Démarche diagnostique devant une hyperferritinémie

Impact of Intravenous Iron Substitution on Serum Phosphate Levels and Bone Turnover Markers-An Open-Label Pilot Study

The association between intravenous iron substitution therapy and hypophosphatemia was previously reported in patients with iron deficiency anemia. However, the extent of hypophosphatemia is thought to depend on the type of iron supplementation. We hypothesized that the intravenous application of ferric carboxymaltose and iron sucrose leads to a different longitudinal adaptation in serum phosphate levels. In this open-label pilot study, a total of 20 patients with inflammatory bowel diseases or iron deficiency anemia were randomly assigned to one of two study groups (group 1: ferric carboxymaltose, n = 10; group 2: iron sucrose, n = 10). Serum values were controlled before iron substitution therapy, as well as 2, 4, and 12 weeks after the last drug administration. The primary objective of the study was the longitudinal evaluation of serum phosphate levels after iron substitution therapy with ferric carboxymaltose and iron sucrose. The secondary objective was the longitudinal investigation of calcium, 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone, procollagen type 1 amino-terminal propeptide (P1NP), beta-CrossLaps (CTX), hemoglobin (Hb), iron, ferritin, and transferrin saturation levels. Two weeks after drug administration, phosphate levels were significantly lower (p < 0.001) in group 1 and ferritin levels were significantly higher (p < 0.001) in group 1. Phosphate levels (0.8-1.45 mmol/L) were below the therapeutic threshold and ferritin levels (10-200 ng/mL for women and 30-300 ng/mL for men) were above the therapeutic threshold in group 1. P1NP (15-59 µg/L) and CTX (<0.57 ng/mL) levels were above the therapeutic threshold in group 2. Four weeks after drug administration, significant differences were still observed between both study groups for phosphate (p = 0.043) and ferritin (p = 0.0009). All serum values except for Hb were within the therapeutic thresholds. Twelve weeks after drug administration, no differences were observed in all serum values between both study groups. Hb values were within the therapeutic threshold in both study groups. Serum 25(OH)D levels did not differ between both study groups throughout the whole study period and remained within the therapeutic threshold.

Whole-body R2∗ mapping to quantify tissue iron in iron storage organs: reference values and a genotype

AIM

To define reference values for the transverse relaxation rate (R2∗) in iron storage organs and to investigate the role of human haemochromatosis protein (HFE) genotype on iron storage.

MATERIALS AND METHODS

Whole-body magnetic resonance imaging (MRI) including a five-echo gradient-echo sequence was performed in 483 volunteers (269 men, mean age 59.3 ± 12.2 years) without clinical evidence of an iron storage disease at 1.5 T. R2∗ values were assessed for liver, spleen, pancreas, heart, bones, and brain parenchyma. The HFE genotype was determined regarding the single nucleotide polymorphisms (SNPs) rs74315324, rs1799945, rs41303501, rs1800562, rs1800730. R2∗ values were compared among participants without and with at least one mutation. R2∗ reference values were defined using volunteers without any mutation.

RESULTS

Three hundred and one participants had no mutations in any HFE SNP, 182 had at least one mutation. HFE gene mutations were distributed as (heterozygous/homozygous) rs1799945:132/9, rs1800562:33/1, and rs1800730:11/0. Mean R2∗ values ± SD (per second) in the group without mutation were: liver: 33.4 ± 12.7, spleen: 24.1 ± 13.8, pancreas: 27.2 ± 6.6, heart: 32.7 ± 11.8, bone: 69.3 ± 21.0, brain parenchyma: 13.9 ± 1.2. No significant difference in R2∗ values were found between participants with and without the HFE gene mutation for any examined iron storage organ (p_liver=0.09, p_spleen=0.36, p_pancreas = 0.08, p_heart = 0.36, p_bone = 0.98, p_brain=0.74).

CONCLUSION

Reference values of R2∗ in iron storage organs are feasible to support the diagnosis of iron storage diseases. Non-specific mutations in HFE SNPs appear not to affect the phenotype of tissue iron accumulation.

Primary varicella-zoster virus infection of the immunocompromised associated with acute pancreatitis and hemophagocytic lymphohistiocytosis: A case report

RATIONALE

Primary varicella-zoster virus (VZV) infection may be associated with hemophagocytic lymphohistiocytosis (HLH), as well as with acute pancreatitis. However, there is few data concerning the evolution and the optimal treatment of these rare associations.

PATIENT CONCERNS

A 57-year-old immunocompromised woman, who was treated for chronic lymphocytic leukemia 3 years prior to admission, was hospitalized with abdominal pain revealing severe acute pancreatitis. The day after admission, a pruritic rash appeared on her face, trunk, and limbs, sparing the palmoplantar regions. At the same time, fever, thrombocytopenia (27 × 109/L), major hyperferritinemia (11,063 μg/mL), hypertriglyceridemia (2.56 mmol/L) and elevated lactate dehydrogenase levels (1441 IU/L) suggested HLH.

DIAGNOSIS

The diagnosis of chickenpox (varicella) was established. Primary VZV infection was then confirmed: cutaneous and plasma VZV polymerase chain reactions were positives, VZV serology was negative for IgG.

INTERVENTIONS

Treatment with aciclovir was started intravenously after the onset of the rash, for a total of 10 days. A 48-h surveillance in intensive care was carried out.

OUTCOMES

Acute pancreatitis and biological abnormalities evolved favorably under aciclovir. Platelet count was normalized 6 days after admission to hospital.

LESSONS

A favorable outcome of primary VZV infection associated with severe acute pancreatitis and probable HLH in an immunocompromised patient is possible with aciclovir alone.

Iron in the General Population and Specificities in Older Adults: Metabolism, Causes and Consequences of Decrease or Overload, and Biological Assessment

Iron is involved in many types of metabolism, including oxygen transport in hemoglobin. Iron deficiency (ID), ie a decrease in circulating iron, can have severe consequences. We provide an update on iron metabolism and ID, highlighting the particularities in older adults (OAs). There are three iron compartments in the human body: 1) the functional compartment, which consists of heme proteins including hemoglobin, myoglobin and respiratory enzymes; 2) iron reserves (IR), which consist mainly of liver stocks and are stored as ferritin; and 3) transferrin. There are two types of ID. Absolute ID is characterized by a decrease in IR. Its main pathophysiological mechanism is bleeding, which is often digestive and can be due to neoplasia, frequent in OAs. Biological assessment shows low serum ferritin and transferrin saturation (TS) levels. Furthermore, hypochromic microcytic anemia is frequent, and the serum-soluble transferrin receptor (sTfR) level is high. Functional ID, in which IR are high or normal, is due to inflammation, which is also frequent in OAs, particularly in its chronic form. Biological assessments show high serum ferritin, normal or low TS, and normal sTfR levels. Moreover, C-reactive protein is elevated, and there is moderate non-regenerative non-macrocytic anemia. The main characteristics of iron metabolism anomalies in the elderly are the high frequency of ID (20% of ID with anemia in adults ≥85 years) and the severity of its consequences, which include cognitive impairment in case of ID or iron overload and decrease of physical activity in case of ID. In conclusion, causes of ID are frequently intertwined in OAs as a result of the polymorbidity that characterizes them. ID can have dramatic consequences, especially in frail OAs. Thus, measuring the appropriate biological markers prevents errors in the positive diagnosis of ID type, clarifies etiology, and informs treatment-related decision-making.

[Gaucher Disease type 1 mimicking immune thrombocytopenia: Role of hyperferritinemia and hypergammaglobulinemia in the initial evaluation of an isolated thrombopenia]

INTRODUCTION

Gaucher disease type 1 is a rare genetic disease. It can cause thrombocytopenia. Current guidelines do not support bone marrow examination in front of isolated thrombocytopenia if no evidence suggests malignant hemopathy. This strategy aiming at sparing unnecessary investigations makes such rare diseases more difficult to diagnose.

CASE REPORT

A 31-year-old woman was diagnosed with immune thrombocytopenia according to current guidelines. She presented later with mild splenomegaly. Bone marrow aspirate smears showed Gaucher cells. Gaucher disease was then confirmed. Looking backward, initial biological clues (hyperferritinemia, hypergammaglobulinemia) should have enabled to consider the diagnosis.

CONCLUSION

Gaucher disease type 1 can be responsible for apparently isolated thrombocytopenia. The disease must be looked for if the thrombocytopenia is associated with unexplained hypergammaglobulinemia or hyperferritinemia. Diagnosing immune thrombocytopenia without bone marrow sample requires to systematically pay attention to any clinical or biological abnormality, not to ignore rare differential diagnoses.

[A microcytic sideroblastic anemia successfully treated with B6 vitamin]

INTRODUCTION

Sideroblastic anemia is a rare cause of microcytic anemia, which is characterized by ring sideroblasts on bone marrow aspirate. This anemia can be congenital or acquired.

CASE REPORT

We report the case of an alcoholic 49-year-old man who presented with a severe microcytic sideroblastic anemia related to pyridoxine (B6 vitamin) deficiency. Acid folic deficiency was associated. The blood count normalized within one month after vitamin supplementation.

CONCLUSION

Pyridoxine deficiency must be sought in sideroblastic anemia in patients at risk.

Monitoring Iron Overload: Relationship between R2* Relaxometry of the Liver and Serum Ferritin under Different Therapies

Objective:

The objective of this study was to evaluate the relationship between hepatic magnetic resonance imaging (MRI) with R2* relaxometry and serum ferritin in therapy monitoring of patients with iron overload. Further, a possible influence of the chosen therapy (phlebotomy or chelation) was assessed.

Materials and Methods:

We retrospectively evaluated 42 patients with baseline and follow-up R2* relaxometry and determination of serum ferritin before and during therapeutic phlebotomy or iron chelation therapy or watchful waiting, respectively. Linear regression analysis was used to analyze the correlation between changes of R2* and serum ferritin. Regression lines for different groups were compared with analysis of covariance.

Results:

We found a moderate positive statistical correlation (r = 0.509) between serum ferritin and R2*, a moderate positive correlation between absolute R2* changes and serum ferritin changes (r = 0.497), and a strong correlation for percentage changes (r = 0.712). The correlation analysis between relative changes of R2* and serum ferritin for the different therapies resulted in a strong correlation between phlebotomy and chelation (r = 0.855/0.727) and a moderate for no applied therapy (r = 0.536). In 22/92 paired examinations, a discordance of R2* and ferritin was found, particularly involving patients under chelation.

Conclusions:

Despite the good correlation between serum ferritin and R2* relaxometry in monitoring iron overload, treatment response may be misinterpreted when only serum ferritin is considered. Although ferritin is an acceptable and far cheaper tool for monitoring, MRI should be performed for confirmation, especially in case of unexpected ferritin changes, particularly under chelation therapy.

Diagnosis of hyperferritinemia in routine clinical practice

The discovery of hyperferritinemia is often fortuitous, revealed in results from a laboratory screening or follow-up test. The aim of the diagnostic procedure is therefore to identify its cause and to identify or rule out hepatic iron overload, in a three-stage process. In the first step, clinical findings and several simple laboratory tests are sufficient to detect four of the most frequent causes of high ferritin concentrations: alcoholism, inflammatory syndrome, cytolysis, and metabolic syndrome. None of these causes is associated with substantial hepatic iron overload. If transferrin saturation is high (> 50%), hereditary hemochromatosis will be considered in priority. In the second phase, rarer diseases will be sought. Among them, only chronic hematologic diseases (acquired or congenital) and excessive iron intake or infusions (patients on chronic dialysis and high-level athletes) are at risk of iron overload. In the third stage, if a doubt persists about the cause or if the ferritin concentration is very high or continues to rise, it is essential to verify the hepatic iron concentration to rule out overload. The principal examination to guide diagnosis and treatment is hepatic MRI to assess its iron concentration. It is essential to remember that more than 40% of patients with hyperferritinemia have several causes simultaneously present.