linked to improvement, but relapses and uneven recovery across blood cell types were also described. [9] [10] [11]

In a retrospective case series of four adults with thymoma (a tumor of the thymus gland), all developed immune-related low blood counts affecting at least two blood cell lineages, not only red blood cells. Relapses were frequent (three of four), and recovery of neutrophils and platelets tended to happen faster (within 1 to 2 months) than recovery of red blood cells. [9]

The same thymoma series reported immune and genetic clues that may point to T-cell driven immune disruption in some patients, including clonal T-cell receptor rearrangements consistent with T-cell large granular lymphocytic leukemia in two patients. The authors also noted significant infections (such as pneumonia) during diagnosis or treatment, highlighting the real-world complexity in these combined conditions. [9]

One case report described a 47-year-old woman with alcoholic liver cirrhosis who had AIHA plus low platelets and was later diagnosed with early disseminated Lyme disease; she also had nerve symptoms (nocturnal neuropathic pain and foot drop). After antibiotic treatment (ceftriaxone and doxycycline) along with prednisone for AIHA, her blood counts and symptoms improved over time. [10]

Another case report described a child with AIHA that did not respond to steroids and was found to have unicentric Castleman disease (a localized lymph node overgrowth). After surgical removal of the Castleman lesion, the anemia reversed, suggesting the localized disease was a sufficient cause in this one patient. [11]

For patients and caregivers, these reports add context that AIHA can sometimes occur alongside other conditions such as thymoma, infections like Lyme disease, or rare immune-related growths such as unicentric Castleman disease, and the blood issues may include low platelets or low neutrophils in addition to anemia. The evidence here is limited (very small numbers and individual cases), so it mainly serves as background on possible links rather than a guide to what will happen in most people. What remains uncertain is how often these connections occur, which biological pathways matter most, and which approaches work best across different underlying conditions.

Across two single-patient reports, autoimmune hemolytic anemia after delivery was linked to uncommon but life-threatening complications that involved bleeding, abnormal clotting, and in one case kidney injury and spleen bleeding. [12] [13] Both reports describe complex hospital courses where multiple supportive steps were needed, and both patients later stabilized, but these stories cannot predict what will happen for most people.

One woman developed disseminated intravascular coagulation (a severe clotting disorder) after postpartum hemorrhage, alongside warm autoimmune hemolytic anemia (a form where antibodies attack red blood cells at body temperature). [12] After emergency bleeding control, steroids, and transfusions using washed red blood cells, her clotting tests and hemolysis markers returned to normal, and there was no evidence of ongoing hemolysis at 2 months.

Another postpartum patient developed Evans syndrome (autoimmune hemolytic anemia plus immune thrombocytopenia, meaning low platelets) complicated by atypical hemolytic uremic syndrome tied to cytomegalovirus (CMV), with kidney injury requiring dialysis and a splenic rupture causing hemorrhagic shock. [13] Her testing suggested problems in the complement immune pathway (including low C3 and factor H changes), and she had partial responses to several immune treatments before stabilizing on ongoing therapy including mycophenolate and the complement blocker eculizumab, tolerated for about 9 months.

For patients and caregivers, these reports mainly serve as background about the range of complications that have been described around childbirth when autoimmune hemolytic anemia is present, including bleeding and clotting problems, low platelets, kidney injury, and spleen bleeding. [12] [13] Because each paper describes only one person with multiple overlapping conditions, it remains uncertain how often these complications happen, which risk factors matter most, and how closely any single patient will match these experiences.

Two papers focused on safety issues that can come up alongside autoimmune hemolytic anemia (AIHA): blood clots and transfusion-related worsening of hemolysis. Overall, the reports point to higher clot risk during active hemolysis or relapse, and they show that uncommon antibody patterns can sometimes make transfusion more complicated. [14] [15]

In a single-center retrospective study of 92 adults with AIHA, 20 people had at least one clot (20 patients had 29 total clotting events), including events at the time AIHA was diagnosed and later events during follow-up. Most later vein clots happened during AIHA relapses rather than during remission, suggesting risk may rise when hemolysis is active. [14]

The same study found that inherited clotting disorders were uncommon and did not clearly explain who developed clots, while antiphospholipid antibodies (an acquired clotting risk) were present in 10 of 92 people. The authors concluded routine screening for inherited thrombophilia was not supported, but that testing for antiphospholipid antibodies may be useful when evaluating clot risk in AIHA. [14]

A separate case report described one person with warm AIHA whose hemolysis worsened after receiving red blood cells that carried the e antigen, matching an unusual autoantibody pattern (anti-e specificity). The paper also reviewed 18 earlier case reports and noted that post-transfusion worsening was not reported in most of those cases, showing this appears uncommon but possible. [15]

For patients and caregivers, these papers mainly add context for why clinicians may pay closer attention to clotting risk during active hemolysis and why transfusion planning in AIHA often includes detailed blood-bank testing beyond a basic blood type. What remains uncertain is how well clot risk can be predicted for an individual person, and how often rare antibody patterns like anti-e meaningfully change transfusion outcomes, since much of the transfusion evidence comes from case reports. [14] [15]

Across these studies, C3-only direct antiglobulin test (DAT) autoimmune hemolytic anemia (AIHA) in children most often appeared after infections and often settled with supportive care, but immune-related complications can matter in specific settings such as after stem cell transplant. Overall, the evidence is based on retrospective cohorts, so it can show patterns but cannot prove what treatment works best. [16] [17]

In a nationwide French registry of 142 children with C3d-only DAT AIHA, 63% occurred after an infection and cases clustered in winter, with many children needing transfusions during the acute phase. Steroids were used in 82%, but children who received steroids had lower hemoglobin at presentation and had longer hospitalizations and more transfusions, suggesting steroids did not clearly improve the typical course in this group. Relapse was reported in about 5% by 2 years, and a smaller subset had other immune system conditions or immune dysregulation features. [16]

A separate single-center study looked at autoimmune cytopenias (low blood counts caused by the immune system) after pediatric allogeneic stem cell transplant, where AIHA was one of several forms and occurred as part of a broader post-transplant problem. Autoimmune cytopenia developed in 8.5% of transplanted children, and chronic graft-versus-host disease was an independent risk factor; first treatments (steroids and/or IVIG) led to complete remission in 48.6%, with additional remissions seen after other immune-targeting medicines, but deaths still occurred in this high-risk transplant population. [17]

For many families, these results mainly provide context about what clinicians often see: C3-only DAT AIHA in otherwise typical childhood presentations is often triggered by infection and may resolve with supportive care, with relatively few relapses reported in the registry. At the same time, the transplant study shows that AIHA can look different when it occurs alongside other transplant-related immune complications, where outcomes and risks may be driven by the overall transplant situation rather than AIHA alone. What remains uncertain is which specific subgroups benefit most from particular immune-targeting treatments, because both studies were retrospective and care varied between patients and centers. [16] [17]