Intermittent hemophagocytic lymphohistiocytosis is a regular feature of lysinuric protein intolerance.
ABSTRACT We describe 4 cases of lysinuric protein intolerance, which all fulfilled the diagnostic criteria for hemophagocytic lymphohistiocytosis. Mature histiocytes and neutrophil precursors participated in hemophagocytosis in the bone marrow. Moreover, serum levels of ferritin and lactate dehydrogenase were elevated, hypercytokinemia was present, and soluble interleukin-2 receptor levels were increased up to 18.6-fold. The diagnosis of lysinuric protein intolerance should therefore be considered in any patient presenting with hemophagocytic lymphohistiocytosis.
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ABSTRACT: Transcobalamin II (TC II) deficiency is a rare disorder of cobalamin (CBL, vitamin B12) metabolism that occurs due to mutations in transcobalamin gene (TCN2). Hemophagocytic lymphohistiocytosis (HLH) in contrast is a syndrome characterized by uncontrolled immune response with hyperinflammation. A 2-month-old male baby was admitted with complaints of fever, cough, diarrhea, and respiratory distress. The parents were first cousins. The baby exhibited five of the eight diagnostic criteria for HLH-2004 and was diagnosed as HLH. A second bone marrow aspiration demonstrated megaloblastic changes in the erythroid series. The patient's vitamin B12 level was normal; however, hyperhomocysteinemia was present. A genetic deficiency of TC II was suspected. The patient and his parents were tested for TCN2 mutation. He had a homozygote mutation that was not included in Human 'Gene Mutation Database Cardiff'. The patient was treated with intramuscular vitamin B12, which was followed by improvement in both clinical and laboratory findings. He was 12 months old at the time of this report, with normal physical and neuromotor development. In this case presenting with the clinical and laboratory findings of HLH, TC II deficiency was diagnosed. A new mutation was found that was not reported before. Potential causative mechanisms of HLH induced by defects of cobalamin synthesis merit further investigation.International journal of hematology 02/2014; · 1.17 Impact Factor
Article: Hemophagocytic syndromes - An update[Show abstract] [Hide abstract]
ABSTRACT: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome and not an independent disease. HLH represents the extreme end of a severe uncontrolled hyperinflammatory reaction that can occur in many underlying conditions. Genetic forms of HLH s are due to defects in transport, processing and function of cytotoxic granules in natural killer cells and cytotoxic T lymphocytes, and are not restricted to manifestation in childhood. Acquired forms of HLH are encountered in infections, autoinflammatory and autoimmune diseases, malignancies, acquired immune deficiency. Functional tests allow for differentiation between genetic and acquired HLH. Treatment aims at suppressing hypercytokinemia and eliminating activated and infected cells. It includes immunomodulatory and immunosuppressive agents, cytostatics, T-cell and cytokine antibodies. In genetic HLH cure can only be achieved with hematopoietic stem cell transplantation. Reduced-intensity conditioning regimens have considerably improved survival.Blood reviews 01/2014; · 7.19 Impact Factor
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ABSTRACT: The lysosomal acid lipase (LAL) is the enzyme responsible of the hydrolysis of cholesteryl esters and triglycerides within endo-lysosomes. Loss of enzyme activity leads to accumulation of cholesteryl esters and triglycerides in the lysosome of most tissues. The complete deficiency of LAL is responsible of Wolman disease (WD), a severe systemic disease manifesting in the first days of life with vomiting, diarrhea, failure to thrive, hepatosplenomegaly, jaundice, anemia, and thrombocytopenia. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition which may be genetically determined or secondary to infections, malignancies, immune deficiencies, and rheumatologic disorders. So far, some inborn errors of metabolism have been associated with HLH (e.g., lysinuric protein intolerance, Gaucher's disease), and it has been anecdotally described in three WD patients, without any specific pathogenetic hypothesis. Here, we report on a WD patient, showing clear clinical, biochemical, and histological features indicative of HLH. We discuss the pathophysiological role of cholesteryl ester-induced inflammasome activation in macrophages, leading to a secondary HLH. Conclusion: This case indicates that WD can cause secondary HLH and suggests that a careful metabolic workup should be performed when facing to a pediatric patient with HLH.European Journal of Pediatrics 05/2014; · 1.91 Impact Factor