Ischemic colitis as a manifestation of thrombotic microangiopathy following bone marrow transplantation

HELLP syndrome complicated by ischemic colitis: A case report

Key Clinical Message

HELLP syndrome is a complicated disorder associated with many unknown complications, which ischemic colitis might be one of. Timely diagnosis and prompt management with multidisciplinary approach is the key for a favorable outcome.

Abstract

HELLP syndrome is a triad of hemolysis (H), elevated liver enzymes (EL), and low platelet count (LP) which is considered a rare but serious pregnancy complication. HELLP syndrome is mainly associated with pre-eclampsia, but can also occur individually. It may cause maternal and fetal mortality and some life-threatening morbidity. The best management considered for HELLP syndrome is immediate delivery in most cases. We report a 32-week pregnant woman with pre-eclampsia who developed HELLP syndrome shortly after admission which led to a preterm cesarean section. Rectal bleeding and diarrhea started the day after delivery, and all the workups and imaging suggested ischemic colitis. She received intensive care and supportive management. The patient recovered and was discharged uneventfully. HELLP syndrome may be associated with many unknown complications, and ischemic colitis might be one of them. Timely diagnosis and prompt management with a multidisciplinary approach is the key to a favorable outcome.

Cerebral vascular injury in transplant-associated thrombotic microangiopathy

Transplant-associated thrombotic microangiopathy (TA-TMA) and atypical hemolytic uremic syndrome (aHUS) are complement-mediated TMAs. The central nervous system (CNS) is the most common extrarenal organ affected by aHUS, and, despite mechanistic overlap between aHUS and TA-TMA, CNS involvement is rarely reported in TA-TMA, suggesting that CNS involvement in TA-TMA may be underdiagnosed and that these patients may benefit from complement blockers. In addition, there are no widely used histologic or radiologic criteria for the diagnosis of TMA in the brain. Thirteen recipients of pediatric hematopoietic cell transplants (HCTs) who had TA-TMA and who underwent autopsy were studied. Seven of 13 brains had vascular injury, and 2 had severe vascular injury. Neurologic symptoms correlated with severe vascular injury. Classic TMA histology was present and most often observed in the cerebellum, brainstem, and cerebral white matter. Abnormalities in similar anatomic regions were seen on imaging. Brain imaging findings related to TMA included hemorrhages, siderosis, and posterior reversible encephalopathy syndrome. We then studied 100 consecutive HCT recipients to identify differences in neurologic complications between patients with and those without TA-TMA. Patients with TA-TMA were significantly more likely to have a clinical concern for seizure, have an electroencephalogram performed, and develop altered mental status. In summary, our study confirms that TA-TMA involves the brains of recipients of HCT and is associated with an increased incidence of neurologic symptoms. Based on these findings, we propose that patients with low- or moderate-risk TA-TMA who develop neurologic complications should be considered for TA-TMA-directed therapy.

Pathology of Gastrointestinal and Liver Complications of Hematopoietic Stem Cell Transplantation

CONTEXT.—

Despite advances in therapeutic and preventive measures, hematopoietic stem cell transplant recipients remain at risk for a variety of gastrointestinal and liver complications.

OBJECTIVE.—

To detail the pathologic features of the various gastrointestinal and liver complications occurring after hematopoietic stem cell transplantation in relation to their clinical context. The specific complications covered include graft-versus-host disease, mycophenolate mofetil-induced injury, timeline of infections, neutropenic enterocolitis, gastrointestinal thrombotic microangiopathy, sinusoidal obstruction syndrome, hepatic iron overload, and the controversy around cord colitis syndrome.

DATA SOURCES.—

The content of this article is based on pertinent peer-reviewed articles in PubMed, relevant textbooks, and on the authors' personal experiences.

CONCLUSIONS.—

The final histopathologic diagnosis requires the integration of clinical and histologic findings and the exclusion of other competing causes of injury. Review of the clinical data, including the original disease pretransplant, the type of transplant, the timing of the gastrointestinal and/or liver manifestations, the timing of the biopsy after transplant, the presence of graft-versus-host disease in other organs and sites, the list of drug regimens, and the clinical and laboratory evidence of infection, is the key to reaching the proper histologic diagnosis.

A Complete Histologic Approach to Gastrointestinal Biopsy From Hematopoietic Stem Cell Transplant Patients With Evidence of Transplant-Associated Gastrointestinal Thrombotic Microangiopathy

CONTEXT

- Transplant-associated thrombotic microangiopathy is a serious complication of hematopoietic stem cell transplant that may progress to multi-organ dysfunction. Transplant-associated thrombotic microangiopathy may involve the intestinal vasculature (intestinal transplant-associated thrombotic microangiopathy [iTMA]), causing patients to experience debilitating symptoms of ischemic colitis, including disproportionately severe abdominal pain and gastrointestinal bleeding, requiring heavy narcotic use and frequent transfusion support. Pathophysiology remains poorly investigated but may include endothelial damage mediated by inflammatory markers and the complement system. Endoscopy of hematopoietic stem cell transplant patients often produces biopsy samples, in which mucosal lamina propria capillaries are sufficient for an evaluation of iTMA features.

OBJECTIVE

- To provide a detailed review of histologic features of iTMA.

DATA SOURCES

- We conducted a systematic review of studies assessing histologic features of iTMA. Studies were identified by PubMed search and included a cohort study performed by our group.

CONCLUSIONS

- The histologic hallmark of iTMA is endothelial cell injury that leads to hemorrhage and thrombosis of the capillaries. Histologic features include endothelial cell swelling, endothelial cell separation, perivascular mucosal hemorrhage, intraluminal schistocytes, intraluminal fibrin, intraluminal microthrombi, loss of glands, and total denudation of mucosa. Identification of features consistent with iTMA has immediate implications for clinical management that could potentially improve outcome and survival.

Histologic Features of Intestinal Thrombotic Microangiopathy in Pediatric and Young Adult Patients after Hematopoietic Stem Cell Transplantation

High-risk transplantation-associated thrombotic microangiopathy (TMA) can present with multisystem involvement and is associated with a poor outcome after hematopoietic stem cell transplantation (HSCT), with < 20% 1-year survival. TMA may involve the intestinal vasculature and can present with bleeding and ischemic colitis. There are no established pathologic criteria for the diagnosis of intestinal TMA (iTMA). The goal of our study was to identify histologic features of iTMA and describe associated clinical features. We evaluated endoscopic samples from 50 consecutive HSCT patients for 8 histopathologic signs of iTMA and compared findings in 3 clinical groups based on the presence or absence of systemic high-risk TMA (hrTMA) and the presence or absence of clinically staged intestinal graft-versus-host disease (iGVHD): TMA/iGVHD, no TMA/iGVHD, and no TMA/no iGVHD. Thirty percent of the study subjects had a clinical diagnosis of systemic hrTMA. On histology, loss of glands, intraluminal schistocytes, intraluminal fibrin, intraluminal microthrombi, endothelial cell separation, and total denudation of mucosa were significantly more common in the hrTMA group (P < .05). Intravascular thrombi were seen exclusively in patients with hrTMA. Mucosal hemorrhages and endothelial cell swelling were more common in hrTMA patients but this difference did not reach statistical significance. Patients with hrTMA were more likely to experience significant abdominal pain and gastrointestinal bleeding requiring multiple blood transfusions (P < .05). Our study shows that HSCT patients with systemic hrTMA can have significant bowel vascular injury that can be identified using defined histologic criteria. Recognition of these histologic signs in post-transplantation patients with significant gastrointestinal symptoms may guide clinical decisions.

Atypical Hemolytic Uremic Syndrome and Chronic Ulcerative Colitis Treated with Eculizumab

Background

Hemolytic-uremic syndrome (HUS) presents with hemolytic anemia, thrombocytopenia, and thrombotic microangiopathy of the kidney and usually results from Shiga-toxin induced activation of the alternative complement pathway. Gastroenteritis is a common feature of the Shiga-toxin producing Escherichia coli HUS, referred to as STEC-HUS. An inherited or acquired complement dysregulation may lead to HUS referred to as non-STEC or atypical (a)HUS. Although gastroenteritis is not a common presentation of aHUS, some patients develop ischemic colitis and may be misdiagnosed as acute appendicitis or acute ulcerative colitis (UC).

Case Diagnosis –Treatment

We present a patient with low circulating complement (C) 3 levels who developed aHUS in the course of chronic active UC. Resolution of renal and gastrointestinal manifestations in response to treatment with eculizumab, a humanized monoclonal antibody against terminal C5 protein suggests the role of alternative complement in the pathogenesis of both, aHUS and UC.

Conclusion

This case illustrates that dysregulation of the alternative complement pathway may manifest in other organs besides the kidney and that the circulating C3 levels do not correlate with the disease activity or the clinical response to eculizumab.

Extra-renal manifestations of complement-mediated thrombotic microangiopathies

Thrombotic microangiopathies (TMA) are rare but severe disorders, characterized by endothelial cell activation and thrombus formation leading to hemolytic anemia, thrombocytopenia, and organ failure. Complement over activation in combination with defects in its regulation is described in an increasing number of TMA and if primary for the disease denominated as atypical hemolytic-uremic syndrome. Although TMA predominantly affects the renal microvasculature, extra-renal manifestations are observed in 20% of patients including involvement of the central nerve system, cardiovascular system, lungs, skin, skeletal muscle, and gastrointestinal tract. Prompt diagnosis and treatment initiation are therefore crucial for the prognosis of disease acute phase and the long-term outcome. This review summarizes the available evidence on extra-renal TMA manifestations and discusses the role of acute and chronic complement activation by highlighting its complex interaction with inflammation, coagulation, and endothelial homeostasis.

A rare case of colic thrombotic microangiopathy in renal transplantation

INTRODUCTION

We report a case of thrombotic microangiopathy (TM) in patient with UC and kidney transplantation.

CASE REPORT

A 59-year-old Caucasian may with a renal transplant, with atrial fibrillation and ulcerative colitis (UC), was referred for asthenia, fever (38 degrees C), anemia, colicky pain, and bloody diarrhea. The maintenance therapy consisted of CSA, sodium mycophenolate, steroids, ticlopidine, and mesalazine. Laboratory data, colonscopy, and colic mucosal biopsy revealed de novo colic TM. We administered antibiotics and antishock therapy, reducing CSA, withdrawing ticlopedine and maintaining mesalazine with the resolution of the problem.

CONCLUSION

Posttransplantation TM is an uncommon but severe complication of kidney transplantation associated with reduced graft survival and a high risk for death. Only an early, accurate diagnosis with optimal treatment permits resolution of the problem.

Usefulness of Sequential Automated Analysis of Fragmented Red Blood Cells for the Differential Diagnosis of Thrombotic Thrombocytopenic Purpura-Hemolytic Uremic Syndrome following Allogeneic Hematopoietic Cell Transplantation

Differentiating thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) from other complications following allogeneic hematopoietic cell transplantation (HPCT) requires objective, reliable markers. To this purpose, we assessed the clinical usefulness of sequential quantified analysis of fragmented red blood cells (FRC) with the Sysmex XE-2100 automated hematology analyzer. The correlation between manual and automated counting was significant (r = 0.917; P < .0001). Of 25 cases, the peak FRC percentage (FRC%) exceeded 1.3% after allogeneic HPCT in 11 cases, and lactate dehydrogenase levels were elevated in 5 of these 11 cases. Two patients received diagnoses of TTP-HUS following allogeneic HPCT, and both had initial diagnoses of acute graft-versus-host disease. In both cases, the sharp increase in the FRC% to >3% simultaneously with clinical exacerbation was helpful for differentiating TTP-HUS following allogeneic HPCT from other complications. We conclude that FRC% data sequentially obtained by an automated count seem to be useful as an objective marker of TTP-HUS following allogeneic HPCT.