Immunological abnormalities in patients with chronic fatigue syndrome. Tirelli U, Marotta G, Improta S, Pinto A.Scandinavian Journal of Immunology 1994; 40(6): 601-8.

Abstract: Between January 1991 and January 1993, 265 patients who fulfilled the CDC criteria of the working case definition of Chronic Fatigue Syndrome (CFS) have been observed at our Institution and submitted for clinical and laboratory evaluation. One hundred and sixty-three patients were females and 102 males, the median age was 35 years (range 4-55 years); all patients reported profound and prolonged fatigue, lasting for a median of 3 years (range 6 months-10 years), preceded or accompanied at appearance by fever in 185 cases, and neuropsychologic problems including inability to concentrate, difficulty in thinking, confusion, irritability, forgetfulness, and depression. The fatigue was so severe that it required 102 patients to stop their working activities for a period of time ranging from 3 months to 2 years (range 7 months). In 40 consecutive patients a comprehensive immunologic testing by single and two-colour flow cytometry was performed and results compared with a group of 35 healthy, age- and sex-matched controls. Whilst no significant differences were found in the absolute numbers of circulating total T cells (CD3+) and of total helper/inducer (CD4+) or suppressor/cytotoxic (CD8+) T cells, an evident reduction in CD3-/CD16+ and CD57+/CD56+ NK lymphocytes along with an expansion of the CD8+/CD56+ and CD16-/CD56+ NK subsets, were found in the CFS group. In addition, CD56+ NK cells from CFS subjects were found to express an increased amount of cell adhesion molecules (CD11b, CD11c, CD54) and activation antigens (CD38). Both the percentage and absolute numbers of CD4+ T cells bearing the CD45RA antigen appeared significantly reduced in CFS patients, and CD4+ T lymphocytes from CFS subjects displayed an increased expression of the intercellular adhesion molecule-1 (ICAM-1/CD54). Finally, the total numbers of circulating (CD19+) B lymphocytes, were significantly higher in CFS cases than in controls, and in 11 out of 30 CFS patients the increase in circulating B cells was sustained by the expansion of the CD5+/CD19+ subset of B lymphocytes. We conclude that CFS is a syndrome not previously described in Italy, with already known clinical characteristics and appears to be associated with several immunologic abnormalities, including those reported previously in cohort of patients from different countries. We also show for the first time that CD56- NK cell subsets from CFS patients display an abnormally increased expression of cell adhesion molecules and activation markers.

Characteristic T cell dysfunction in patients with chronic active Epstein-Barr virus infection (chronic infectious mononucleosis). Tosato G et al. Journal of Immunology 1985; 134: 3082-8.

Abstract: We evaluated immune functions in 16 patients with chronic active Epstein-Barr virus (EBV) infection (chronic infectious mononucleosis). Chronic infectious mononucleosis is an illness characterized primarily by chronic and occasionally disabling fatigue and other constitutional complaints, only sometimes beginning with an episode of acute infectious mononucleosis, and associated with an abnormal pattern of serum antibodies to EBV. In these patients, the frequency of circulating EBV-infected B cells that manifested spontaneous outgrowth in vitro was comparable to that found in EBV-seropositive normals, and the levels of EBV-specific suppressor activity were also normal. Upon stimulation with polyclonal activators, unseparated cells from these patients produced a relatively normal number of immunoglobulin-secreting cells. However, when purified T cells from these patients were mixed with normal mononuclear cells in co-culture, immunoglobulin production was strikingly suppressed. The degree of this T cell suppression correlated directly with the abnormally elevated titer of antibody to the early antigens of EBV. Interestingly, during normal convalescence from acute EBV-induced infectious mononucleosis a period is also seen during which T cells suppress the response of allogeneic but not autologous cells. Thus, from an immunologic viewpoint, patients with chronic active EBV infection appear "frozen" in a state typically found only briefly during the convalescence from acute EBV infection.

Consequences of live poliovirus vaccine administration in chronic fatigue syndrome. Vedhara K, Llewelyn MB, Fox JD, Jones M, Jones R, Clements GB, Wang EC, Smith AP, Borysiewicz LK. Journal of Neuroimmunology 1997; 75(1-2): 183-195.

Abstract: The effect of live oral polio virus vaccination on chronic fatigue syndrome (CFS) patients was examined in a double-blind study. CFS patients were allocated randomly to placebo (N = 7) or vaccine (N = 7) conditions. All controls subjects received the vaccine (9). Vaccine administration was not associated with clinical exacerbation of CFS. However, objective responses to the vaccine revealed differences between patients and controls: increased poliovirus isolation, earlier peak proliferative responses, lower T-cell subsets on certain days post vaccination and a trend for reduced gamma-interferon in the CFS-vaccine group. Polio vaccination was not found to be clinically contraindicated in CFS patients, however, there was evidence of altered immune reactivity and virus clearance.

Gamma globulin therapy for chronic mononucleosis syndrome. Dubois RE. AIDS Research 1986; 2(1): 191-5.

Abstract: Antibodies against Epstein-Barr virus, associated with antibody dependent cytotoxic cell activity, were found to be present in diminished titer in 20 of 22 patients tested with chronic mononucleosis syndrome (CMS). Gamma globulin was shown to improve symptoms in 53% of the patients treated, compared with 32% of placebo injections. 89.5% of 57 patients treated with a gamma globulin treatment program remained in the treatment program because of relief of symptoms, and only four patients dropped out because there was no relief of symptoms or side effects. Four patients experienced complete relief of symptoms following a variable length treatment program. It would appear that intramuscular gamma globulin treatment is efficacious in the treatment of CMS and that the average interval between treatments is three weeks.

A double-blind, placebo-controlled trial of intravenous immunoglobulin therapy in patients with chronic fatigue syndrome. Lloyd A, Hickie I, Wakefield D, Boughton CR. AAmerican Journal of Medicine 1990; 89: 561-68.

Abstract: PURPOSE: The chronic fatigue syndrome (CFS) is characterized by profound fatigue, neuropsychiatric dysfunction, and frequent abnormalities in cell-mediated immunity. No effective therapy is known. PATIENTS AND METHODS: Forty-nine patients (40 with abnormal cell-mediated immunity) participated in a randomized, double-blind, placebo-controlled trial to determine the effectiveness of high-dose intravenously administered immunoglobulin G. The patients received three intravenous infusions of a placebo solution or immunoglobulin at a dose of 2 g/kg/month. Assessment of the severity of symptoms and associated disability, both before and after treatment, was completed at detailed interviews by a physician and psychiatrist, who were unaware of the treatment status. In addition, any change in physical symptoms and functional capacity was recorded using visual analogue scales, while changes in psychologic morbidity were assessed using patient-rated indices of depression. Cell-mediated immunity was evaluated by T-cell subset analysis, delayed-type hypersensitivity skin testing, and lymphocyte transformation with phytohemagglutinin. RESULTS: At the interview conducted by the physician 3 months after the final infusion, 10 of 23 (43%) immunoglobulin recipients and three of the 26 (12%) placebo recipients were assessed as having responded with a substantial reduction in their symptoms and recommencement of work, leisure, and social activities. The patients designated as having responded had improvement in physical, psychologic, and immunologic measures (p less than 0.01 for each). CONCLUSION: Immunomodulatory treatment with immunoglobulin is effective in a significant number of patients with CFS, a finding that supports the concept that an immunologic disturbance may be important in the pathogenesis of this disorder.

Low NK syndrome and its relationship to chronic fatigue syndrome. Aoki T, Miyakoshi H, Usuda Y, Herberman RB. Clinical Immunology and Immunopathology 1993; 69(3): 253-65.

Immunologic abnormalities associated with chronic fatigue syndrome. Barker E, Fujimura SF, Fadem MB, Landay AL, Levy JA. Clinical Infectious Diseases 1994; 18(Supp 1): S136-41.

Abstract: Several aspects of cellular immunity in patients with clinically defined chronic fatigue syndrome (CFS) were evaluated and compared with those in healthy individuals. Flow cytometric analyses revealed normal expression of total T (CD3+), B (CD19+), and NK (natural killer) (CD16+, CD56+) markers on the surface of peripheral blood mononuclear cells (PMC) from patients with CFS. However, compared with those of healthy individuals, patients' CD8+ T cells expressed reduced levels of CD11b and expressed the activation markers CD38 and HLA-DR at elevated levels. In many of the individuals in whom expression of CD11b was reduced the expression of CD28 was increased. These findings indicate expansion of a population of activated CD8+ cytotoxic T lymphocytes. A marked decrease in NK cell activity was found in almost all patients with CFS, as compared with that in healthy individuals. No substantial abnormalities in monocyte activity or T cell proliferation were observed. The results of this study suggest that immune cell phenotype changes and NK cell dysfunction are common manifestations of CFS.

Phenotypic and functional deficiency of natural killer cells in patients with chronic fatigue syndrome. Caligiuri M, Murray C, Buchwald D, Levine H, Cheney P, Peterson D, Komaroff AL, Ritz J. Journal of Immunology 1987; 139: 3306-13.

Abstract: Natural killer (NK)3 cells are large granular lymphocytes that appear to play a significant role in the host's defense against viral infection. We performed an extensive phenotypic and functional characterization of NK cells on 41 patients with the chronic fatigue syndrome (CFS), or "chronic active Epstein-Barr virus infection" syndrome, and on 23 age- and sex-matched asymptomatic control subjects in an attempt to further characterize this illness. These studies demonstrated that a majority of patients with CFS have low numbers of NKH1+T3- lymphocytes, a population that represents the great majority of NK cells in normal individuals. CFS patients had normal numbers of NKH1+T3+ lymphocytes, a population that represents a relatively small fraction of NK cells in normal individuals. When tested for cytotoxicity against a variety of different target cells, patients with CFS consistently demonstrated low levels of killing. After activation of cytolytic activity with recombinant interleukin 2, patients were able to display increased killing against K562 but most patients remained unable to lyse Epstein-Barr virus-infected B cell targets. Additional cytotoxicity experiments were carried out utilizing anti-T3 monoclonal antibody to block killing by NKH1+T3+ cells. These experiments indicated that the NK cell that appears to be responsible for much of the functional activity remaining in patients with CFS belongs to the NKH1+T3+ subset, which under normal circumstances represents only approximately 20% of the NK cell population.

Immune function in chronic active Epstein-Barr virus infection. Kibler R, Lucas RO, Hicks MJ, et al. Journal of Clinical Immunology 1985; 5: 46-54.

Abstract: The spectrum of illness attributed to Epstein-Barr virus (EBV) includes patients with symptoms persisting for more than 1 year without any other obvious underlying disease. High titers of antibodies to EBV, either IgG antiviral capsid antigen or anti-early antigen, can be demonstrated. In this study, 13 patients diagnosed as having chronic active EBV infection were examined to determine aspects of their immunologic status. Morphological examination and fluorescent antibody analysis revealed no abnormalities in the phenotypes of peripheral blood white cells present in these patients. Compared to those from healthy control individuals, mononuclear cells from the patients showed a markedly depressed ability to produce both interleukin-2 and interferon after stimulation with mitogen and a phorbol ester. Studies of natural killer (NK) cell activity revealed that unfractionated mononuclear cells from patients with chronic active EBV infection were significantly lower in killing activity compared to the control group. Fractionation procedures to enrich for large granular lymphocytes resulted in an increase in NK activity for all individuals, but killing activity still remained slightly lower in the patients than in the control group. The dysfunctions which were found in patients with chronic active EBV infection may reflect a primary defect in natural immune functions of the patients predisposing them to a chronic or intermittent clinical disease rather than a self-limiting illness. Alternatively, the abnormalities detected in these experiments may be a result of the viral infection itself.

Immune responses associated with CFS: a case-control study. Mawle AC, Nisenbaum R, Dobbins JG, Gary HE Jr, Stewart JA, Reyes M, Steele L. Journal of Infectious Diseases 1997; 175(1): 136-41.

Abstract: An exploratory case-control study was conducted to assess whether the many reported differences in the immune function of chronic fatigue syndrome (CFS) patients are detectable in rigorously defined cases of CFS. Although many studies have reported differences between cases and controls in various measures of immune function, none of these differences were found in all studies. In this study, no differences were found in white blood cell numbers; immune complex, complement, or serum immunoglobulin levels; delayed type hypersensitivity and allergic responses; NK cell function; and proliferative responses to mitogens and antigens. Marginal differences were detected in cytokine responses and in cell surface markers in the total CFS population. However, when the patients were subgrouped by type of disease onset (gradual or sudden) or by how well they were feeling on the day of testing, more pronounced differences were seen.

Changes in natural killer cell phenotype in patients with post-viral fatigue syndrome. Morrison LJA, Behan WHM, Behan PO. Clinical and Experimental Immunology 1991; 83: 441-6.

Abstract: We analysed peripheral blood CD56+ natural killer (NK) cell subsets in 23 carefully characterized patients with post-viral fatigue syndrome (PFS), compared with 19 healthy controls, using fluorochrome-conjugated, specific monoclonal antibodies and the FACScan. We found significantly increased percentages of CD56+, and especially CD56bright+ NK cells in PFS patients. We also found significantly increased percentages of CD56+ high affinity interleukin-2 (IL-2) receptor (CD25)+ and CD56+ transferrin receptor (CD71+) subsets of cells, most of which also stained brightly for CD56. Also, we found an increased percentage of CD56+ CD3+ cells, many of which stained brightly for CD56, although there was no increase in the percentage of CD56- CD3+ T cells in these patients. These observations, in conjunction with very low percentage of CD56- CD25+ cells, suggest that there is a preferential involvement of this minor subset of CD56+ CD3+ T cells in PFS. Finally, a decreased percentage of CD56+ Fc gamma receptor (CD16)+ NK cells was identified, which suggests a reduced capacity of antibody-dependent cellular cytotoxicity in PFS patients. Subsets of CD56+ NK cells co-expressing CD2, CD4 or CD8 did not show any significant difference between PFS patients and healthy controls. These phenotypic changes provide laboratory evidence of immunological abnormalities in this syndrome, and, we suggest, may be consistent with persistent viral infection.

Decreased natural killer cell activity is associated with severity of chronic fatigue immune dysfunction syndrome. Ojo-Amaize EA, Conley EJ, Peter JB. Clinical Infectious Diseases 1994; 18(Supp 1): S157-S159.

Abstract: Natural killer (NK) cell activity was measured blindly in vitro with blood specimens from 50 healthy individuals and 20 patients with clinically defined chronic fatigue immune dysfunction syndrome (CFIDS) who met the criteria established by the Centers for Disease Control and Prevention (Atlanta). In accordance with a group scoring system of 1-10 points, with 10 being the most severe clinical status, the patient population was stratified into three clinical groups: A (> 7 points), B (5-7 points), and C (< 5 points). NK cell activity was assessed by the number of lytic units (LU), which for the 50 healthy controls varied between 20 and 250 (50%, 20-50 LU; 32%, 51-100 LU; 6%, 101-130 LU; and 12%,> 150 LU). In none of the 20 patients with CFIDS was the NK cell activity > 100 LU. For group C, the 10 patients stratified as having the least severe clinical condition, the measure was 61.0 ± 21.7 LU; for group B (more severe, n = 7), it was 18.3 ± 7.3 LU; and for group A (most severe, n = 3), it was 8.0 ± 5.3 LU. These data suggest a correlation between low levels of NK cell activity and severity of CFIDS, which, if it is confirmed by additional studies of larger groups, might be useful for subgrouping patients and monitoring therapy and/or the progression of CFIDS.