Influence of lithium and fluoride on degranulation from human neutrophils in vitro

Hemodialysis Treatment for Patients with Lithium Poisoning

BACKGROUND

Hemodialysis is often recommended to treat severe lithium poisoning. Nevertheless, the application rate of hemodialysis in patients with lithium poisoning is varied across different groups and the effect of hemodialysis is still undetermined. Therefore, this study aimed to analyze the hemodialysis rate of patients with lithium poisoning and to explore the clinical features of lithium-poisoned-patients treated or untreated with hemodialysis.

METHODS

Between 2001 and 2019, 36 patients treated at the Chang Gung Memorial Hospital for the management of lithium poisoning were stratified according to whether they were treated with hemodialysis (n = 7) or not (n = 29).

RESULTS

The patients were aged 50.7 ± 18.1 years. The poisoning patterns were acute on chronic (61.1%), chronic (25.0%) and acute (13.9%). The precipitating factors of dehydration and infection were noted in 36.1% and 25.0% of patients, respectively. Bipolar disorder (72.2%), depressive disorder (27.8%) and psychotic disorder (11.1%) were the top three psychiatric comorbidities. The hemodialysis group not only had a lower Glasgow Coma Scale (GCS) score (p = 0.001) but also had a higher respiratory failure rate (p = 0.033), aspiration pneumonia rate (p = 0.033) and acute kidney injury network (AKIN) score (p = 0.002) than the non-hemodialysis group. Although none of the patients died of lithium poisoning, the hemodialysis group required more endotracheal intubation (p = 0.033), more intensive care unit admission (p = 0.033) and longer hospitalization (p = 0.007) than the non-hemodialysis group.

CONCLUSION

The analytical results revealed zero mortality rate and low hemodialysis rate (1.9%). Compared with patients without hemodialysis, patients receiving hemodialysis suffered severer lithium-associated complications and needed a more intensive care unit admission and longer hospital stay.

Characterization of soluble folate receptors (folate binding proteins) in humans. Biological roles and clinical potentials in infection and malignancy

This review surveys soluble Folate Receptors (FOLRs) in humans. FOLR1 and FOLR2 are equipped with cellular glycosylphosphatidylinositol (GPI) anchors. FOLR1 is secreted from epithelia with or without a micelle-encapsulated GPI-anchor into milk and other body fluids/secretions, e.g. semen where its interaction with spermatozoa indicates a role in male fertility. FOLR1 and FOLR2 serve as serum biomarkers of various diseases. FOLR3 possesses no GPI-anchor and originates from secretory granules of neutrophil granulocytes; its concentration in serum correlates to the FOLR3 content in leukocytes and rises with increased leukocyte counts (infection, malignancy and pregnancy). FOLR3 exerts anti-microbial and anti-tumor effects by depriving bacteria and tumor cells of natural folates. Megalin receptors mediate reabsorption of ultrafiltered folate-bound FOLR into cells of proximal kidney tubules and of folate-bound FOLR uptake in growing embryos. Megalin receptors overexpressed in malignant tumors could be suitable therapeutic targets for folate-conjugated cytotoxic agents utilizing soluble FOLRs as vectors.

A rare case of acute respiratory distress syndrome secondary to acute lithium intoxication

Lithium carbonate is a widely administered antimanic drug used for the treatment of bipolar disorder, schizoaffective disorder, and depression. Despite the established clinical efficacy of lithium, its usage must be approached with caution due to its narrow therapeutic index. Lithium poisoning results in multisystem toxicity, and characteristic clinical manifestations are directly correlated to serum lithium concentration. We describe a rather rare but fatal side effect of lithium: acute respiratory distress syndrome (ARDS) in a 46-year-old female on lithium for the treatment of bipolar disease. She was referred for generalized weakness, found in hemodynamic compromise, and had laboratory data significant for a lithium level of 3.3 mmole/L, needing emergent hemodialysis. Subsequently, she developed hypoxic respiratory failure requiring intubation. Her chest x-rays showed new bilateral pulmonary edema, the computed tomography scan showed extensive alveolar consolidation and V/Q scan of low probability for pulmonary embolism. She underwent 3 dialysis sessions and supportive care and was able to be extubated in 5 days. To our knowledge, 4 cases of ARDS after the onset of lithium toxicity have been documented. All patients presented with altered mental status at serum lithium levels ranging from 3.8 to 4.9 mmole/L and cardiogenic etiologies in addition to other likely causes of ARDS were ruled out in each case. The patients were treated with saline hydration (50%) or hemodialysis (50%), indicating that hemodialysis may be a permissive factor in lithium-associated ARDS development rather than a required component. Taken together, we believe that lithium is a likely culprit in the initiation of ARDS and propose the addition of ARDS to the family of clinical manifestations of severe lithium toxicity.

alpha Isoforms of soluble and membrane-linked folate-binding protein in human blood

The high-affinity FBP/FR (folate-binding protein/folate receptor) is expressed in three isoforms. FRalpha and FRbeta are attached to cell membranes by hydrophobic GPI (glycosylphosphatidylinositol) anchors, whereas FBPgamma is a secretory protein. Mature neutrophil granulocytes contain a non-functional FRbeta on the surface, and, in addition, nanomolar concentrations of a secretory functional FBP (29 kDa) can be present in the secondary granules. A statistically significant correlation between the concentrations of functional FBP, probably a gamma isoform, in granulocytes and serum supported the hypothesis that serum FBP (29 kDa) mainly originates from neutrophils. The presence of FBP/FRalpha isoforms were established for the first time in human blood using antibodies specifically directed against human milk FBPalpha. The alpha isoforms identified on erythrocyte membranes, and in granulocytes and serum, only constituted an almost undetectable fraction of the functional FBP. The FBPalpha in neutrophil granulocytes was identified as a cytoplasmic component by indirect immunofluorescence. Gel filtration of serum revealed a peak of FBPalpha (>120 kDa), which could represent receptor fragments from decomposed erythrocytes and granulocytes. The soluble FBPs may exert bacteriostatic effects and protect folates in plasma from biological degradation, whereas FRs on the surface of blood cells could be involved in intracellular folate uptake or serve as signal proteins. The latter receptors have also been used for therapeutic targeting in malignancy.

Lithium

The mode of action of the cation lithium is not well known. It is at present used as a topical drug in dermatology. Lithium inhibits many enzymes: Na/K ATPase, adenylcyclase, enzymes of the prostaglandines E1 synthesis, inositol-1-phosphatase. It is active on neutrophils et T lymphocytes, explaining in part its anti-inflammatory activity. It has a dose-dependent action on levures. It has possibly a direct inhibitory activity on DNA synthesis of herpes viruses. Lithium has a good local safety. Percutaneous penetration is weak and plasma concentrations are very much lower than that observed after oral intake. Lithium has been studied in seborrhoeic dermatitis. Its efficacy was primarily observed in psychotic patients. An assay with oral lithium did not confirmed the first observations. Topical lithium was found more efficient. Topical lithium succinate associated with zinc sulfate and lithium gluconate had a greater efficacy than placebo. Comparison with topical ketoconazole showed a non inferiority of lithium gluconate. Oral lithium also showed a reduction of symptoms' duration of herpes simplex. Cutaneous side-effects of oral lithium are frequent and numerous. Some of them may be explained by a lithium pharmacological cell activity (such as psoriasis). Teratogenicity is observed in mice and rats. Drug interactions are not expected after topical application. Irritants side effects are mainly observed after topical application; they are moderate and transitory. Lithium gluconate treatment of seborrhoeic dermatitis is a bid application during at least 8 weeks. It may be used in renal insufficiency. It is not recommended in the first trimester of pregnancy.

Vitamin B12 and folate levels and lithium administration in patients with affective disorders

BACKGROUND

It is unclear whether there is a relationship between lithium administration and vitamin B12 metabolism.

METHODS

We compared serum B12, serum folate, and red blood cell folate concentrations in patients receiving and not receiving lithium at two Mood Disorders Clinics. As the two centers differed in vitamin assay methods, data were first analyzed separately and then combined. To rule out an in vitro effect of lithium on the assays, we also added varying amounts of lithium to lithium-free blood samples and measured vitamin concentrations.

RESULTS

Mean serum B12 concentrations were approximately 20% lower in the lithium than in the nonlithium group at each center. This difference was statistically significant for each center and on combination (two-tailed p = .017, .021, and .0009). The parametric effect size for each center and the combined weighted mean effect size were moderate in magnitude (.605, .523, and .565). There was a nonsignificant trend toward an increased prevalence of assay-defined B12 deficiency in the lithium group at one center only, with no cases in either group at the other center and a nonsignificant combined relative risk.

CONCLUSIONS

Our data may represent a lithium-associated decrease in serum B12 concentration. The clinical significance of these findings is not yet clear.

Lithium-induced follicular hyperkeratosis

A wide range of cutaneous reactions have been described in association with lithium therapy. Follicular eruptions have been noted briefly, but are not well documented in the dermatological literature. We report a 68-year-old man who developed a florid erythematous follicular eruption on the extensor surfaces of the limbs, with macular truncal erythema 6 months after commencing lithium therapy. His blood lithium levels were within the therapeutic range and there was no clinical evidence of lithium toxicity. Histology of lesional skin showed perifollicular inflammation and follicular plugging. The eruption improved on drug withdrawal. The cutaneous reactions to lithium and possible pathogenic mechanisms are discussed.

Exacerbation of psoriasis during lithium treatment

Exacerbation of psoriasis was observed in a 28-year-old patient following the addition of lithium carbonate to a treatment regimen of carbamazepine and other drugs for manic-depressive psychosis. The biopsied lesion histologically showed a typical psoriasiform tissue reaction and immunohistochemically, remarkable infiltration of activated helper T cells. Immunologic reaction to lithium in a patch test and a lymphocyte proliferation test could not be demonstrated. The mechanisms of lithium action and their relations to the exacerbation of psoriasis were reviewed. In this patient, although we could not define which effect of lithium was most important, it seemed that an increased blood lithium level combined with simultaneous carbamazepine administration enhanced the triggering effect of lithium and caused the exacerbation of psoriasis.

Enhanced chemiluminescence production by phagocytosing neutrophils in psoriasis

Using serum-coated zymosan, the generation of reactive oxidants by measurement of chemiluminescence was shown to be significantly enhanced in isolated peripheral psoriatic neutrophils compared to normal controls. This response was observed irrespective of whether zymosan was opsonized with fresh autologous or normal AB serum. However, this increased activity was reduced with zymosan was opsonized with serum that was preheated at 56 degrees C for 30 min. There was no statistical correlation of chemiluminescence activity with degranulation of beta-glucuronidase in either normal or psoriatic subjects. In addition, chemiluminescence produced by normal cells was significantly increased when zymosan was opsonized with psoriatic serum. The plasma membrane-bound enzyme, NAD(P)H oxidase, which produces superoxide in response to phagocytic stimulation, was significantly increased in psoriatic neutrophils compared to normal controls. These data add further evidence for activated neutrophils in psoriasis.

Effect of lithium therapy on inflammatory response

Chemiluminescence produced by normal cells was reduced in response to zymosan which was opsonized with serum from patients on prophylactic lithium therapy, compared to control serum from normal subjects (68 +/- 3.1 vs. 93 +/- 3.4 mV/5 X 10(5) cells). Preincubation of normal cells with serum from patients also resulted in reduced chemiluminescence activity when the cells were stimulated with autologous serum-coated zymosan (47 +/- 4.5 vs. 64 +/- 6.3 mV/5 X 10(5) cells). Spontaneous complement conversion was increased in the serum of patients on lithium therapy (46.3 +/- 3.8 vs. 25.3 +/- 2.5% conversion). These studies demonstrated that lithium, at safe therapeutic levels (0.4-0.9 mmol/liter), significantly altered complement conversion and had a marked affect on chemiluminescence activity by normal cells.

Li+-induced release of the folate binding protein from human granulocytes

Release of folate binding protein from human leucocytes suspended in isotonic NaCl was studied in experiments where folate binding activity of the suspending medium was determined by equilibrium dialysis (pH 7.4, 37 degrees C) against 3H-folate. Release from leucocytes containing particularly high concentrations of folate binding protein was significantly increased in the presence of 70 mmol/l Li+. The stimulated release was apparently not an osmotic phenomenon since no effect was observed with isomolar Na+/K+. The released protein resembled the folate binding protein in leucocyte lysate as to characteristics of radioligand binding, ionic properties and molecular size. Hence no transformation of the protein seemed to occur during Li+-induced release.

Enhanced release of inflammatory mediators from lithium-stimulated neutrophils in psoriasis

We have used lithium salts to stimulate degranulation in order to assess neutrophil activity in psoriasis. Evidence is presented for significant enhancement of degranulation of beta-glucuronidase (primary granules) and vitamin B12-binding protein (secondary granules) from lithium-stimulated neutrophils in psoriatic whole blood. Basal levels of granule markers showed no significant difference between normal and psoriatic neutrophils. On the other hand, enzymes associated with neutrophil function (myeloperoxidase and catalase) were found to be markedly increased in resting psoriatic neutrophils.