Acute Intravascular Hemolysis Research Articles

Acalypha indica induced acute oxidative haemolysis and methaemoglobinaemia: two case reports

BackgroundHerbal products and traditional remedies are commonly used by individuals worldwide for the management of common ailments, even though most are not without risks. Acalypha indica is a popular medicinal plant consumed in some Asian countries.Case presentationThis case report presents a 40-year-old previously unevaluated Sri Lankan female and her 8-year-old son who presented with severe glucose-6-phosphate dehydrogenase (G6PD) deficiency related acute intravascular oxidative haemolysis and methaemoglobinaemia precipitated by Acalypha indica consumption, successfully managed with supportive care and blood transfusion.ConclusionsThis case highlights the potential hemolytic and methaemoglobinaemic effects of ingesting oxidant herbal products and the importance of considering such exposures in patients presenting with hemolysis and multiorgan involvement, particularly in communities where herbal product intake is popular. Healthcare providers should be aware of the risks associated with traditional remedies and maintain a high index of suspicion to ensure prompt recognition and appropriate management.

Blood Group Discrepancy in a Donor Due to a Rare Ax/Aweak Subgroup Phenotype with ABO*AW.31.01/*O.01.75 Genotype

ABSTRACT The most crucial blood group system in transfusion medicine is still the ABO system. Any unresolved discrepancy could result in the patient receiving blood that is incompatible and could trigger acute intravascular hemolysis. ABO subgroups are one of the astounding differences in blood grouping. The amount of A and B antigens carried by red blood cells and present in secretion varies depending on the ABO subgroup phenotype. Clinically, A1 and A2 are the two most frequently observed subtypes. Many weaker A subgroups have been described, including A3, Axe, am, and el. This example involves an Indian male donor who was initially misclassified as a Group O individual before being identified as an Ax/Aweak subgroup phenotypically. The next-generation sequencing defined the genotype of this case as ABO*AW.31.01/*O.01.75.

A fatal case of acute copper sulphate poisoning presenting with methaemoglobinemia and intravascular haemolysis: a case report

Copper sulphate is a common industrial chemical that is rarely used for suicide. Ingestion of more than one gram of copper sulphate causes features of toxicity, mainly severe gastrointestinal tract erosions, methaemoglobinemia, acute kidney injury, intravascular haemolysis, and acute hepatitis. A dose of more than 10g is lethal. The management is mainly supportive. Copper chelation with penicillamine, edetate calcium disodium (EDTA) and British anti-Lewisite (BAL) can be used to minimize the toxicity. Exchange transfusion for severe methemoglobinemia has been attempted with variable success.We report a lethal case of poisoning with 75g of copper sulphate resulting in severe methaemoglobinemia, intravascular haemolysis, gastrointestinal bleeding and multi-organ failure. Exchange transfusion was carried out without success and the patient succumbed to death on the third day of the poisoning. Though it is rare, the fatality of copper sulphate poisoning necessitates proper knowledge about manifestations and management options.

Caspase-1 As a Therapeutic Target in Intravascular Hemolysis-Induced Microvascular Inflammation and Occlusive Processes

Hemolytic anemias, such as sickle cell disease (SCD), are a group of acute and acquired conditions characterized by the accelerated destruction of red blood cells (RBC). Intravascular hemolysis (IVH), or RBC lysis within the bloodstream, incurs the release of damage-associated molecular patterns (DAMPs), trigging cell activation and immune responses. Caspase-1 (Casp-1), a protease enzyme, plays a critical role during inflammatory processes by initiating programed cell death and promoting the cleavage of pro-interleukin (IL)-1β into its active form, IL-1β, through inflammasome assembly. Here, we aimed to elucidate the complex mechanisms involved in IVH-induced inflammation, leukocyte-endothelium interactions, and microvascular dynamics. Acute IVH was induced in C57BL/6 mice (HEM) by the injection of sterile water (i.v., 150 µl), and control mice received i.v. saline (CON) (n=3-8 per group). Intravital microscopy was performed at 15 min post IVH induction on the cremaster muscle of mice to quantify venular leukocyte (WBC) rolling and adhesion, and non-invasive laser Doppler flowmetry (LDF) measured blood perfusion in the murine pelvis microvasculature. Blood samples were collected at 1-hour post-IVH for ELISA and flow cytometry analyses. Immortalized human endothelial cells (HUVEC; n=7 per group) were stimulated with heme or S100A8 for 3 hours. HEM mice demonstrated significantly increased plasma heme (P<0.0001) and cell-free hemoglobin (P<0.001), in association with significantly decreased plasma haptoglobin (P<0.05), compared to CON mice, thereby confirming the occurrence of IVH. Furthermore, HEM mice exhibited significantly increased plasma concentrations of the S100A8 alarmin (P<0.001) and IL1-β (P<0.001), as well as augmentations (P<0.001) in plasma TNF-ɑ and IL-6 levels. Flow cytometry was used to measure active Casp-1 in neutrophils and monocytes of mice using the FAM-FLICA probe. FLICA staining was significantly higher in the neutrophils (P<0.05) and monocytes (P<0.05) of HEM mice, compared to CON mice, implying Casp-1 activation in these cell subsets. WBC-endothelium interactions are a hallmark of vaso-occlusion in SCD. HEM mice exhibited elevated venular WBC rolling and adhesion to the endothelium, compared to CON mice (P<0.001), as previously shown (Almeida et al., 2015; PMID: 26019278). In addition, IVH significantly reduced the velocity of microvascular blood flow in mice (P<0.001), and impaired perfusion (P<0.001). To address the role of IVH-induced Casp-1 activation in microvascular dynamics, mice received i.p. administrations of the Casp-1 inhibitor, YVAD, at 1 hour prior to induction of IVH, or not, and were subjected to intravital microscopy or LDF. Interestingly, the inhibition of Casp-1 significantly abrogated IVH-induced WBC rolling (P<0.01) and adhesion to vessel walls (P<0.05) in HEM mice and significantly improved microvascular blood perfusion and flow velocity (P<0.05), suggesting a role for Casp-1 activation in the WBC-endothelium and occlusive interactions observed (See Figure). We then evaluated how heme and S100A8 may induce endothelial cell activation, as these DAMPs were found elevated in the plasma of HEM mice. As expected, compared to unstimulated HUVEC, heme induced endothelial cell activation in vitro, as shown by higher expressions of ICAM-1 (P<0.05), VCAM-1 (P<0.01) and E-selectin (P<0.01), and increased Casp-1 activity (P<0.01). In turn, S100A8 alone significantly elevated ICAM-1 (P<0.05) and E-selectin (P<0.01) expressions on HUVEC, as well as IL-1β release (P<0.001), however no significant increase in Casp-1 activity was observed. HUVEC, when pre-treated with YVAD, displayed a significant reduction in S100A8-induced E-selectin expression (P<0.05), but neither ICAM-1 nor VCAM-1 expression were significantly decreased. In contrast, no changes in the expressions of these adhesion molecules were observed in heme-stimulated cells after YVAD treatment. Taken together, these findings suggest that targeting caspase-1 activation and its associated pathways may represent a potential therapeutic intervention to mitigate the adverse inflammatory and microvascular effects of IVH, a disease mechanism that occurs in severe hemolytic anemias such as SCD.

Hemolysis and Free Heme Impact Therapeutic Activity of Anti-CD20 Antibody

Hemolysis is a process of destruction of erythrocytes that can occur in different hereditary or acquired pathologies. It is accompanied by release of hemoglobin and heme, which both manifest potent pro-oxidative and pro-inflammatory activities. If released in large quantities hemoglobin and heme can directly contribute to systemic inflammation and tissue injury in hemolytic diseases. Moreover, it was demonstrated that heme binds to a significant fraction (ca. 10 %) of human antibodies (Abs) and this binding can result in considerable functional changes. Thus, heme-bound human IgG acquire reactivity towards a large set of unrelated proteins, including autoantigens. In a previous study we observed that 14 % of a repertoire of 117 clinical-stage therapeutic mAbs are able to bind heme and as a result they acquired autoreactivity and polyreactivity. Among these Abs some are specific for CD20 and used in lymphoma therapy (e.g. Rituximab). Importantly, therapeutic mAbs can be administered in patients with ongoing hemolysis. Thus, it is of critical importance to decipher molecular mechanism and functional consequences of interaction of heme with therapeutic mAbs and understand how the therapy of lymphoma can be affected by underling hemolysis and heme release. The present study has the following objective: to elucidate the effect of heme on the therapeutic activity of anti-CD20 therapy in in vitro and in vivo models of B cell lymphoma. Effect of heme on anti-CD20 therapeutic Abs was assessed by i) binding assays - ELISA, western blot; protein microarrays; absorbance spectroscopy; surface plasmon resonance, and ii) molecular modeling. The impact of heme on functional and therapeutic activity of Rituximab was analyzed by i) site-directed mutagenesis; ii) flow cytometry; iv) in vitro and in vivo models of human B cell lymphoma. Our data reveled molecular and functional details about the interaction of heme with Rituximab and other anti-CD20 Abs. Thus, we characterized the interaction of Abs with heme, and identified in case of Rituximab the putative binding site for heme that overlapped with antigen binding site. By using a protein array with >9800 human proteins, we identified the target proteins of heme-bound Rituximab. A mouse model of human B cell lymphoma revealed that the therapeutic activity of Rituximab was compromised following exposure to cell free heme under condition of acute intravascular hemolysis. Our study delineates that a fraction of currently used therapeutic mAbs show high sensitivity to heme and their therapeutic activity can be compromised under hemolytic conditions. This finding suggests that therapeutic interventions that reduce free heme and /or intravascular hemolysis should precede therapy with these Abs. Moreover, we identified sequence features of Abs that determine the sensitivity to heme. This finding can help to reduce sensitivity of heme of therapeutic Abs by protein engineering.

Intravascular hemolysis triggers NAFLD characterized by a deregulation of lipid metabolism and lipophagy blockade.

Intravascular hemolysis is a common feature of different clinical entities, including sickle cell disease and malaria. Chronic hemolytic disorders are associated with hepatic damage; however, it is unknown whether heme disturbs lipid metabolism and promotes liver steatosis, thereby favoring the progression to nonalcoholic fatty liver disease (NAFLD). Using an experimental model of acute intravascular hemolysis, we report here the presence of liver injury in association with microvesicular lipid droplet deposition. Hemolysis promoted serum hyperlipidemia and altered intrahepatic triglyceride fatty acid composition, with increments in oleic, palmitoleic, and palmitic acids. These findings were related to augmented expression of transporters involved in fatty acid uptake (CD36 and MSR1) and deregulation of LDL transport, as demonstrated by decreased levels of LDL receptor and increased PCSK9 expression. Hemolysis also upregulated hepatic enzymes associated with cholesterol biosynthesis (SREBP2, HMGC1, LCAT, SOAT1) and transcription factors regulating lipid metabolism (SREBP1). Increased LC3II/LC3I ratio and p62/SQSTM1 protein levels were reported in mice with intravascular hemolysis and hepatocytes stimulated with heme, indicating a blockade of lipophagy. In cultured hepatocytes, cell pretreatment with the autophagy inductor rapamycin diminished heme-mediated toxicity and accumulation of lipid droplets. In conclusion, intravascular hemolysis enhances liver damage by exacerbating lipid accumulation and blocking the lipophagy pathway, thereby promoting NAFLD. These new findings have a high translational potential as a novel NAFLD-promoting mechanism in individuals suffering from severe hemolysis episodes. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

A Case of Acute Intravascular Hemolysis During Dialysis: A Quiz

A Case of Acute Intravascular Hemolysis During Dialysis: A Quiz

Mild forms of thrombotic microangiopathy in patients with advanced pancreatic cancer receiving gemcitabine and nab-paclitaxel.

Thrombotic microangiopathy (TMA) is an uncommon complication that may occur in cancer patients usually as an expression of cancer-associated coagulopathy or due to drug-related toxicity. The clinical spectrum of TMA may vary from an incidental laboratory finding in cancer outpatients to potentially severe life-threatening clinical forms with organ involvement requiring prompt recognition and multidisciplinary evaluation. We present the clinical characteristics and outcomes of four patients with advanced pancreatic cancer with acute non-immune intravascular haemolysis compatible with microangiopathic acute haemolytic anaemia associated with mild thrombocytopenia during long-term gemcitabine and nab-paclitaxel treatment. Abnormal blood parameters (all four cases) and renal involvement (one case) were reversed with a conservative approach and chemotherapy discontinuation. One patient required a short hospitalization while the other three were managed as outpatients. The rapid reversibility of the blood abnormalities supported gemcitabine dose-related toxicity as the most likely aetiologic mechanism and demonstrates the current challenges in daily long-term cancer survivor care. Clinicians must take into account TMA in the differential diagnosis of acute anaemia with or without thrombocytopenia and organ damage, since adequate recognition and early treatment discontinuation allow effective outpatient management and favourable patient outcomes.

Acute Haemolysis Precipitating Rhabdomyolysis and Acute Kidney Injury in a Newly Diagnosed G6PD Deficiency: A Case Report

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is a common X-linked genetic condition among Malaysians that have largely caused acute intravascular haemolysis. In G6PD deficient children, the phenomenon of rhabdomyolysis and myoglobinuria is a rare complication as muscle has more resistant to undergo acute myolysis. A 22-month-old Malay child was presented with severe anaemia following with ingestion of large amount of fava beans. He then developed into acute kidney injury together with the laboratory findings of intravascular haemolysis, rhabdomyolysis, and the presence of multi-systems bloods derangement. He showed positive response to hyperhydration, haemodialysis and blood transfusions. Bangladesh Journal of Medical Science Vol. 21 No. 03 July’22 Page: 741-744

Heme Induced Progressive Loss of Endothelial Protein C Receptor Promotes Development of Chronic Kidney Disease in Sickle Cell Disorders

Chronic kidney disease (CKD), widespread among the individuals with sickle cell disease (SCD), is a major contributor to early death in this patient population. The progressive deterioration of renal health in SCD is associated with chronic persistent intravascular hemolysis leading to anemia. We have previously reported that extracellular heme, released during acute intravascular hemolysis triggers clinically relevant acute kidney injury (AKI) in SCD mice (SS) (Blood (2020) 135 (13): 1044-1048). Although AKI is reversible, it is considered as a risk factor for CKD. The mechanistic approach elucidating the hemolysis driven pathogenesis of AKI-to-CKD transition in SCD is unknown. We found that CKD develops in the SS mice by progressive (1-10 months of age) increase in albuminuria (urinary albumin and creatinine ratio, uACR) and decrease in glomerular filtration rate (GFR) (n=5; p<0.001). Histopathology of the kidney showed age-dependent deterioration in renal peritubular vascular congestion in SS mice compared to that of the AA mice. Alongside, Evan's blue extravasation experiments showed that the SS mice are susceptible to vascular leakage that is correlated positively with age (Pearson r=0.98, p<0.001) and negatively with anemia (Pearson r= -0.46, p<0.05). We hypothesized that multiple acute hemolytic events may instigate persistent endothelial damage that ensues CKD development in SCD. To test this hypothesis, we intravenously infused vehicle or heme (14 μmoles/kg body weight; 5 times on alternate days) to 1-month old SS mice and monitored for 3 weeks following first heme injection. These mice developed severe albuminuria (n=5; p<0.01) with substantial loss of GFR (n=5; p<0.001), indicating heme induced CKD development. Next, we used ultrasound super-resolution (USR) imaging technology to determine renal microvascular changes in older SS mice (6-months) without heme challenge and in young SS mice (1-month) challenged with heme. Analysis of the USR data showed reduced renal blood volume (rBV) and substantial loss of vessel density in renal cortex as well as in corticomedullary areas of the older SS mice compared to the age-matched AA mice. Accordingly, multiple heme challenge reduced rBV and vessel density extensively in young SS mice comparable to the older SS mice without heme challenge. Since endothelial protein C receptor (EPCR) maintains vascular barrier integrity by activating protease activated receptor-1 (PAR1) signaling in the endothelium, we tested whether alterations in EPCR expression contribute to progressive endothelial damage in SS mice during CKD development. Using immunofluorescence microscopy, we determined that renal endothelium lacks expression of EPCR in older SS mice while younger SS mice retains EPCR cellular expression. In corroboration, infusion of heme in younger SS mice results in loss of renal endothelial EPCR. Shedding of EPCR from endothelium often results in a soluble form of EPCR (sEPCR). We found that SS mice had higher plasma levels of soluble EPCR (sEPCR) compared to their AA counterparts. While age dependent increase in plasma and urinary sEPCR were evident in SS mice (n=6; p<0.01), infusion of heme in younger SS mice results in significant increase in plasma sEPCR (n=6; p<0.01). In consistent with the mouse data, we discovered that the plasma sEPCR was significantly elevated in SCD patients compared to normal individuals (n=8-16; p<0.05). Moreover, the plasma sEPCR was significantly associated with the baseline albuminuria in a cohort of SCD patients (n=16; Pearson r=0.64; p<0.01). This study supports the conclusion that multiple hemolytic events may trigger CKD development in SCD by gradual loss of renal microvascular EPCR expression. Clinically, the sEPCR can be developed as risk factor for sickle CKD. Finally, our data suggest that restoration of EPCR function may protect SCD patients from CKD. DisclosuresNo relevant conflicts of interest to declare.

Acute intravascular hemolysis in the critical phase of severe dengue

Acute intravascular hemolysis in the critical phase of severe dengue

Intravascular hemolysis triggers ADP-mediated generation of platelet-rich thrombi in precapillary pulmonary arterioles.

Patients with hereditary or acquired hemolytic anemias have a high risk of developing in situ thrombosis of the pulmonary vasculature. While pulmonary thrombosis is a major morbidity associated with hemolytic disorders, the etiological mechanism underlying hemolysis-induced pulmonary thrombosis remains largely unknown. Here, we use intravital lung microscopy in mice to assess the pathogenesis of pulmonary thrombosis following deionized water-induced acute intravascular hemolysis. Acute hemolysis triggered the development of αIIbβ3-dependent platelet-rich thrombi in precapillary pulmonary arterioles, which led to the transient impairment of pulmonary blood flow. The hemolysis-induced pulmonary thrombosis was phenocopied with intravascular ADP- but not thrombin-triggered pulmonary thrombosis. Consistent with a mechanism involving ADP release from hemolyzing erythrocytes, the inhibition of platelet P2Y12 purinergic receptor signaling attenuated pulmonary thrombosis and rescued blood flow in the pulmonary arterioles of mice following intravascular hemolysis. These findings are the first in vivo studies to our knowledge to suggest that acute intravascular hemolysis promotes ADP-dependent platelet activation, leading to thrombosis in the precapillary pulmonary arterioles, and that thrombin generation most likely does not play a significant role in the pathogenesis of acute hemolysis-triggered pulmonary thrombosis.

Acute Hemolytic Transfusion Reaction Due to Anti-c Rhesus Antibody in a Patient With Subdural Hematoma: A Case Report Emphasizing the Shortcoming of Spin Cross-Match

The Rh blood group system is a complex blood group which includes different antigen specificities such as c antigen. Anti-c antibody is associated with both acute and delayed hemolytic transfusion reactions as well as hemolytic disease of the newborn (HDN). Rh mediated hemolytic transfusion reactions (HTR) are mostly immunoglobulin G (IgG) mediated and results in extravascular hemolysis and delayed HTR (DHTR). However, we are presenting a case of acute intravascular hemolytic transfusion reaction due to anti-c in a patient with acute subdural hematoma. A 77-year-old woman was referred to our hospital with a loss of conscious and left-sided hemiparesis. After an emergency MRI, she was diagnosed with Acute Subdural hematoma, and an emergency craniotomy was performed. Since Acute Subdural hematoma is a neurosurgery emergency, laboratory technician performed an Immediate-spincrossmatchedd for blood bag to preserve time. During the transfusion of the first packed cell, the patient developed severe hypotension and tachycardia. Thus, the transfusion was stopped. Laboratory results raised the suspicion of an Acute Intravascular Hemolysis. Antibody identification revealed that the patient had an irregular blood phenotype (C2+/c-/E-/e3+/K-), and the presence of alloantigen-c Rh antibody confirmed the suspicion of HTR. In patients with multi transfusion history and pregnant women, pre-transfusion screening of irregular antibodies must be performed. The immediate spincrossmatchh must be prevented in patients with a history of multi transfusions, even in emergency situations.

Exploring association between MBL2 gene polymorphisms and the occurrence of clinical blackwater fever through a case\u2013control study in Congolese children

BackgroundBlackwater fever (BWF), one of the most severe and life-threatening forms of falciparum malaria, is characterized by acute massive intravascular haemolysis, often leading to acute renal failure. Thus far, the genetics of the underlying susceptibility to develop BWF is not fully elucidated. Deficiency in the MBL protein, an important component of the innate immune system, has previously been suggested to be a susceptibility factor for the development of severe malaria. This study aimed to evaluate the association between MBL2 gene polymorphisms, known to affect the MBL protein level/activity, and the occurrence of BWF among Congolese children.MethodsThis is a case–control study. Cases were patients with BWF, whereas controls, matched for gender and age, had uncomplicated malaria (UM). Dried blood spot was collected for genotyping.ResultsA total of 129 children were screened, including 43 BWF and 86 UM. The common allele in BWF and UM was A, with a frequency of 76.7 and 61.0%, respectively (OR: 2.67 (0.87–829) and p = 0.079). The frequency of the C allele was 18.6 and 29.1% in BWF and UM groups, respectively, with p = 0.858. Not a single D allele was encountered. Genotype AA was at higher risk for BWF whereas genotypes A0 (AB and AC) were over-represented in UM group (OR: 0.21 (0.06–0.78)) with p = 0.019. Nine haplotypes were observed in this study: 3 high MBL expression haplotypes and 6 low MBL expression haplotype. One new haplotype HYPC was observed in this study. None of these haplotypes was significantly associated with BWF.ConclusionThis pilot study is a preliminary research on MBL2 gene and infectious diseases in DRC. The study results show a higher risk for BWF in AA. This suggests that future studies on BWF should further investigate the contribution of a strong immune response to the occurrence of BWF.

PF744 SPECTRUM OF PARVOVIRUS B19 INFECTION IN CHILDREN WITH SICKLE CELL DISEASE: ATYPICAL PRESENTATIONS

Background:Human Parvovirus B19 (P‐B19) infection is known to cause aplastic crisis in sickle cell disease (SCD) patients. However, few studies have reported rare unusual complication of Parvovirus in SCD.Aims:To describe the demographic and clinical characteristics of Parvovirus B19 infection in hospitalized children with SCD admitted to Sultan Qaboos Universirty Hospital (SQUH) throughout the period (2009–2018), with special emphasis on atypical presentations.Methods:Descriptive retrospective study.Results:Out of 4688 admission episodes of pediatric patients with SCD throughout the duration of study, 108 patients (61 males &amp; 47 females) were diagnosed with Parvovirus B12 infection evidenced by positive PCR, with an age ranging from 18 months to 13.5 years. Parvovirus B19 infection accounts for 2.3% of the total admissions in our institution. It is the 4th commonest cause of hospitalizing children with SCD, just after painful crisis, acute chest syndrome, and fever without focus respectively. Out of the 108 cases, 94 children presented with isolated classical aplastic (erythroblastopenic) crisis, associated with variable grades of fever +/‐ joint pains. The majority of patients required transfusion once, although 20 of them needed twice or more transfusions. Atypical presentations were encountered in 14 patients (12.9%). The commonest is splenic sequestration coupled with aplastic crisis and marked reticulocytopenia (12 cases). The first two cases were siblings diagnosed in 2010. Since then, this complication has been increasingly recognized in our patients and we have noted a familial tendency to develop Parvovirus B19‐induced acute splenic sequestration, indicating a possible genetic predisposition to this complication, which is seen in our cohort in a much higher frequency compared to the published literature.Severe Parvovirus B19‐induced bone marrow failure was seen in a 7 year‐old male patient. This boy developed marked pancytopenia associated with protracted high grade fever, acute chest syndrome and severe painful crisis. The only positive culprit was Parvovirus B19 which was persistently positive with a very high viral load detected with PCR. He required multiple top ups &amp; exchange transfusions. Ultimately, Intravenous Immunoglobulins (IVIG) were administered to control his overwhelming viral infection, and he responded successfully. Another interesting case is a 5‐year‐old boy with SCD and G6PD deficiency. He presented with increasing anemia, jaundice and hemoglobinuria. All lab parameters were consistent with acute intravascular hemolysis, combined with suboptimal marrow response evidenced by reticulocytopenia. Coombs test and flow cytometry for Paroxysmal Nocutrnal Hemoglobinuria were negative. Parvovirus B19 PCR was positive in a significantly high copy number. The boy was diagnosed as a case of acute intravascular hemolytic anemia due to G6PD deficiency triggered by concomitant Parvovirus B19 infection which explains the reticulocytopenia. The patient required transfusion three times, then discharged uneventfully.Summary/Conclusion:Parvovirus B19 infection is common in children with SCD. Clinical presentations are not confined to classical aplastic crisis. High index of suspicion is needed to identify Parvovirus specially in cases presented with acute splenic sequestration. We recommend screening for Parvovirus in all cases presented with acute splenic seqestration coupled with suboptimal reticulocyte reponse. In severe refractory cases of Parvo infection, IVIG might be used as a salvage therapy.

S100A8 acts as an autocrine priming signal for heme-induced human Mϕ pro-inflammatory responses in hemolytic inflammation.

Intravascular hemolysis, in addition to reducing red cell counts, incurs extensive vascular inflammation and oxidative stress. One product of hemolysis, heme, is a potent danger associated molecular pattern (DAMP), activating leukocytes and inducing cytokine expression and processing, among other pro-inflammatory effects. We explored pathways by which heme-induced inflammation may be amplified under sterile conditions. Incubation of human Mϕs, differentiated from CD14+ cells, with heme induced time- and concentration-dependent gene and protein expression of S100A8, a myeloid cell-derived alarmin. Human Mϕ stimulation with recombinant S100A8, in turn, induced robust pro-IL-1β expression that was dependent upon NF-κB activation, gene transcription, and partially dependent upon TLR4-mediated signaling. Moreover, heme itself stimulated significant Mϕ pro-IL-1β gene and protein expression via an S100A8-mediated mechanism and greatly amplified S100A8-driven NLRP3 inflammasome-mediated IL-1β secretion. In vivo, induction of acute intravascular hemolysis in mice induced a rapid elevation of plasma S100A8 that could be abolished by hemopexin, a heme scavenger. Finally, plasma S100A8 levels were found to be significantly elevated in patients with the inherited hemolytic anemia, sickle cell anemia, when compared with levels in healthy individuals. In conclusion, we demonstrate that hemolytic processes are associated with S100A8 generation and that some of the inflammatory effects of heme may be amplified by autocrine S100A8 production. Findings suggest a mechanism by which hemolytic inflammation could be propagated via leukocyte priming by endogenous proteins, even in sterile inflammatory environments such as those that occur in the hemolytic diseases. S100A8 may represent a therapeutic target for reducing inflammation in hemolytic disorders.

Acute intravascular hemolysis due to naphthalene toxicity: a case report

BackgroundNaphthalene (mothball) is a commonly used deodorizer in the Indian subcontinent, including Sri Lanka. Though it is freely available around this country, poisoning has never been reported in the literature. Ingestion, either accidental or by deliberate self-harm, can occur due to its abundance as well as its candy-resembling appearance.Case PresentationA 33-year-old Sri Lankan woman presented to us 2 days after the self-ingestion of 15 naphthalene balls. She had features of intravascular hemolysis without features of pigment nephropathy or methemoglobinemia. She was symptomatically managed with blood transfusion and adequate hydration.ConclusionNaphthalene ingestion can lead to severe intravascular hemolysis as well as methemoglobinemia. The resultant pigment nephropathy may also lead to acute kidney injury.

P. falciparum Malaria induced Renal impairment

Introduction: The involvement of the kidney in falciparum malaria has been known for decades. In 1944, Spitz observed acute renal failure due to falciparum infection in soldiers during World War II. This observation was later supported by other workers who detected oliguria developing in patients with black water fever. The initial clinical pattern is that of reversible renal dysfunction or pre-renal azotemia, which rapidly progresses to acute tubular necrosis if treatment is not started early. Patients with malaria induced renal failure are hypercatabolic with blood urea and serum creatinine levels rising rapidly.Oliguric as well non-oliguric renal failure are observed and duration of oliguric renal failure ranges from a few days to several weeks depending on the severity of renal dysfunction. Acute renal failure in falciparum malaria is usually associated either with acute intravascular haemolysis or heavy parasitemia. Acute renal failure in falciparum malaria is also observed in patients with severe intravascular haemolysis resulting in haemoglobinuria. It may be induced by malarial fever or by anti-malarial drugs in a patient with or without G6-PD deficiency. Materials and Methods: This is a hospital based cross sectional study carried out in a total of 50 cases of acute renal failure who were selected from diagnosed patients of P. falciparum malaria. Cases were confirmed either by P. falciparum antigen test and/or peripheral blood smear test(both thick and thin smear).Malarial ARF (MARF) is diagnosed when serum creatinine level &gt; 3 mg/dl, and/or urine output &lt; 400 ml/24hrs despite adequate rehydration. Result: Out of 174 cases of falciparum malaria 50 patients (28.7%) had acute renal failure in falciparum malaria. 36 (72%) cases were males and 14 (28%) were females, indicating a much higher incidence in males. Approximately 78% of the cases in the present study were below the age of 40 years. The youngest was 15 years old and the oldest was 61 years old (Mean age – 32 ± 11.6 years). All were febrile (100%) and a majority had oliguria or anuria (72%); jaundice was detected in 30 (60%) patients on presentation. Hepatomegaly &amp; Splenomegaly were found in 76% &amp; 66% of the cases respectively. Out of the total 50 cases of malaria induced ARF, 14 cases (28%) had pre-renal ARF while in the majority, 72% the clinical course was that of ATN. The pathogenesis of ATN in the 36 cases was found to be heavy parasitaemia in 40% of the cases, IV hemolysis with haemoglobinuria in 3 (6%) of cases; and cholestatic jaundice in 26% of falciparum patients. Examination of the urinary sediments revealed that albumin was present in urine in 40 cases (80%). Majority of the patients had significant rise in blood urea level with a mean value of 177 mg. S. creatinine levels ranged between 3.2 - 13.6 mg with a mean value of 7.83 mg. The mean creatinine clearance rate was 11.71 ml/min. The overall mortality rate was 26%. Conclusion: AKI is common in Falciparum malaria. The pathogenesis of AKI is largely unknown but may be related to the erythrocyte sequestration and agglutination within the renal microcirculation interfering with flow and metabolism. Clinically and pathologically, this syndrome manifests as Pre-renal azotemia and acute tubular necrosis. Acute renal failure may occur simultaneously with other vital-organ dysfunction (in which case the mortality risk is high) or may progress as other disease manifestations resolve. Early dialysis or hemofiltration considerably enhances the likelihood of a patient’s survival, particularly in acute hypercatabolic renal failure. Severity of oliguria and presence of one or more associated complications like pulmonary oedema, acidosis, and altered sensorium have considerable influence on the outcome of the patients.

Kerosene, Camphor, and Naphthalene Poisoning in Children.

ABSTRACTKerosene poisoning is one of the most common accidental poisoning in children in developing countries due common use of kerosene in house-hold and unsafe storage practices. Aspiration pneumonitis is the most common manifestation of kerosene ingestion due to its low viscosity, high volatility, and low surface tension. The treatment of aspiration pneumonitis due to kerosene poisoning is symptomatic including oxygen support, respiratory monitoring, and careful monitoring of fluid balance. Children with severe respiratory distress and hypoxemia unresponsive to supplemental oxygen and/or severe central nervous system involvement require early intubation and mechanical ventilation. Transfer to the pediatric intensive care unit (PICU) is required at this stage. Emesis, gastric lavage, and administration of activated charcoal are contraindicated due to risk of aspiration. There is no clear benefit of using corticosteroids or prophylactic antibiotics. Asymptomatic children should be kept under observation for atleast 6 hours after exposure. The mortality rate is low and death occurs due to pneumonitis. Camphor is used in house-hold items including vaporized or topical cold preparations, liniments, moth repellents, for performing rituals in religious ceremonies, and in antimicrobial preparations. Camphor poisoning is not very common in childhood. Even small doses of camphor can cause serious toxicity and is potentially fatal. The onset of action is very rapid (5–15 minutes). The common manifestations are confusion, restlessness, delirium, and hallucinations, muscle twitching, myoclonus, ataxia, hyperreflexia, fasciculations, and seizures. Seizures are common and serious complication in camphor toxicity. The treatment is supportive including decontamination, gastric lavage, activated charcoal, and seizure control. Naphthalene is a major constituent of mothballs which are commonly used in household to protect clothes from moths. Though the poisoning with naphthalene is uncommon in children, most of the cases with naphthalene poisoning occur in developing countries where mothballs are still commonly used. The manifestations of naphthalene toxicity are predominantly due to acute intravascular hemolysis leading to anemia, hemoglobinuria, methemoglobinemia, and acute kidney injury (AKI). The treatment of naphthalene toxicity is supportive in form of transfusion of the packed red blood cells, monitoring of fluid and electrolyte balance, administration of alkalis in presence of hemoglobinuria, and renal replacement therapy. Prevention is better than cure. The strategies should be adopted to prevent children being exposed to these toxic compounds in the house-hold. Safe storage of toxic compounds away from the reach of children, avoiding storing kerosene in cold drink and beverage bottles, community education, provision of electricity in rural areas, safe cooking practices, and parental supervision are important interventions to prevent accidental poisoning among children.How to cite this articleKumar S, Kavitha TK, Angurana SK. Kerosene, Camphor, and Naphthalene Poisoning in Children. Indian J Crit Care Med 2019;23(Suppl 4):S278–S281.

Acute Hemolysis Induces Pro-Angiogenic Molecule Production and Neovascularization In Vivo

Background: The intravascular hemolysis associated with hemolytic disorders, such as sickle cell anemia, results in the release of cell-free hemoglobin (Hb) and heme in the circulation, in turn, inducing inflammatory processes, vascular damage and endothelial activation. Angiogenesis, or the formation of new blood vessels, involves the proliferation, migration, and reorganization of endothelial cells in response to diverse physiological or pathological stimuli. Although angiogenesis is important for tissue growth and regeneration, uncontrolled angiogenesis can result in the accumulation of inflammatory cells, together with fibrosis and ischemia, and could play a role in some of the complications of hemolytic disorders. Aim: The aim of this study was to characterize angiogenic and inflammatory responses to the hemolytic process using an experimental in vivo model of acute hemolysis. Methods: C57BL/6J male mice were submitted, or not, to an osmotic hemolytic stimulus by intravascular injection of 150μL of sterile water (HEM group) or saline (CON group). After 1, 24 and 120 h, blood was collected by cardiac puncture for cell counts and plasma Hb and total heme quantification (colorimetric assays). Hemopexin, haptoglobin, inflammatory cytokines (Interleukin [IL]-6, IL-1β and IL-10) and angiogenic factors (Angiopoietin-2, Fibroblast growth factor [FGF]-basic, Platelet-derived growth factor [PDGF]-AA, PDGF-BB, Trombospondin-4, Vascular endothelial growth factor [VEGF], VEGFR2) were quantified in plasma by immunoassay. To evaluate in vivo neovascularization, a Matrigel®/ heparin mixture was injected subcutaneously into the dorsal region of the mice, two days before the administration of the hemolytic stimulus. After five more days, the Matrigel® plugs were removed, photographed and neovascularization quantified by colorimetric measurement of Hb in the plug. Results: At 1 h after the acute hemolytic stimulus, significant increases were observed in plasma Hb and heme (0.1±0.02 vs 0.2±0.03 g/L Hb, p<0.001; 32.9±1.9 vs 50.04±4.6 µM heme, p<0.01, for CON and HEM [1h], respect., n=5), indicative of the induction of hemolysis. Haptoglobin levels were almost completely depleted at 1 h after hemolysis, but recovered and were even higher at 24 h (14.2±2.9 vs 1.1±0.3 and 34.6±2.1 ng/mL for CON, HEM [1h] and HEM [24h], respect., p<0.01, n=5), before normalizing at 120 h. In contrast, circulating levels of hemopexin were not altered at any time post hemolysis (data not shown, p>0.05). Hemolysis also elevated the white blood cell count (2.2±0.2 vs 3.5±0.3 103/µL for CON and HEM [1h], respect., p<0.05, n=5) and plasma IL-10 (4.8±0.6 vs 12.4±1.7 pg/mL for CON and HEM [1h] respect., p<0.001, n=10 and n=5) within 1h, suggesting that systemic inflammation accompanied this hemolysis. The red blood cell count did not change in the HEM group at any of the time points, nor did plasma IL-1β or IL-6 levels (p>0.05). A balance of angiogenic mediators, including growth factors and inflammatory cytokines, regulates angiogenesis; at 1 h after hemolysis, plasma levels of angiopoietin-2 were decreased (2.75±0.1 vs 2.1±0.15 ng/mL for CON and HEM [1h], respect., p<0.05, n=5), while pro-angiogenic VEFG and trombospondin-4 were significantly increased (163.1±8.9 vs 233.3±15.8 pg/mL and 148.6±4.1 vs 169.4±7.1 ng/mL for CON and HEM [1h], respect., p<0.05, n=5), by 24 h levels of angiogenic markers were normalized. In association with the alterations in the molecular angiogenic profile of mice after hemolysis, the formation of new blood vessels in dorsal Matrigel® plugs was significantly elevated during the 5 days following the hemolytic stimulus, as quantified by plug Hb content (2.0±0.3 vs 3.0±0.04 µg/mL for CON and HEM mice, respect., p<0.05, n=10, 11). Conclusions: Acute intravascular hemolysis was associated with rapid alterations in circulating angiogenic and inflammatory markers in mice. In association with this pro-angiogenic profile, in vivo neovascularization was accelerated in animals following hemolysis. These data suggest that hemolysis may be a significant stimulus for angiogenic processes, which in turn may contribute to some of the clinical complications of hemolytic diseases, including pulmonary hypertension, stroke and leg ulcers. Furthermore, the angiogenic process may represent a target for the development of therapeutic strategies in disorders characterized by hemolysis. DisclosuresNo relevant conflicts of interest to declare.