Unexplained iron deficiency in idiopathic and heritable pulmonary arterial hypertension.

BACKGROUND: Anaemia is common in left heart failure and is associated with a poorer outcome. Many patients with pulmonary arterial hypertension (PAH) are anaemic or iron-deficient. This study was performed to investigate the prevalence of iron deficiency in PAH and to identify possible causes. METHODS: All patients with idiopathic or heritable PAH diagnosed in 1995-2008 were identified. Controls were selected from patients with chronic thromboembolic pulmonary hypertension (CTEPH). Full blood counts were examined and any abnormality was investigated. Patients were excluded if they had a cause for iron deficiency. The prevalence study was based on 85 patients with idiopathic PAH and 120 with CTEPH. A separate group of 20 patients with idiopathic PAH and 24 with CTEPH with matching haemodynamics were prospectively investigated for serum factors affecting iron metabolism. RESULTS: The prevalence study identified a point prevalence of unexplained iron deficiency of 50% in premenopausal women with idiopathic PAH compared with 8% in premenopausal women with CTEPH (p=0.002); 14% in postmenopausal women with idiopathic PAH compared with 6% in postmenopausal women with CTEPH (p=0.16); 28% in men with idiopathic PAH men compared with 2% in men with CTEPH (p=0.002); and 60% in patients with heritable PAH. The serum study showed that patients with idiopathic PAH had lower serum iron and transferrin saturations than those with CTEPH. Interleukin-6 levels correlated with iron levels (r=-0.6, p=0.006) and transferrin saturations (r=-0.68, p=0.001) in idiopathic PAH but not in CTEPH. CONCLUSIONS: The prevalence of unexplained iron deficiency is significantly higher in idiopathic PAH than in CTEPH. This may be linked to interleukin-6.

Hypothesis: Pentoxifylline is a potential cytokine modulator therapeutic in COVID-19 patients.

We propose a new hypothesis that the established drug pentoxifylline deserves attention as a potential repurposed therapeutic for COVID-19. Pentoxifylline is an immunomodulator with anti-inflammatory properties. It is a nonselective phosphodiesterase inhibitor and through Adenosine A2A Receptor-mediated pathways reduces tumor necrosis factor alpha, interleukin 1, interleukin 6, and interferon gamma and may act to reduce tissue damage during the cytokine storm host response to SARS-CoV-2 infection. This agent has been used clinically for many years and has a favorable profile of safety and tolerability. Pre-clinical data support pentoxifylline as effective in cytokine-driven lung damage. Clinical studies of pentoxifylline in radiation and cytokine-induced lung damage in humans are positive and consistent with anti-inflammatory efficacy. Pentoxifylline is a readily available, off-patent and inexpensive drug, suitable for large-scale use including in resource-limited countries. Current trials of therapeutics are largely focused on the inhibition of viral processes. We advocate urgent randomized trials of pentoxifylline for COVID-19 as a complementary approach to target the host responses.

Blunted increase in serum hepcidin as response to oral iron in HFE-hemochromatosis.

BACKGROUND: HFE hemochromatosis (HFE-H) is the most common and well-defined inherited cause for iron-related morbidity and mortality. Majority of patients with HFE-H are homozygote for C282Y mutation. Recent studies suggest that iron accumulation in most types of hemochromatosis is due to deficiency of hepcidin, a central iron regulator. However, the precise link between hepcidin levels and iron absorption in HFE-H patients has been poorly understood. AIM: To measure hepcidin response to oral iron challenge (200 mg ferrous sulphate), in HFE-H (C282Y/C282Y) patients and compare with healthy controls (HCs). METHODS: Nine patients with C282Y/C282Y HFE-H along with 15 HC were recruited for the study. All HFE-H were iron depleted and studied at a time distant to phlebotomy. Hepcidin was measured using a published immunoassay method after ingestion of 65 mg oral iron challenge. Serum iron, ferritin and transferrin saturation were measured using standard methods. The area under the curve was calculated and compared between the two groups. RESULTS: The basal serum hepcidin levels in patients with HFE-H were significantly low as compared with HC (P=0.0002). Incremental serum hepcidin response seen in HC reached significance at 4 h post iron challenge (P=0.0085) returning to baseline only at 24 h. There was no significant hepcidin response in HFE-H at 4 h (P=0.294). The overall hepcidin response was significantly lower in HFE-H compared with HC (area under the curve: P=0.0127). CONCLUSION: Failure to mount a rapid hepcidin response to an oral iron challenge is the key mechanisms of iron accumulation despite prevailing excess body iron in patients with HFE-H with C282Y/C282Y mutation.

Presence of hepcidin-25 in biological fluids: bile, ascitic and pleural fluids.

AIM: To examine body fluids such as ascitic fluid (AF), saliva, bile and pleural effusions for the presence of hepcidin using a novel radioimmunoassay (RIA). METHODS: Serum samples were collected from 25 healthy volunteers (mean age: 36 +/- 11.9 years, 11 males, 14 females). In addition bile was obtained from 12 patients undergoing endoscopic retrograde cholangiopancreatography (mean age: 66.9 +/- 16.7 years, M:F = 5:7). Saliva was collected from 17 healthy volunteers (mean age: 35 +/- 9.9 years, M:F = 8:9). Pleural and AF were collected from 11 and 16 patients [(mean age: 72 +/- 20.5 years, M:F = 7:4) and (mean age: 67.32 +/- 15.2 years, M:F = 12:4)], respectively. All biological fluid samples (serum, exudative and transudative fluids) were tested for the presence of hepcidin-25 molecule using RIA. RESULTS: Hepcidin-25 was detected in all biological fluids tested. The mean +/- SD hepcidin-25 in serum was 15.68 +/- 15.7 ng/mL, bile 7.37 +/- 7.4 ng/mL, saliva 3.4 +/- 2.8 ng/mL, exudative fluid 65.64 +/- 96.82 ng/mL and transudative fluid 14.1 +/- 17.8 ng/mL. CONCLUSION: We provide clear evidence that hepcidin-25 is present in bile, saliva, pleural and ascitic fluids. Hepcidin is likely to play a role here in innate immunity.

Hepcidin levels in hereditary hyperferritinemia: Insights into the iron-sensing mechanism in hepatocytes.

AIM: To study the role of hepcidin in hereditary hyperferritinemia cataract syndrome (HHCS). METHODS: Six patients from two families with HHCS, confirmed by genetic analysis showing A to G mutation at position +40 in the L-ferritin gene, were recruited to undergo serum hepcidin and prohepcidin measurements using radioimmunoassay and enzyme linked immunoassay, respectively, and measurements were compared with levels in serum from 25 healthy volunteers (14 females), mean age 36 +/- 11.9 years. RESULTS: The serum hepcidin and prohepcidin levels in patients with HHCS were 19.1 +/- 18.6 and 187 +/- 120.9 ng/mL, respectively. Serum ferritin was 1716.3 +/- 376 microg/L. Liver biopsy in one patient did not show any evidence of iron overload. Serum hepcidin and prohepcidin values in healthy controls (HCs) were 15.30 +/- 15.71 and 236.88 +/- 83.68 ng/mL, respectively, while serum ferritin was 110 +/- 128.08 microg/L. There was no statistical difference in serum hepcidin level between the two cohorts (19.1 +/- 18.6 ng/mL vs 15.30 +/- 15.71 ng/mL, P = 0.612) using two-tailed t-test. CONCLUSION: Serum hepcidin levels in HHCS patients is similar to that in HCs. Our study suggests that circulating ferritin is not a factor influencing hepcidin synthesis and does not have a role in the iron-sensing mechanism in hepatocytes.