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PubMed2001

Macrophage effector mechanisms in melanoma in an experimental study.

BACKGROUND: The tumor-bearing state is known to induce immune dysfunction that contributes to increased infectious complications and tumor progression. However, the mechanisms underlying this immunosuppression remain unclear. HYPOTHESIS: Macrophage (MO) dysfunction may play a role in tumor-induced immunosuppression. DESIGN AND MAIN OUTCOME MEASURES: Using a murine model, this study investigated the effects of melanoma growth on peritoneal macrophage effector molecule and prostaglandin production, MO-mediated cytotoxicity, and candidacidal mechanisms. Female C57BL/6 mice were inoculated with 106 B16 melanoma cells or a salt solution subcutaneously. Mice were euthanized 3 weeks later and peritoneal MOs were harvested and assayed for nitric oxide, superoxide anion, tumor necrosis factor alpha, and prostaglandin E(2)production. Macrophage-mediated cytotoxicity against B16 melanoma targets and MO candidacidal mechanisms were also measured. RESULTS: Macrophage production of nitric oxide, superoxide anion, and tumor necrosis factor alpha were significantly decreased, while prostaglandin E(2)production was increased in MOs from melanoma-bearing mice. Concomitantly, MO-mediated cytotoxicity and candidacidal mechanisms were significantly impaired. CONCLUSIONS: Melanoma growth leads to decreased MO effector molecule production, increased prostaglandin E(2)production, and impaired MO cytotoxic and candidacidal mechanisms. These results may help explain the observed increased infectious complications in the tumor-bearing host. Strategies aimed at restoring MO function may have therapeutic potential.

Animals↗
PubMed1992

Modulation of macrophage hyperactivity improves survival in a burn-sepsis model.

Macrophage hyperactivity with increased production of tumor necrosis factor, interleukin 6, interleukin 1, and prostaglandins has been demonstrated in the injured patient, but the effect of this on the clinical outcome is unclear. We studied the effect of combination interleukin 1 beta and indomethacin sodium therapy on macrophage hyperactivity and survival after sepsis in a murine burn model. Macrophage interleukin 1, interleukin 6, and tumor necrosis factor alpha production were all significantly increased 10 days after thermal injury. Treatment with recombinant human interleukin 1 beta in combination with indomethacin significantly reduced this overproduction of cytokines to normal levels, and this was associated with an improvement in survival after septic challenge (52% survival in interleukin 1 beta-indomethacin-treated group compared with 22% in burned vehicle control mice). Burned mice that received either interleukin 1 beta or indomethacin alone demonstrated tumor necrosis factor and interleukin 6 production and survival intermediate between the interleukin 1 beta-indomethacin-treated group and the vehicle control group. Control of macrophage hyperactivity is associated with improved survival from subsequent sepsis and offers a potential new strategy for the treatment of immune dysfunction in thermally injured patients.

Animals↗
PubMed2005

Childhood vaccination and nontargeted infectious disease hospitalization.

CONTEXT: It has been hypothesized that multiple-antigen vaccines, such as measles-mumps-rubella vaccine, or aggregated vaccine exposure could lead to immune dysfunction, resulting in nontargeted infectious diseases as a result of an "overload" mechanism. OBJECTIVE: To evaluate the relationship between routinely administered childhood vaccines (Haemophilus influenzae type b; diphtheria-tetanus-inactivated poliovirus; diphtheria-tetanus-acellular pertussis-inactivated poliovirus; whole-cell pertussis; measles-mumps-rubella; oral poliovirus) and hospitalization for nontargeted infectious diseases. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort comprising all children born in Denmark from 1990 through 2001 (N = 805 206). Longitudinal information was collected on type and number of vaccine doses received and hospitalization with infectious diseases, specifically acute upper respiratory tract infection, viral and bacterial pneumonia, septicemia, viral central nervous system infection, bacterial meningitis, and diarrhea. MAIN OUTCOME MEASURES: Rate ratios for each type of infectious disease according to vaccination status. RESULTS: During 2,900,463 person-years of follow-up, 84,317 cases of infectious disease hospitalization were identified. Out of 42 possible associations (6 vaccines and 7 infectious disease categories), the only adverse association was for Haemophilus influenzae type b vaccine and acute upper respiratory tract infection (rate ratio, 1.05; 95% confidence interval, 1.01-1.08 comparing vaccinated participants with unvaccinated participants). This one adverse association of 42 possible outcomes was within the limits of what would be expected by chance alone and the effect was not temporal or dose-response. When considering aggregated vaccine exposure, we found no adverse associations between an increasing number of vaccinations and infectious diseases. CONCLUSION: These results do not support the hypotheses that multiple-antigen vaccines or aggregated vaccine exposure increase the risk of nontargeted infectious disease hospitalization.

Child↗
PubMed2000

Effects of hypoxia on granulocytic-monocytic progenitors in rats. Role of bone marrow stroma.

Hemorrhagic shock leads to hypoxia and is associated with bone marrow (BM) failure. Hemorrhagic shock is also a predisposing factor in immune dysregulation. Since the BM is the major organ of immune cells in the adult, its failure following hemorrhagic shock may explain the increased susceptibility to infection. The in vitro evidence indicates that hypoxia mediates altered functions in BM stroma. Since similar hematopoietic alterations are reported in hypoxia and hemorrhagic shock, hypoxia alone could be a representative model to study BM responses during hemorrhagic shock. In this study, we use an animal model to dissect the hematopoietic effects of hypoxia. We subjected rats to hypoxia, and at days 1 and 5 post-hypoxia we determined the numbers of granulocytic-monocytic progenitors (CFU-GM) in the BM. We found significant increase (P < 0.05) in CFU-GM at day 1 and a downward trend by day 5. Enhanced BM cellularity could not explain the increase in CFU-GM by day 1. BM stromal cells mediated most of the stimulatory effects by hypoxia. CFU-GM was inversely proportional to bioactive TGF-beta and directly proportional to IL-1. Compared to normoxic rats, IL-6 production was suppressed in BM cells from hypoxic rats. The results show that hypoxia alone initiate a stimulatory response in CFU-GM progenitors. These effects are at least partially mediated through the BM stroma. In the absence of a second insult, CFU-GM reverts to baseline. The data also suggest that hypoxia mediates complex responses that include cytokine production. These results add to the current understanding of hematopoietic responses by hypoxia and adds to the mechanisms of immune dysfunctions following hemorrhagic shock.

Animals↗
PubMed1998

Langerhans cell histiocytosis in children: does soluble interleukin-2-receptor correlate with both disease extent and activity?

BACKGROUND: Langerhans cell histiocytosis (LCH) is characterized by monoclonal proliferation of activated Langerhans cells. Neither etiology nor pathomechanism of this disorder is presently known. However, despite monoclonality LCH might represent a reactive clonal disorder induced by immune dysfunction rather than a malignant process. To investigate a putative cytokine dysregulation in the pathogenesis of this disorder and searching for parameters of both disease activity and prognosis, serum concentrations of proinflammatory and T-cell derived cytokines were evaluated in LCH patients. MATERIALS AND METHODS: Serum levels of IL-1 beta, IL-2, sIL-2R and TNF-alpha were determined by ELISA in seven children with different types of LCH: Three children (aged 6, 10 and 14 years, respectively) with single system/single bone disease; one child (11 years) with recurrent single system/multiple bone disease and three children (1, 2 and 2 years, respectively) with multisystem disease. RESULTS: sIL-2R was elevated at diagnosis in seven children as compared to healthy adults (mean +/- SEM: 5,256 +/- 3,751 U/ml vs. 73 +/- 5.5 U/ml; P < 0.005) or healthy children (mean +/- SEM: 10,195 +/- 2,798 pg/ml vs. 2,638 +/- 156 pg/ml; P < 0.01). A positive correlation between serum levels of sIL-2R and extent of the disease could be observed. During remission, sIL-2R levels declined. IL-1 beta, IL-2, and TNF-alpha remained within the normal range during the study period. CONCLUSIONS: Elevated sIL-2R levels seem to correlate positively with both extent and activity of LCH, thus indicating a pathological T-cell activation as a pathogenetic factor. sIL-2R level is a promising parameter to monitor disease activity in LCH and may also be of prognostic relevance.

Adolescent↗
PubMed2000

Occurrence of primary cancers in association with multiple myeloma and Kaposi's sarcoma in the United States, 1973-1995.

The causes of multiple myeloma (MM) are obscure, but a laboratory association was recently reported between MM and human herpesvirus 8 (HHV-8), the probable etiologic agent of Kaposi's sarcoma (KS). Although there has been some additional laboratory corroboration, most laboratory studies have found no association between MM and HHV-8. We looked for indirect evidence of an HHV-8/MM association by evaluating whether MM is associated with KS in the United States. Cancer incidence and survival data were obtained from the Surveillance, Epidemiology, and End Results (SEER) program for the years 1973-1995. Strength of association was assessed for a number of cancer pairs using standardized incidence ratios (SIRs) (observed/expected double cancers). KS was strongly associated (SIR > 15) with non-Hodgkin's lymphoma and anal cancer, was modestly associated (2.5 < SIR < 5.5) with MM, Hodgkin's disease, and testicular cancer and was not significantly associated with 6 other cancers. Besides being associated with KS, MM was weakly associated (1.7 < SIR < 2.3) with Hodgkin's disease and testicular cancer. The SIRs for 7 other cancers paired with MM were all less than 1.6. Factors that might be responsible for the KS/MM association include MM-related immune dysfunction, HIV and HHV-8, but the role of these factors cannot be directly assessed through the SEER database. Although we cannot rule out the possibility that HHV-8 is linked to a small proportion of MM cases, the modest KS/MM association is evidence that the vast majority of MM cases are not likely to be associated with HHV-8.

Adolescent↗
PubMed1996

Long-term survival of patients with HIV-related systemic non-Hodgkin's lymphomas.

BACKGROUND: the overall outcome of patients with HIV-related non-Hodgkin's lymphomas (HIV-NHL) is poor because of the adverse clinico-pathological features of HIV-NHL and the underlying HIV infection. However, the experience of physicians in the management of HIV-NHL has increased, in particular in the use of intensive chemotherapy regimens, leading to an improvement in the prognosis of some of these neoplasms. Because some patients with AIDS may survive up to 5 years, it is possible to evaluate the long-term efficacy of the treatment of patients with HIV-NHL. In the general population, aggressive NHL, that are those occurring in HIV patients, may be considered cured after 2 years of lasting complete remission (CR) after chemotherapy. PATIENTS AND METHODS: we reviewed our monoinstitutional case-series of 73 HIV-infected patients with systemic NHL, observed between April 1985 and February 1993. Two groups of patients were arbitrarily identified, the first one (group A) including patients with a CR lasting for at least 2 years (N = 13) and the other including all remaining patients (group B) (N = 60). RESULTS: the 13 patients of group A differed significantly from the other patients in terms of higher CD4+ cell count and performance status (PS) at the time of diagnosis of NHL. There was no significant difference in the histological subtypes of the HIV-NHLs. The overall survival of the 73 patients was 8 months. In a separate analysis on all patients, age less than 30 years, PS less or equal to 1, a CD4+ cell count equal to or higher than 100/mm3 and the absence of B symptoms were significantly associated with a longer survival. The median survival in patients of group A was 42 months, however none of these patients relapsed during a median observation time of 42 months (range, 24-90). CONCLUSIONS: long-term survival and possibly cure can be obtained in some patients with HIV-NHL, in particular in those with a better PS and a less advanced immune dysfunction. In fact some of these patients are alive without evidence of disease 4 to 7 years after therapy, and others died of causes related to underlying HIV infection, in particular opportunistic infections, rather than relapse of NHL.

Adult↗
PubMed1980

Comparison of immune derangements in patients with different malignancies.

Immune function was evaluated in 109 patients with carcinoma of the breast, bladder, head and neck, and lung. Patients with head and neck cancer showed the most profound derangements of immune function; patients with lung cancer showed no detectable abnormalities. Non-irradiated patients with disseminated head and neck cancer had significantly depressed lymphocyte counts (mean 1357/mm3, P less than .05), E-rosette forming cells (mean 770/mm3, P less than .05), and response to phytohemagglutinin (P less than .05) as compared to controls. This immunodeficiency was detected in patients with localized as well as advanced disease. Although significant differences were noted between patients with head and neck cancer and the other tumors, these differences were minimized by radiation therapy. All irradiated patients showed comparable degrees of immune dysfunction. Absolute Fc-receptor cells were depressed in all irradiated patients and in non-irradiated patients with disseminated breast cancer.

Adult↗
PubMed1986

Serum beta-2 microglobulin levels in homosexual men with AIDS and with persistent, generalized lymphadenopathy.

In order to investigate the nature of the immune disorders associated with the acquired immune deficiency syndrome (AIDS) and the AIDS-related condition of persistent, generalized lymphadenopathy (PGL), serum beta-2 microglobulin (beta 2-M) levels were determined in patients with AIDS and PGL and in asymptomatic homosexual and heterosexual controls. Sixteen of 20 (80%) patients with AIDS exhibited elevated beta 2-M levels. In contrast, 20 of 44 (45%) patients with PGL, 4 of 20 (20%) asymptomatic homosexuals, and only 3 of 46 (7%) heterosexuals had increased serum beta 2-M levels (P less than 0.001). When considering mean levels of beta 2-M, only the asymptomatic control individuals had normal values. AIDS patients had significantly higher mean beta 2-M levels when compared to all other groups (P less than 0.05). The mean level for PGL patients was greater than that in the homosexual and heterosexual controls (P less than 0.05). No relationship was found between presence of antibody to human T-lymphotropic retrovirus (HTLV-III) and beta 2-M levels in the patients with AIDS or PGL. The authors conclude that beta 2-M is elevated in patients with AIDS and PGL, suggesting an increased turnover of a certain subpopulation of lymphocytes in these patients. Beta 2-M levels also appear to parallel disease activity, as well as immune dysfunction, with the greatest elevation occurring in patients with AIDS, followed by those with PGL, and asymptomatic homosexuals. Beta 2-M levels may be a useful confirmatory marker in AIDS and its related disorders.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Observations of serum trace elements in chronic lymphocytic leukemia.

Serum trace elements (STE) were measured in 50 patients with chronic lymphocytic leukemia (CLL) and 100 normal subjects. Copper was higher in patients than in controls (1.50 +/- 0.06 versus 1.10 +/- 0.02 micrograms/ml, P less than 0.001), increased steadily from Stage 0 to Stage 4 (P = 0.002), and correlated with the lymphocyte count and serum lactate dehydrogenase (P less than 0.01) but not with acute phase reactants. Zinc was lower in patients than in controls (0.94 +/- 0.03 versus 1.10 +/- 0.02 micrograms/ml, P less than 0.001). Zinc (NS), selenium (P = 0.039), and calcium (P = 0.033), were decreased in Stages 3-4 as compared to Stages 0-2. The copper-to-zinc ratio (CZR) increased continuously from Stage 0 to Stage 4 (P less than 0.001). Discriminant analysis between two groups, Stage 0-2 and Stage 3-4, based on serum copper, zinc, calcium, and protein levels, allowed for a correct classification of 94% of the patients. Moreover, the clinical staging of the remaining 6% was modified retrospectively according to the results of discriminant analysis. It was concluded that (1) serum copper and CZR are useful indices of the extent of disease, (2) they are independent of a nonspecific acute phase reaction, (3) STE determination could be helpful in the staging of a limited number of CLL patients, and (4) zinc deficiency could contribute to immune dysfunction in CLL.

Aged↗
PubMed1990

Advanced acquired immune deficiency syndrome-related Kaposi's sarcoma. Results of pilot studies using combination chemotherapy.

Pilot studies were conducted to evaluate the toxicity and efficacy of two relatively marrow-sparing chemotherapy regimens in the treatment of advanced or progressive epidemic Kaposi's sarcoma. Chemotherapy regimens consisted of bleomycin (10 mg/m2), vincristine (1.4 mg/m2, 2 mg maximum) and Adriamycin (doxorubicin) at either 10 mg/m2 (Group I) or 20 mg/m2 (Group II). The therapy was given intravenously, every 2 weeks, until intolerable toxicity or maximum antitumor response. Thirty-three patients were treated. Although the patient populations were similar regarding pretreatment prognostic factors, the patients were not assigned randomly to these two treatment regimens. Major responses (complete or partial remission) were attained in 79% of the cases. The treatment-related toxicities consisted of mild to moderate nausea, hair loss, and peripheral sensory neuropathy. Bone marrow suppression consisted primarily of neutropenia (less than 1000/mm3) which occurred in a third of the patients. Variables significantly associated with shorter survival included hemoglobin (less than 10 g/dl), low Karnofsky performance status (less than 70%), and weight loss. Opportunistic infections occurred in the majority of cases during administration of chemotherapy, and were most likely related to severe cell-mediated immune dysfunction and low CD4-positive lymphocyte counts.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Peripheral T-cell lymphomas. Immunoregulatory cytokine (interleukin-2, interleukin-4, and interferon-gamma) abnormalities and autologous mixed lymphocyte reaction.

BACKGROUND: Cytokines are the most important secretions of the immune system and have a wide range of immunoregulatory functions in various immune disorders and T-cell malignancy. The authors have determined that characteristic enhanced autologous mixed lymphocyte reaction (AMLR) of the lymph node-derived malignant T-cells from peripheral T-cell lymphomas is a function of the T-cell derived cytokines interleukin (IL)-2, IL-4, and interferon-gamma (IFN-tau). METHODS: Autologous mixed lymphocyte reaction assay was performed by the standard proliferative response (3H-thymidine incorporation), by culturing autologous lymph node-derived or blood-purified T-cells with autologous blood-purified mitomycin-c treated non-T-cells. The production of IL-2, IL-4, and IFN-tau in the AMLR cultures was determined by bioassay or enzyme immunoassays. RESULTS: Enhanced IL-2 and IFN-tau but deficient IL-4 production is the most characteristic and unique feature of the augmented AMLR in peripheral T-cell lymphomas. CONCLUSION: The immunoregulatory aberrations in lymph node-derived malignant T-cells that produce highly elevated IL-2 and IFN-tau but decreased IL-4 during augmented AMLR may play an important role in immune dysfunction in this neoplasm (peripheral T-cell lymphomas).

Aged↗
PubMed1995

Cytokines in immune regulation/pathogenesis in HIV infection.

Two hallmarks of immunopathogenesis in the progression of HIV-infected individuals to AIDS are the loss of T helper (Th) cell function in response to antigens and the critical reduction in CD4+ T cell numbers. It is probable that these two phenomena are related. We observed that: (1) the failure to detect antigen-stimulated Th cell responses in vitro correlates with increased pokeweed mitogen/staphylococcal enterotoxin B (P/S)-stimulated and antigen-stimulated T cell death; and (2) both of these events are similarly modulated by immunoregulatory cytokines. Interleukin 2 (IL-2) and IL-12 (Th1-type cytokines), as well as antibodies to IL-4 and IL-10 (which are Th2-type cytokines) restore in vitro Th cell responses to recall antigens such as influenza virus and HIV envelope synthetic peptides (env). P/S-induced T cell death affects both CD4+ and CD8+ T cell subsets, whereas death induced by stimulation with env affects only CD4+ T cells. In both examples, Th1-type cytokines and antibodies to Th2-type cytokines protect against T cell death. In contrast, IL-4 and IL-10 do not protect against death, and anti-IL-12 antibody can enhance T cell death. Our findings indicate that the loss of Th cell function and increased T cell death seen in vitro are correlated, and that in vivo HIV infection gives rise to inappropriate cytokines resulting in immune dysfunction and immunopathogenesis.

Cytokines↗
PubMed1989

Hodgkin disease in a patient with common variable immunodeficiency.

Extensive extralymphatic Hodgkin disease developed in a young man with common variable immunodeficiency manifested by hypogammaglobulinemia, recurrent sinopulmonary infections, and multiple autoimmune phenomena. Both humoral and cell-mediated immune dysfunction were present prior to treatment. After two cycles of chemotherapy, irreversible shock developed, and death occurred secondary to overwhelming infection in spite of prophylactic gammaglobulin replacement. The unusual features of this patient's case of extralymphatic Hodgkin disease in association with a primary immunodeficiency disorder have not been previously reported.

Adult↗
PubMed1990

Human immunodeficiency virus-1 disease progression in hemophiliacs.

A retrospective study of 153 hemophiliacs infected with human immunodeficiency virus-1 (HIV-1) was performed to determine the clinical and immunological consequences of HIV-1 infection and the markers and cofactors associated with these changes. Nearly 80% of HIV-1-infected hemophiliacs have developed a significant reduction in their CD-4+ counts (less than 400 CD-4+ cells/mm3) with 40% having less than 200 CD-4+ cells/mm3 by the end of 1987. The rate of CD-4+ cell count decline was slightly greater in patients who have already developed the acquired immunodeficiency syndrome (AIDS) compared to those who have not (50 vs. 31 cells/mm3/6 months). Thrombocytopenia and older age were associated with a more rapid CD-4+ count deterioration, but the quantity of clotting factor utilized did not affect immunologic progression. In patients with less than 200 CD-4+ cells/mm3, the incidence of AIDS was significantly higher in adults (greater than 21 years old) compared to children/adolescents. Cytomegalovirus (CMV) seroprevalence increased with age but did not correlate with the amount of concentrated clotting factor used. Although there was no relationship between CMV status and progression to AIDS, CMV-seropositive patients were older and had a lower CD-4+ count. Thus the majority of HIV-1-infected hemophiliacs are developing progressive immune dysfunction measured by CD-4+ count decline. This drop in CD-4+ count significantly correlates with a risk for the development of AIDS in adults but not in children (less than 21 years old).

Acquired Immunodeficiency Syndrome↗
PubMed2003

Pediatric medicine and the genetic disorders of the Amish and Mennonite people of Pennsylvania.

The Clinic for Special Children in Lancaster County, Pennsylvania, is a community-supported, nonprofit pediatric medical practice for Amish and Mennonite children who have genetic disorders. Over a 14-year period, 1988-2002, we have encountered 39 heritable disorders among the Amish and 23 among the Mennonites. We emphasize early recognition and long-term medical care of children with genetic conditions. In the clinic laboratory we perform amino acid analyses by high-performance liquid chromatography (HPLC), organic acid analyses by gas chromatography/mass spectrometry (GC/MS), and molecular diagnoses and carrier tests by polymerase chain reaction (PCR) amplification and sequencing or restriction digestion. Regional hospitals and midwives routinely send whole-blood filter paper neonatal screens for tandem mass spectrometry and other modern analytical methods to detect 14 of the metabolic disorders found in these populations as part of the NeoGen Inc. Supplemental Newborn Screening Program (Pittsburgh, PA). Medical care based on disease pathophysiology reduces morbidity, mortality, and costs for the majority of disorders. Among our patients who are homozygous for the same mutation, differences in disease severity are not unusual. Clinical problems typically arise from the interaction of the underlying genetic disorder with common infections, malnutrition, injuries, and immune dysfunction that act through classical pathophysiological disease mechanisms to influence the natural history of disease.

Ethnicity↗
PubMed1980

Autosomal dominant cerebrovascular amyloidosis: properties of peripheral blood lymphocytes.

Selected properties of peripheral blood lymphocytes (PBLs) from five ambulatory affected individuals of a kindred with autosomal dominant cerebrovascular amyloidosis were studied. The percentage of PBLs bearing surface membrane immunoglobulin (SmIg+ cells) was increased in the patient group (30 +/- 3% versus 20 +/- 2%; p less than 0.05). The percentage of PBLs forming early and total E-rosettes was comparable in patient and control groups. Mitogenic response to concanavalin A (Con A) was suggestively reduced in the patient group, measured both by total 3H-thymidine incorporation and by comparison of stimulation indices. Mitogenic response to phytohemagglutinin and pokeweed was comparable in the two groups. Capping of Con A by PBLs was significantly reduced in the patient group compared with the controls (13 +/- 1% versus 26 +/- 2%; p less than 0.01). The findings of reduced Con A response and increased SmIg+ cells support the hypothesis that immune dysfunction contributes to the development of amyloidosis. The reduced capping suggests altered membrane properties in this autosomal dominant disorder.

Adult↗
PubMed1985

Amyotrophic lateral sclerosis: Part 2. Etiopathogenesis.

The pathogenesis of the motor neuronal degeneration in amyotrophic lateral sclerosis (ALS) is unclear, though several possible etiological factors are currently being investigated. A unifying hypothesis will have to explain the diverse geographical occurrence, clinical features, and selective vulnerability and relative resistance of different neuronal populations in the disease. It is possible that different biochemical defects underlie this diversity, or alternatively that the many factors incriminated in the etiology may act upon an underlying genetic-biochemical abnormality to trigger premature neuronal death. Viruses, metals, endogenous toxins, immune dysfunction, endocrine abnormalities, impaired DNA repair, altered axonal transport, and trauma have all been etiologically linked with ALS, but convincing research evidence of a causative role for any of these factors is yet to be demonstrated.

Aged↗