Sickle cell disease: a clinical and histopathologic study of the liver in living children

The Liver in Sickle Cell Disease

Liver involvement is found in nearly 40% of children with sickle cell disease. The most frequent complication is cholelithiasis. The most severe complication is acute hepatic crisis, with symptoms ranging from increasing jaundice to multiple organ failure and death. The emergency and mostly efficient treatment is exchange transfusion. Chronic cholangiopathy is increasingly recognized, with autoimmune features in most cases, worsened by chronic ischemia. Transfusion-related iron overload is not yet a concern in children, and hepatotoxicity of iron chelators is rare. We propose recommendations to prevent, explore, and treat these complications. We emphasize the close collaboration required between hepatologists and specialists of sickle cell disease.

Autoimmune Liver Disease in Children with Sickle Cell Disease

OBJECTIVE

To assess the incidence, clinical features, and outcome of autoimmune liver disease (AILD) in patients with sickle cell disease (SCD).

STUDY DESIGN

Single center retrospective review of patients with SCD with AILD referred between 1999 and 2015.

RESULTS

Thirteen of 77 (17%) patients with SCD with hepatic dysfunction were diagnosed with AILD (median age 11, range, 3.4-16 years) with a female preponderance (77%). Acute hepatitis and insidious onset were the commonest presentations. Two patients (15%) presented with acute liver failure. In 2 patients (15%), parvovirus B19-induced transient red cell aplasia preceded the diagnosis of AILD. All patients were positive for antinuclear and/or smooth muscle autoantibodies. Six of 12 patients (50%) had cholangiopathy on cholangiogram suggesting autoimmune sclerosing cholangitis (ASC). Liver biopsy, performed in 11 patients without complications, showed interface hepatitis in 90%. Patients with AILD were treated with standard immunosuppression. After a median follow-up of 3.8 years (range, 0.2-14.3), 10 patients are alive (1 was transplanted 6.4 years after diagnosis); 2 are lost to follow-up; 1 died of subdural hemorrhage before starting treatment for AILD. Five (42%) achieved full and 4 (33%) partial biochemical remission. Ulcerative colitis, present in 4 patients (2 male patients, 3 with ASC) was diagnosed in 2 patients before and in 2 patients after the diagnosis of AILD.

CONCLUSIONS

AILD is not uncommon in patients with SCD, affecting mainly female patients and responding satisfactorily to immunosuppressive treatment. Liver biopsy is helpful in confirming the diagnosis and can be safely performed in the absence of acute vaso-occlusive sickling episodes. Ulcerative colitis is common in the presence of ASC.

Beyond the definitions of the phenotypic complications of sickle cell disease: an update on management

The sickle hemoglobin is an abnormal hemoglobin due to point mutation (GAG → GTG) in exon 1 of the β globin gene resulting in the substitution of glutamic acid by valine at position 6 of the β globin polypeptide chain. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of sickle cell disease in general and sickle cell anemia in particular. The disease itself is chronic in nature but many of its complications are acute such as the recurrent acute painful crises (its hallmark), acute chest syndrome, and priapism. These complications vary considerably among patients, in the same patient with time, among countries and with age and sex. To date, there is no well-established consensus among providers on the management of the complications of sickle cell disease due in part to lack of evidence and in part to differences in the experience of providers. It is the aim of this paper to review available current approaches to manage the major complications of sickle cell disease. We hope that this will establish another preliminary forum among providers that may eventually lead the way to better outcomes.

Hypoxic hepatitis: a challenging diagnosis

Hypoxic hepatitis (HH), one of the most common causes of acute liver injury, has a prevalence of up to 10% of admissions in intensive care units across the world. Inadequate oxygen uptake by the hepatocytes resulting in centrilobular necrosis associated with abnormally raised levels of the serum transaminases (ALT, AST) in patients with clinical history of cardiac, respiratory, or circulatory failures is the key feature of this condition. Abstracts, reviews, case reports, and research letters from various sources such as Pubmed, Proquest, Ovid, Google Scholar, and ISI Web of Knowledge dating from 1970 to 2011 were read and analyzed thoroughly. A study of 100 patients with HH, carried out from 2009 to 2010 at Tongji Hospital of Tongji University, Shanghai, People's Republic of China, is also documented. The contributing factors leading to HH are passive congestion, ischemia, and arterial hypoxemia of the liver. Ischemia/reperfusion injury also has a major role in HH. Some of its complications are spontaneous hypoglycemia, a high level of serum ammonia, and respiratory insufficiency due to hepatopulmonary syndrome. The therapy of HH lies mainly in the treatment of the main underlying causes, and this leads to the successful reversion of HH. The aim of this review is to present a simplified concept about the etiology, pathophysiology, mechanism, clinical manifestations, diagnosis, and treatment of HH.

Iron in sickle-cell disease: what have we learned over the years?

Over the last four decades, monumental advances have been made in the understanding, assessment, and management of transfusion-dependent patients, which have translated into significant improvements in patient morbidity and mortality. Important lessons have been learned from extensive clinical experience of iron management in the thalassemias, but greater knowledge of key differences in the sickle-cell disease (SCD) population may impact on our approach to patient assessment and management. The unique pathophysiology of SCD is reflected in a distinct pattern of iron loading with minimal organ-specific injury. An appreciation and understanding of these differences should allow us to develop tailored management approaches that optimize patient outcomes.

Infections in thalassemia and hemoglobinopathies: focus on therapy-related complications

The clinical approach to thalassemia and hemoglobinopathies, specifically Sickle Cell Disease (SCD), based on transfusions, iron chelation and bone marrow transplantation has ameliorated their prognosis. Nevertheless, infections still may cause serious complications in these patients. The susceptibility to infections in thalassemia and SCD arises both from a large spectrum of immunological abnormalities and from exposure to specific infectious agents. Four fundamental issues will be focused upon as central causes of immune dysfunction: the diseases themselves; iron overload, transfusion therapy and the role of the spleen. Thalassemia and SCD differ in their pathogenesis and clinical course. It will be outlined how these differences affect immune dysfunction, the risk of infections and the types of most frequent infections in each disease. Moreover, since transfusions are a fundamental tool for treating these patients, their safety is paramount in reducing the risks of infections. In recent years, careful surveillance worldwide and improvements in laboratory tests reduced greatly transfusion transmitted infections, but the problem is not completely resolved. Finally, selected topics will be discussed regarding Parvovirus B19 and transfusion transmitted infections as well as the prevention of infectious risk postsplenectomy or in presence of functional asplenia.

Hepatic iron overload in children with sickle cell anemia on chronic transfusion therapy

Hepatic iron overload is a serious complication of chronic transfusion therapy in patients with sickle cell disease (SCD). No firm consensus has been reached with regard to correlation between hepatic iron content (HIC) and variables including age, number of transfusions, and serum iron makers. Also, the role of HIC in determining hepatic injury is not well established. There is scarcity of data on chronically transfused children with SCD and no other confounding liver pathology. We aimed to further explore relationships between these variables in a cohort of children with SCD on chronic transfusion therapy naive to chelation. Liver biopsies obtained before starting chelation therapy from 27 children with sickle cell anemia receiving chronic transfusion therapy were evaluated for histologic scoring and determination of HIC. Average serum ferritin and iron saturation values were determined for 6 months before biopsy. Duration and total volume of transfusion were obtained from the medical records. All children were negative for human immunodeficiency virus, hepatitis B virus, and hepatitis C virus infections. Mean age at biopsy was 10.95+/-3.34 years. Mean duration and total volume of transfusions were 50.0+/-26.6 months and 17.4+/-9.6 L, respectively. Pearson product-moment bivariate correlation coefficients indicated significant correlations between HIC and histologic iron score, serum ferritin, iron saturation, age, and transfusion volume. After adjusting for transfusion volume, a significant correlation was only seen between HIC and transfusion volume. Mean HIC was 21.8+/-10.4 mg/g dry weight, with fibrosis observed in 10 patients and lobular inflammation in 9. HIC was higher in biopsies with fibrosis (28.2+/-3.8 mg/g) than biopsies without fibrosis (17.6+/-18.3 mg/g; P=0.012). HIC did not differ between biopsies with lobular inflammation (25.5+/-4.0 mg/g) and biopsies without inflammation (19.9+/-2.5 mg/g; P=0.22). These findings show that transfusion volume provides more insight on hepatic iron overload than serum iron markers.

Liver involvement in acute vaso-occlusive crisis of sickle cell disease: prevalence and predisposing factors

OBJECTIVE

To study the prevalence and predisposing factors of liver involvement in sickle cell disease (SCD) of patients with acute vaso-occlusive crisis.

MATERIAL AND METHODS

We prospectively evaluated 41 consecutive patients (44% M, median age 39 years, range 16-56 years) with homozygous (HbSS; 12 cases) or sickle cell-beta thalassemia (HbSbeta-thal; 29 cases), admitted to our Medical Department in the period 2002 to 2004. Severity of crisis was graded by in-house-modified APACHE score; presence of asplenia or functional hyposplenism was also considered. Hematological and biochemical parameters including various relevant enzymes/isoenzymes were followed daily.

RESULTS

Despite the fact that only 9 patients (22%) presented with acute painful hepatomegaly, liver involvement was evident in 16 (39%); hepatocellular-type injury was found in 1 patient, cholestatic in 8, and mixed in 7. Severity of crisis was not related to liver involvement (score 20.6 versus 18.2), but liver involvement occurred in the presence of normal spleen function (p<0.001) and platelet counts <500,000/mm(3) (p<0.001) were. Patients with liver involvement, compared with those without, had higher total and direct bilirubin levels (4.3 versus 2.9 mg/dL, p=0.050; 1.9 versus 0.8 mg/dL, p=0.010, respectively), lower hematocrit (19% versus 23%, p=0.030) and longer hospitalization (10 versus 6.3 days, p<0.001).

CONCLUSIONS

In SCD, there is a 39% prevalence of acute veno-occlusive involvement of the liver, a figure that is much higher than previously reported. The type of injury is mostly mixed hepatocellular-cholestatic or purely cholestatic and its course is usually benign. Liver involvement occurs more often in patients with normal spleen function and is not associated with the overall severity of the acute episode, both observations being unreported previously.

Circumstances of death in adult sickle cell disease patients

The purpose of the study was to analyze clinical and/or autopsy findings at the time of death among adults with sickle cell disease (SCD) at Howard University in Washington, DC over a 25-year period. A single physician recorded circumstances of death among 141 adult SCD patients he treated and knew well from 1976 to 2001. These findings were determined by autopsy report and/or clinical assessment. In a subset of 31 patients, autopsy records were reviewed for reports of iron deposition in liver and heart and of organ pathology. One hundred and fourteen (80.9%) of the patients had SS phenotype and 66 (46.8%) were female. The mean +/- SD age at death was 36 +/- 11 years. Leading circumstances of death included pulmonary hypertension (PHT) (26.2%), sudden death (23.4%), renal failure (22.6%), infection (18.4%), thromboembolism (14.9%), cardiac diagnoses (12.0%), cirrhosis (11.3%), pneumonia or acute chest syndrome (9.9%), bleeding (7.8%), and iron overload (7.0%). When circumstances of deaths that occurred after 1991 (n = 69) were compared to those that occurred in 1991 or earlier (n = 72), PHT (36.2% vs. 16.6%; P < 0.01) was significantly more common in 1992 or later. Significant associations were found between PHT and thromboembolism and between cirrhosis and iron overload. In this proportional mortality study of adults with SCD, PHT was the leading finding at the time of death. Thromboembolism was associated with PHT, and iron overload was associated with cirrhosis.

Hypoxic liver injury

Hypoxic liver injury is defined as a massive, but transient, increase in serum transaminase levels due to an imbalance between hepatic oxygen supply and demand in the absence of other acute causes of liver damage. It typically occurs in elderly individuals with right-sided congestive heart failure and low cardiac output. Precipitating factors include arrhythmias or pulmonary edema. Symptoms include weakness, shortness of breath, and right upper quadrant pain. Less commonly, hypoxic liver injury is seen in patients with severe hypoxemia or septic shock. Characteristically, the transaminase level is elevated 20-fold but normalizes rapidly over several days. Imaging studies reveal hypoechoic or hypodense lesions that resolve completely with reversal of the initiating event. Treatment and prognosis depend on the underlyIng disease.