Defining Kawasaki disease and pediatric inflammatory multisystem syndrome-temporally associated to SARS-CoV-2 infection during SARS-CoV-2 epidemic in Italy: results from a national, multicenter survey

BACKGROUND

There is mounting evidence on the existence of a Pediatric Inflammatory Multisystem Syndrome-temporally associated to SARS-CoV-2 infection (PIMS-TS), sharing similarities with Kawasaki Disease (KD). The main outcome of the study were to better characterize the clinical features and the treatment response of PIMS-TS and to explore its relationship with KD determining whether KD and PIMS are two distinct entities.

METHODS

The Rheumatology Study Group of the Italian Pediatric Society launched a survey to enroll patients diagnosed with KD (Kawasaki Disease Group - KDG) or KD-like (Kawacovid Group - KCG) disease between February 1st 2020, and May 31st 2020. Demographic, clinical, laboratory data, treatment information, and patients' outcome were collected in an online anonymized database (RedCAP®). Relationship between clinical presentation and SARS-CoV-2 infection was also taken into account. Moreover, clinical characteristics of KDG during SARS-CoV-2 epidemic (KDG-CoV2) were compared to Kawasaki Disease patients (KDG-Historical) seen in three different Italian tertiary pediatric hospitals (Institute for Maternal and Child Health, IRCCS "Burlo Garofolo", Trieste; AOU Meyer, Florence; IRCCS Istituto Giannina Gaslini, Genoa) from January 1st 2000 to December 31st 2019. Chi square test or exact Fisher test and non-parametric Wilcoxon Mann-Whitney test were used to study differences between two groups.

RESULTS

One-hundred-forty-nine cases were enrolled, (96 KDG and 53 KCG). KCG children were significantly older and presented more frequently from gastrointestinal and respiratory involvement. Cardiac involvement was more common in KCG, with 60,4% of patients with myocarditis. 37,8% of patients among KCG presented hypotension/non-cardiogenic shock. Coronary artery abnormalities (CAA) were more common in the KDG. The risk of ICU admission were higher in KCG. Lymphopenia, higher CRP levels, elevated ferritin and troponin-T characterized KCG. KDG received more frequently immunoglobulins (IVIG) and acetylsalicylic acid (ASA) (81,3% vs 66%; p = 0.04 and 71,9% vs 43,4%; p = 0.001 respectively) as KCG more often received glucocorticoids (56,6% vs 14,6%; p < 0.0001). SARS-CoV-2 assay more often resulted positive in KCG than in KDG (75,5% vs 20%; p < 0.0001). Short-term follow data showed minor complications. Comparing KDG with a KD-Historical Italian cohort (598 patients), no statistical difference was found in terms of clinical manifestations and laboratory data.

CONCLUSION

Our study suggests that SARS-CoV-2 infection might determine two distinct inflammatory diseases in children: KD and PIMS-TS. Older age at onset and clinical peculiarities like the occurrence of myocarditis characterize this multi-inflammatory syndrome. Our patients had an optimal response to treatments and a good outcome, with few complications and no deaths.

Defining Kawasaki disease and pediatric inflammatory multisystem syndrome-temporally associated to SARS-CoV-2 infection during SARS-CoV-2 epidemic in Italy: results from a national, multicenter survey

BACKGROUND

There is mounting evidence on the existence of a Pediatric Inflammatory Multisystem Syndrome-temporally associated to SARS-CoV-2 infection (PIMS-TS), sharing similarities with Kawasaki Disease (KD). The main outcome of the study were to better characterize the clinical features and the treatment response of PIMS-TS and to explore its relationship with KD determining whether KD and PIMS are two distinct entities.

METHODS

The Rheumatology Study Group of the Italian Pediatric Society launched a survey to enroll patients diagnosed with KD (Kawasaki Disease Group - KDG) or KD-like (Kawacovid Group - KCG) disease between February 1st 2020, and May 31st 2020. Demographic, clinical, laboratory data, treatment information, and patients' outcome were collected in an online anonymized database (RedCAP®). Relationship between clinical presentation and SARS-CoV-2 infection was also taken into account. Moreover, clinical characteristics of KDG during SARS-CoV-2 epidemic (KDG-CoV2) were compared to Kawasaki Disease patients (KDG-Historical) seen in three different Italian tertiary pediatric hospitals (Institute for Maternal and Child Health, IRCCS "Burlo Garofolo", Trieste; AOU Meyer, Florence; IRCCS Istituto Giannina Gaslini, Genoa) from January 1st 2000 to December 31st 2019. Chi square test or exact Fisher test and non-parametric Wilcoxon Mann-Whitney test were used to study differences between two groups.

RESULTS

One-hundred-forty-nine cases were enrolled, (96 KDG and 53 KCG). KCG children were significantly older and presented more frequently from gastrointestinal and respiratory involvement. Cardiac involvement was more common in KCG, with 60,4% of patients with myocarditis. 37,8% of patients among KCG presented hypotension/non-cardiogenic shock. Coronary artery abnormalities (CAA) were more common in the KDG. The risk of ICU admission were higher in KCG. Lymphopenia, higher CRP levels, elevated ferritin and troponin-T characterized KCG. KDG received more frequently immunoglobulins (IVIG) and acetylsalicylic acid (ASA) (81,3% vs 66%; p = 0.04 and 71,9% vs 43,4%; p = 0.001 respectively) as KCG more often received glucocorticoids (56,6% vs 14,6%; p < 0.0001). SARS-CoV-2 assay more often resulted positive in KCG than in KDG (75,5% vs 20%; p < 0.0001). Short-term follow data showed minor complications. Comparing KDG with a KD-Historical Italian cohort (598 patients), no statistical difference was found in terms of clinical manifestations and laboratory data.

CONCLUSION

Our study suggests that SARS-CoV-2 infection might determine two distinct inflammatory diseases in children: KD and PIMS-TS. Older age at onset and clinical peculiarities like the occurrence of myocarditis characterize this multi-inflammatory syndrome. Our patients had an optimal response to treatments and a good outcome, with few complications and no deaths.

A 53-Year-Old Man Presents to the ED With Shortness of Breath, Cough, and Fever

A 53-year-old man presented to the ED at a time of low severe acute respiratory syndrome coronavirus 2, also known as coronavirus disease 2019 (COVID-19), prevalence and reported 2 weeks of progressive shortness of breath, dry cough, headache, myalgias, diarrhea, and recurrent low-grade fevers to 39°C for 1 week with several days of recorded peripheral capillary oxygen saturation of 80% to 90% (room air) on home pulse oximeter. Five days earlier, he had visited an urgent care center where a routine respiratory viral panel was reportedly negative. A COVID-19 reverse transcriptase polymerase chain reaction test result was pending at the time of ED visit. He reported a past medical history of gastroesophageal reflux disease that was treated with famotidine. Travel history included an out-of-state trip 3 weeks earlier, but no recent international travel.

Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures

By 27 February 2020, the outbreak of coronavirus disease 2019 (COVID-19) caused 82 623 confirmed cases and 2858 deaths globally, more than severe acute respiratory syndrome (SARS) (8273 cases, 775 deaths) and Middle East respiratory syndrome (MERS) (1139 cases, 431 deaths) caused in 2003 and 2013, respectively. COVID-19 has spread to 46 countries internationally. Total fatality rate of COVID-19 is estimated at 3.46% by far based on published data from the Chinese Center for Disease Control and Prevention (China CDC). Average incubation period of COVID-19 is around 6.4 days, ranges from 0 to 24 days. The basic reproductive number (R₀ ) of COVID-19 ranges from 2 to 3.5 at the early phase regardless of different prediction models, which is higher than SARS and MERS. A study from China CDC showed majority of patients (80.9%) were considered asymptomatic or mild pneumonia but released large amounts of viruses at the early phase of infection, which posed enormous challenges for containing the spread of COVID-19. Nosocomial transmission was another severe problem. A total of 3019 health workers were infected by 12 February 2020, which accounted for 3.83% of total number of infections, and extremely burdened the health system, especially in Wuhan. Limited epidemiological and clinical data suggest that the disease spectrum of COVID-19 may differ from SARS or MERS. We summarize latest literatures on genetic, epidemiological, and clinical features of COVID-19 in comparison to SARS and MERS and emphasize special measures on diagnosis and potential interventions. This review will improve our understanding of the unique features of COVID-19 and enhance our control measures in the future.

Primary intestinal lymphangiectasia in an elderly female patient: A case report on a rare cause of secondary immunodeficiency

Protein loss via the gut can be caused by a number of gastrointestinal disorders, among which intestinal lymphangiectasia has been described to not only lead to a loss of proteins but also to a loss of lymphocytes, resembling secondary immunodeficiency. We are reporting on a 75-year-old female patient who came to our hospital because of a minor stroke. She had no history of serious infections. During the diagnostic work-up, we detected an apparent immunodeficiency syndrome associated with primary intestinal lymphangiectasia. Trying to characterize the alterations of the immune system, we not only found hypogammaglobulinemia and lymphopenia primarily affecting CD4+, and also CD8+ T cells, but also marked hypocomplementemia affecting levels of complement C4, C2, and C3. The loss of components of the immune system most likely was due to a chronic loss of immune cells and proteins via the intestinal lymphangiectasia, with levels of complement components following the pattern of protein electrophoresis. Thus, intestinal lymphangiectasia should not only be considered as a potential cause of secondary immune defects in an elderly patient, but can also be associated with additional hypocomplementemia.

[Research progress of peripheral blood count test in the evaluation of prognosis of gastric cancer]

Gastric cancer (GC) is one of the most common tumor in the world, and remains a major public health problem and one of the leading causes of death. Recently many researches have demonstrated that systemic inflammatory response is associated with prognosis and response to therapy in gastric cancer, and the peripheral blood count test can partly reflect the systemic inflammatory response. Based on the peripheral blood count test, there are a lot of research regarding the relation between the platelet count (PLT), neutrophil, lymphocyte, white blood cell (WBC), neutrophil to lymphocyte ratio(NLR), platelet to lymphocyte ratio (PLR) with their prognostic role in gastric cancer. A high PLT and preoperative lymphocytopenia are both associated with increased lymph node metastasis, stage (III(+IIII(), serosal invasion (T3+T4) risk and poorer overall survival. Besides above, platelet monitoring following surgery can be applied to predict the recurrence for patients with GC that suffer preoperative high PLT but have restored PLT levels following resection. Moreover systemic inflammatory factors based on blood parameters, such as PLR, NLR and so on, have relation with the poor prognosis of patients with GC. Among them, high NLR is a negative predictor of prognosis in GC patients. However PLR remains inconsistent, while most researches demonstrated high PLR may be useful prognostic factor rather than independent prognostic factor. There are still some limitations which include various cut-off values, little of clinician attention, the uncertain mechanism, etc. Here we review the research progress in the prognostic role of the blood count test in gastric cancer.

Activation-induced necroptosis contributes to B-cell lymphopenia in active systemic lupus erythematosus

B-cell abnormality including excessive activation and lymphopenia is a central feature of systemic lupus erythematosus (SLE). Although activation threshold, auto-reaction and death of B cells can be affected by intrinsical and/or external signaling, the underlying mechanisms are unclear. Herein, we demonstrate that co-activation of Toll-like receptor 7 (TLR7) and B-cell receptor (BCR) pathways is a core event for the survival/dead states of B cells in SLE. We found that the mortalities of CD19(+)CD27(-) and CD19(+)IgM(+) B-cell subsets were increased in the peripheral blood mononuclear cells (PBMCs) of SLE patients. The gene microarray analysis of CD19(+) B cells from active SLE patients showed that the differentially expressed genes were closely correlated to TLR7, BCR, apoptosis, necroptosis and immune pathways. We also found that co-activation of TLR7 and BCR could trigger normal B cells to take on SLE-like B-cell characters including the elevated viability, activation and proliferation in the first 3 days and necroptosis in the later days. Moreover, the necroptotic B cells exhibited mitochondrial dysfunction and hypoxia, along with the elevated expression of necroptosis-related genes, consistent with that in both SLE B-cell microarray and real-time PCR verification. Expectedly, pretreatment with the receptor-interacting protein kinase 1 (RIPK1) inhibitor Necrostatin-1, and not the apoptosis inhibitor zVAD, suppressed B-cell death. Importantly, B cells from additional SLE patients also significantly displayed high expression levels of necroptosis-related genes compared with those from healthy donors. These data indicate that co-activation of TLR7 and BCR pathways can promote B cells to hyperactivation and ultimately necroptosis. Our finding provides a new explanation on B-cell lymphopenia in active SLE patients. These data suggest that extrinsic factors may increase the intrinsical abnormality of B cells in SLE patients.

Prevalence of anaemia and immunological markers among ghanaian HAART-naïve HIV-patients and those on HAART

BACKGROUND

Highly active antiretroviral therapy (HAART) for people living with HIV/AIDS (PLWHA) has been generally accepted as the gold standard for the management of HIV patients but conflicting reports about the ability of HAART to improve upon the quality of life of HIV patients has cast doubts over the efficacy and the need for therapy.

OBJECTIVE

This study was conducted to assess the efficacy and ability of HAART to resolve immunological and haematological abnormalities in HIV infected patients, existent sex variations in immunological and haematological parameters and CD4 predictive ability of the study parameters.

METHODS

A total of 442 PLWHA consisting of 166 patients on HAART (28 males and 138 females) and 276 HAART-naïve patients (76 males and 200 females) were recruited for this study. Complete haemogram, immunological analysis (CD4 & CD3) and weight were measured for all the patients.

RESULTS

HAART patients were older and heavier than their naïve counterparts. The incidence of anaemia (Hb less or equal to 10.5 (63%) and PCV < 30% (37.6%)) and lymphopoenia (16.7%) in HAART-naïve patients was significantly higher compared to their counterparts on HAART (46%, 15.2% and 5.3%) respectively. 70% of HAART-naïve females had anaemia in comparison to 44% in HAART-naïve males (P = 0.0001). The likelihood of developing microcytic hypochromic anaemia in HAART-naïve patients was 5 times more compared to those on HAART (P = 0.0002). Total lymphocyte count, haemoglobin, lymphocyte count and weight were significant predictors of CD4 counts and TLC values between 1.0 - 2.0 k µL(-1) was a significant predictor of CD4 <200 cells mm(-3).

CONCLUSION

HAART has the capability of reducing the incidence of anaemia and lymphopoenia which are associated with disease progression and death in HIV infected patients. Total lymphocyte count, haemoglobin and weight could also serve as useful predictive tools in the management and monitoring of HIV infected patients in resource limited settings.

Toward effective immunotherapy for the treatment of malignant brain tumors

The immunologic treatment of cancer has long been heralded as a targeted molecular therapeutic with the promise of eradicating tumor cells with minimal damage to surrounding normal tissues. However, a demonstrative example of the efficacy of immunotherapy in modulating cancer progression is still lacking for most human cancers. Recent breakthroughs in our understanding of the mechanisms leading to full T-cell activation, and recognition of the importance of overcoming tumor-induced immunosuppressive mechanisms, have shed new light on how to generate effective anti-tumor immune responses in humans, and sparked a renewed and enthusiastic effort to realize the full potential of cancer immunotherapy. The immunologic treatment of invasive malignant brain tumors has not escaped this re-invigorated endeavor, and promising therapies are currently under active investigation in dozens of clinical trials at several institutions worldwide. This review will focus on some of the most important breakthroughs in our understanding of how to generate potent anti-tumor immune responses, and some of the clear challenges that lie ahead in achieving effective immunotherapy for the majority of patients with malignant brain tumors. A review of immunotherapeutic strategies currently under clinical evaluation, as well as an outline of promising novel approaches on the horizon, is included to provide perspective on the active and stalwart progress toward effective immunotherapy for the treatment of malignant brain tumors.

Immune depression syndrome following human spinal cord injury (SCI): a pilot study

Experimental spinal cord injury (SCI) has been identified to trigger a systemic, neurogenic immune depression syndrome. Here, we have analyzed fluctuations of immune cell populations following human SCI by FACS analysis. In humans, a rapid and drastic decrease of CD14+ monocytes (<50% of control level), CD3+ T-lymphocytes (<20%, P<0.0001) and CD19+ B-lymphocytes (<30%, P=0.0009) and MHC class II (HLA-DR)+ cells (<30%, P<0.0001) is evident within 24 h after spinal cord injury reaching minimum levels within the first week. CD15+ granulocytes were the only leukocyte subpopulation not decreasing after SCI. A contributing, worsening effect of high dose methylprednisolone cannot be excluded with this pilot study. We demonstrate that spinal cord injury is associated with an early onset of immune suppression and secondary immune deficiency syndrome (SCI-IDS). Identification of patients suffering spinal cord injury as immune compromised is a clinically relevant, yet widely underappreciated finding.

Pulmonary tuberculosis presenting as community-acquired pneumonia

OBJECTIVE AND BACKGROUND

The aims of this study were to investigate the frequency of Mycobacterium tuberculosis as a cause of community-acquired pneumonia (CAP) requiring hospitalization in Malaysia, and to define the clinical features of pulmonary tuberculosis (PTB) that distinguish it from non-TB CAP.

METHODS

A prospective study was performed on consecutive non-immunocompromised patients aged 12 years and older, who were hospitalized for CAP.

RESULTS

Of a total of 346 patients hospitalized for CAP, the aetiological agent was identified in 163 patients (47.1%). M. tuberculosis was isolated in 17 patients (4.9%). Multivariate analysis revealed that the following features were significantly associated with culture-positive PTB: duration of symptoms of more than 2 weeks before hospital admission (odds ratio (OR) 25.10; 95% confidence interval (CI) 4.63-136.05; P<0.001), history of night sweats (OR 5.43; 95% CI 1.10-26.79; P=0.038), chest radiograph showing upper lobe involvement (OR 8.23; 95% CI 1.59-42.53; P=0.012) or cavitary infiltrates (OR 19.41; 95% CI 2.94-128.19; P=0.002), total white blood cell count on admission of 12x10(9)/L or less (OR 6.28; 95% CI 1.21-32.52; P=0.029) and lymphopenia (OR 4.73; 95% CI 1.08-20.85; P=0.040).

CONCLUSION

Mycobacterium tuberculosis was not an uncommon cause of CAP requiring hospitalization in Malaysia. A longer duration of symptoms, history of night sweats, upper lobe involvement, cavitary infiltrates, lower total white blood cell count and lymphopenia were predictive of PTB.

Systemic lupus erythematosus in a multiethnic US cohort, XXXVII: association of lymphopenia with clinical manifestations, serologic abnormalities, disease activity, and damage accrual

OBJECTIVE

To determine if lymphopenia is associated with clinical/immunologic manifestations, disease activity, and disease damage in systemic lupus erythematosus (SLE).

METHODS

The study group comprised 591 patients with SLE participating in a multiethnic, longitudinal outcome study. Cumulative clinical/immunologic (per American College of Rheumatology criteria) and pharmacologic treatment variables were obtained at enrollment (T0) and last visit (TL). Lymphopenia (<1,500/mm3) was scored only when clinically attributable to SLE and not to medications or other causes. Lymphocyte counts were expressed in 4 categories per the Systemic Lupus Activity Measure (SLAM): normal (> or =1,500/mm3), mild (1,000-1,499/mm3), moderate (500-999/mm3), and marked (<500/mm3). Disease activity was assessed with the SLAM and the Physician's Global Assessment (PGA). Disease damage was determined with the Systemic Lupus International Collaborating Clinics Damage Index (SLICC-DI). The relationship of lymphopenia with cumulative clinical/immunologic and pharmacologic treatment variables was first examined, then the association between the SLAM, PGA, and SLICC-DI scores with different categories of lymphopenia was examined by generalized estimating equation (GEE) regression analyses. Ethnicity, age, and sex were entered into all regression models.

RESULTS

At T0 and TL, lymphopenia was found to be positively associated with renal involvement, leukopenia, anti-double-stranded DNA antibodies, anti-Ro antibodies, and the use of glucocorticoids, azathioprine, and methotrexate, but was negatively associated with photosensitivity. On GEE analyses, marked lymphopenia at T0 and moderate and marked lymphopenia for all visits were independently associated with higher SLAM, PGA, and SLICC-DI scores.

CONCLUSION

Lymphopenia is associated with several clinical/immunologic manifestations in SLE. Moderate and marked lymphopenia are associated with higher disease activity and damage accrual.

CD25+CD4+ regulatory T cells and memory T cells prevent lymphopenia-induced proliferation of naive T cells in transient states of lymphopenia

Lymphopenia has been associated with autoimmune pathology and it has been suggested that lymphopenia-induced proliferation of naive T cells may be responsible for the development of immune pathology. In this study we demonstrate that lymphopenia-induced proliferation is restricted to conditions of extreme lymphopenia, because neither naive nor memory T cells transferred into T cell-depleted hosts proliferate unless the depletion exceeds 90% of the peripheral repertoire. Memory CD4 T cells as well as regulatory CD4 T cells proved to be relatively resistant to depletion regimes, and both subsets restrict the expansion and phenotypic conversion of naive T cells by an IL-7R-dependent mechanism. It therefore seems unlikely that lymphopenia-induced proliferation of peripheral T cells causes deleterious side effects that result in immune pathology in states of partial and transient lymphopenia.

Persistent B-cell lymphopenia, multiorgan disease, and erythema multiforme caused by Mycoplasma pneumoniae infection

We report a 6-year-old girl in whom Mycoplasma pneumoniae infection presenting with erythema multiforme, multiorgan, and hematologic dysfunctions induced a long-standing, marked B-cell lymphopenia. An increase of CD8+ lymphocytes was also detected. We suggest that a selective cytotoxic T lymphocyte-dependent B cell lysis and the expansion of super-antigen activated CD8+ T cells may account for the multiorgan and hematologic disturbances triggered by M. pneumoniae.

Depletion of T cells by type I interferon: differences between young and aged mice

Type I IFN (IFN-I or IFN-alphabeta) plays an important role in the innate immune response against viral infection. Here we report that a potent inducer of IFN-alphabeta, polyinosinic-polycytidylic acid [poly(I:C)], led to the depletion of T cells in young, but not aged mice, and that this depletion was limited to central memory, but not effector memory, T cells. Although early activation of T cells in vivo by poly(I:C), as demonstrated by CD69, was not impaired with aging, the expression of active caspase-3 was higher in young compared with aged mice. This depletion of T cells and induction of active caspase-3 in young mice and of CD69 in both young and aged mice by poly(I:C) were blocked by anti-IFN-alphabeta Ab. Although poly(I:C) stimulated lower circulating levels of IFN-alphabeta in aged mice, administration of IFN-alphabeta after poly(I:C) did not induce depletion of T cells in aged mice. These results indicate that IFN-alphabeta plays a critical role in the depletion of T cells of young mice, and further suggest that the lower level of functional IFN-alphabeta and decreased induction of active caspase-3 in T cells of aged mice after poly(I:C) may be responsible for the increased resistance of T cells of aged mice to depletion.

Reduction of hepatic and adipose tissue glucocorticoid receptor expression with antisense oligonucleotides improves hyperglycemia and hyperlipidemia in diabetic rodents without causing systemic glucocorticoid antagonism

Glucocorticoids (GCs) increase hepatic gluconeogenesis and play an important role in the regulation of hepatic glucose output. Whereas systemic GC inhibition can alleviate hyperglycemia in rodents and humans, it results in adrenal insufficiency and stimulation of the hypothalamic-pituitary-adrenal axis. In the present study, we used optimized antisense oligonucleotides (ASOs) to cause selective reduction of the glucocorticoid receptor (GCCR) in liver and white adipose tissue (WAT) and evaluated the resultant changes in glucose and lipid metabolism in several rodent models of diabetes. Treatment of ob/ob mice with GCCR ASOs for 4 weeks resulted in approximately 75 and approximately 40% reduction in GCCR mRNA expression in liver and WAT, respectively. This was accompanied by approximately 65% decrease in fed and approximately 30% decrease in fasted glucose levels, a 60% decrease in plasma insulin concentration, and approximately 20 and 35% decrease in plasma resistin and tumor necrosis factor-alpha levels, respectively. Furthermore, GCCR ASO reduced hepatic glucose production and inhibited hepatic gluconeogenesis in liver slices from basal and dexamethasone-treated animals. In db/db mice, a similar reduction in GCCR expression caused approximately 40% decrease in fed and fasted glucose levels and approximately 50% reduction in plasma triglycerides. In ZDF and high-fat diet-fed streptozotocin-treated (HFD-STZ) rats, GCCR ASO treatment caused approximately 60% reduction in GCCR expression in the liver and WAT, which was accompanied by a 40-70% decrease in fasted glucose levels and a robust reduction in plasma triglyceride, cholesterol, and free fatty acids. No change in circulating corticosterone levels was seen in any model after GCCR ASO treatment. To further demonstrate that GCCR ASO does not cause systemic GC antagonism, normal Sprague-Dawley rats were challenged with dexamethasone after treating with GCCR ASO. Dexamethasone increased the expression of GC-responsive genes such as PEPCK in the liver and decreased circulating lymphocytes. GCCR ASO treatment completely inhibited the increase in dexamethasone-induced PEPCK expression in the liver without causing any change in the dexamethasone-induced lymphopenia. These studies demonstrate that tissue-selective GCCR antagonism with ASOs may be a viable therapeutic strategy for the treatment of the metabolic syndrome.

T cells from paroxysmal nocturnal haemoglobinuria (PNH) patients show an altered CD40-dependent pathway

Paroxysmal nocturnal haemoglobinuria (PNH) is a haematopoiesis disorder characterized by the expansion of a stem cell bearing a somatic mutation in the phosphatidylinositol glycan-A (PIG-A) gene, which is involved in the biosynthesis of the glycosylphosphatidylinositol (GPI) anchor. A number of data suggest the inability of the PIG-A mutation to account alone for the clonal dominance of the GPI-defective clone and for the development of PNH. In this context, additional immune-mediated mechanisms have been hypothesized. We focused on the analysis of T lymphocytes in three PNH patients bearing a mixed GPI(+) and GPI(-) T cell population and showing a marked cytopenia. To analyze the biological mechanisms underlying the control of T cell homeostasis in PNH, we addressed the study of CD40-dependent pathways, suggested to be of crucial relevance for the control of autoreactive T cell clones. Our data revealed significant, functional alterations in GPI(+) and GPI(-) T cell compartments. In the GPI(-) T cells, severe defects in T cell receptor-dependent proliferation, interferon-gamma production, CD25, CD54, and human leukocyte antigen-DR surface expression were observed. By contrast, GPI(+) T lymphocytes showed a significant increase of all these parameters, and the analysis of CD40-dependent pathways revealed a functional persistence of CD154 expression on the CD48(+)CD4(+) lymphocytes. The alterations of the GPI(+) T cell subset could be involved in the biological mechanisms underlying PNH pathogenesis.

Exposure to forced swim stress alters morphofunctional characteristics of the rat thymus

The aim of this study was to investigate whether chronic stress, induced by repeated daily swimming during 21 days, alters the morphofunctional parameters in the thymus of adult rats. Our results showed that chronic stress reduced thymus mass, total number of thymocytes, volume of the thymus compartments and numerical density of thymocytes within thymus inner cortex and medulla. However, the percentage of apoptotic cells and the level of corticosterone were significantly increased. The percentages of CD4-CD8-TCRalphabeta(low/high) and CD4-CD8+TCRalphabeta(-)thymocytes were significantly increased, while the percentage of the least mature CD4+CD8-SP TCRalphabeta(-) thymocytes was significantly decreased. These results show that recurred swimming procedure induces thymus hypotrophy and elevated percentage of DN TCRalphabeta(+) cells.

Homeostatic expansion of T cells during immune insufficiency generates autoimmunity

During illness and stress, the immune system can suffer a considerable loss of T cells (lymphopenia). The remaining T cells undergo vigorous compensatory expansion, known as homeostatic proliferation, to reconstitute the immune system. Interestingly, human diseases of autoimmune etiology often present with immune deficiencies such as lymphopenia. In this study, we show that reduced T cell numbers and the resulting exaggerated homeostatic-type proliferation of T cells generate autoimmunity. The cycling T cell population is short lived, and the depleted memory compartment fuels the generation of new effector T cells. A catalyst for these phenomena is the increased responses to the cytokine IL-21, a mediator that regulates T cell turnover. We conclude that poor T cell survival and lymphopenia precipitate autoimmune disease.

Driven to Autoimmunity

In the lymphoid system, T cells respond to space or under-crowding by dividing to maintain their numbers. In this issue of Cell, evidence is provided that this homeostatic proliferation, coupled with excess production of a cytokine, IL-21, is a key factor in susceptibility to autoimmune diabetes.

B cell deficiency confers protection from renal ischemia reperfusion injury

Recent data have demonstrated a role for CD4(+) cells in the pathogenesis of renal ischemia reperfusion injury (IRI). Identifying engagement of adaptive immune cells in IRI suggests that the other major cell of the adaptive immune response, B cells, may also mediate renal IRI. An established model of renal IRI was used: 30 min of renal pedicle clamping was followed by reperfusion in B cell-deficient ( mu MT) and wild-type mice. Renal function was significantly improved in mu MT mice compared with wild-type mice at 24, 48, and 72 h postischemia. mu MT mice also had significantly reduced tubular injury. Both groups of mice had similar renal phagocyte infiltration postischemia assessed by myeloperoxidase levels and similar levels of CD4(+) T cell infiltration postischemia. Peritubular complement C3d staining was also similar in both groups. To identify the contribution of cellular vs soluble mechanism of action, serum transfer into mu MT mice partially restored ischemic phenotype, but B cell transfers did not. These data are the first demonstration of a pathogenic role for B cells in ischemic acute renal failure, with a serum factor as a potential underlying mechanism of action.

Wound healing and growth factor expression in T lymphocyte deficiency

BACKGROUND

There are many clinical situations in which immune suppression or deficiency occurs. This may lead to healing impairment. The aim of the present study was to characterize the effect of T lymphocyte deficiency on wound healing, and on -platelet-derived growth factor (PDGF), bFGF (basic fibroblast growth factor) and insulin-like growth factor-1 (IGF-1) expression, using an animal model.

METHODS

Nude and normal 10-12-week-old male BALB/c mice were given standard dermal incisions and killed at 1, 2, 4 or 6 weeks postinjury. The pelts were harvested and the wounds cut (perpendicularly) into strips for analysis. Strips from each animal were tested mechanically or processed for histological assessment and immunohistochemical detection of PDGF, bFGF and IGF-1 and colour video image analysis. The data were assessed by analysis of variance (anova).

RESULTS

The interaction between species and time resulted in statistically significant differences in mechanical properties. Wound peak load was higher in nude mice at weeks 1 and 2 postinjury, but lower in nude mice at week 6 postinjury. Colour video image analysis demonstrated that the expression of bFGF and IGF-1 was greater in nude mice at week 1 postinjury (P < 0.05).

CONCLUSIONS

The mechanical data suggest that the overall effect of the T lymphocyte system on wound healing is initially inhibitory and later stimulatory. This may be associated with corresponding differences in wound growth factor expression.

Prolonged exercise, lymphocyte apoptosis and F2-isoprostanes

Exercise induces a post-exercise decline in the number of circulating lymphocytes. The aim of the present study was to investigate whether strenuous exercise induces lymphocyte apoptosis and generation of reactive oxygen species. Eleven healthy male subjects exercised for 2.5 h on a treadmill. Apoptotic lymphocytes were defined by being annexin positive and 7-aminoactinomycin-D negative. Measurement of F(2)-isoprostanes was used as a marker of oxidant stress in vivo. An increase (60%, P<0.05) in the percentage of apoptotic circulating lymphocytes was found 2 h post-exercise, whereas the total number of apoptotic cells did not change in relation to exercise. The concentration of plasma F(2)-isoprostanes increased approximately 1.6-fold in response to exercise, but declined towards pre-exercise values within the 1st h of recovery. The plasma concentrations of adrenaline, noradrenaline and cortisol increased during exercise. In conclusion, the results of the present study demonstrate that even in a study design in which high levels of apoptosis-inducing factors are generated, such as cortisol and isoprostanes, lymphocyte apoptosis does not contribute to post-exercise lymphocytopenia.

Lymphopenia in dialysis patients: a preliminary study indicating a possible role of apoptosis

Lymphopenia is a common finding in dialysis patients. Since infection rate and mortality associated with infection are high in dialysis patients, lymphopenia may be one of the contributing factors. In the present study, we evaluated the mechanism responsible for lymphopenia in these patients. Lymphocytes isolated from dialysis patients showed increased apoptosis (p < 0.001) when compared to lymphocytes isolated from healthy subjects (healthy subjects, 0.5 +/- 0.2% vs. dialysis patients, 8.8 +/- 0.7% apoptotic cells/field). Sera from dialysis patients promoted lymphocyte apoptosis in a time- and dose-dependent manner. These sera also enhanced lymphocyte DNA fragmentation into multiple integers of 180 base pairs in the form of a ladder pattern. Cellulose acetate membranes promoted T cell apoptosis when compared to polysulfone membranes and to control. Cellulose acetate dialysis membranes also appear to promote lymphocyte FasL expression. Similarly, dialysis sera enhanced T cell Fas as well as FasL expression. Neither the cellulose acetate nor polysulfone membranes could induce FasL expression on B cells. Similarly, dialysis sera failed to induce FasL expression on B cells. On the other hand, anti-FasL antibodies attenuated dialysis sera-induced apoptosis in T as well as B cells. Interestingly, dialysis serum showed a 5-fold increase in FasL content when compared with control serum. These results suggest that dialysis-associated factors can induce autocrine death in T cells but the help of activated T cells is required to induce death in B cells.

BB rat lyp mutation and Type 1 diabetes

BioBreeding (BB) rats spontaneously develop an autoimmune diabetic syndrome similar to that observed in humans and NOD mice. One of the diabetes susceptibility loci maps to the lyp locus on chromosome 4. In this article we describe the consequences of the BB rat lyp mutation on T-cell homeostasis, repertoire and function, as well as its role in the pathogenesis of type I diabetes.

Il-7 and not stem cell factor reverses both the increase in apoptosis and the decline in thymopoiesis seen in aged mice

Thymic atrophy is an age-associated decline in commitment to the T cell lineage considered to be associated with defective TCR beta-chain rearrangement. Both IL-7 and stem cell factor (SCF) have dominant roles at this stage of triple negative (TN) thymocyte development. Because there is no age-associated decrease in the number of CD44(+)CD25(-)CD3(-)CD4(-)CD8(-) cells, this study investigated whether alterations in apoptosis within the TN pathway accounted for diminishing thymocyte numbers with age. Here we show significant age-associated increases in apoptotic TN thymocytes, specifically within CD44(+)CD25(+) and CD44(-)CD25(+) subpopulations, known to be the location of TCR beta-chain rearrangement. IL-7 added to TN cultures established from old mice significantly both reduces apoptosis and increases the percentage of live cells within CD44(+)CD25(+) and CD44(-)CD25(+) subpopulations after 24 h, with prosurvival effects remaining after 5 days. SCF failed to demonstrate prosurvival effects in old or young cultures, and IL-7 and SCF together did not improve upon IL-7 alone. IL-7R expression did not decline with age, ruling out the possibility that the age-associated increase in apoptosis was attributed to reduced IL-7R expression. Compared with PBS, treatment of old mice with IL-7 produced significant increases in live TN cells. By comparison, treatment with SCF failed to increase live TN numbers, and IL-7 and SCF together failed to significantly improve thymopoiesis above that shown by IL-7 alone. Thus, treatment with IL-7 alone can reverse the age-associated defect in TN thymocyte development revealed by in vitro studies to be located at the stages of TCR beta-chain rearrangement.

CD40 signaling replaces CD4+ lymphocytes and its blocking prevents chronic rejection of heart transplants

Chronic rejection remains the major obstacle to long term survival in heart transplant recipients. The cellular and molecular mechanisms that underlie chronic rejection are not known, and their discovery can form the basis of clinical intervention. Several investigators have suggested that the development of chronic rejection in solid organ transplants is dependent on help mediated by CD4(+) lymphocytes. Importantly, the mechanism through which help is provided has not been fully delineated in transplant rejection. Using a murine heterotopic heart transplant model without immunosuppression, this study defines the functional role of CD4(+) lymphocytes in chronic rejection. In an MHC class II-mismatched model, we demonstrate that chronic rejection was absolutely contingent on the presence of CD4(+) lymphocytes. Importantly, here we report that signaling through CD40 can replace the requirement of CD4(+) lymphocytes, demonstrated by the development of chronic rejection in CD4 knockout recipients treated with a CD40-activating mAb (FGK45). The return of rejection appears to be a CD8(+) lymphocyte-dependent process, noted by the absence of rejection in FGK45-treated recombinase-activated gene knockout (CD4(+) and CD8(+) lymphocyte-deficient) recipients. The CD40 signaling pathway works independently of B7-CD28 costimulation, as indicated by the development of severe chronic rejection in CD28 knockout recipients. Importantly, this study provides evidence that CD40 ligand-targeted therapies may prevent chronic rejection only in strain combinations where CD4(+) lymphocyte help is absolutely required.

Clinical associations of lymphopenia in elderly persons admitted to acute medical and psychiatric wards

Lymphopenia is a common finding in old people admitted to medical and psychiatric wards. We describe a pilot study of the clinical associations, and prognostic significance of lymphopenia in elderly persons admitted to acute medical and psychiatric wards. Consecutive patients admitted to acute medical and psychiatric wards were prospectively selected according to initial peripheral lymphocyte count (PLC) into lymphopenic (PLC < 1.0 X 10(9)/litre, n = 41), and non-lymphopenic (PLC > 1.5 x 10(9)/litre, n = 23). Results of routine haematological and biochemical investigations were recorded, as well as drug history and medical diagnoses. Anthropometric measurements, assessment of functional ability (Barthel ADL Index), and cognitive function (Mini-Mental State Examination) were then performed by investigators blind to lymphocyte status. Patients were contacted between 3 and 6 months following recruitment into the study. Lymphopenia was associated with functional ability as measured by a lower Barthel score (p = 0.004), and cognitive impairment as measured by the Mini-Mental State Examination (p = 0.02). No association was found with medical diagnostic groupings, drugs known to cause lymphopenia, nutritional status, or survival. Lymphopenia may be a significant marker of vulnerability, and a larger study is required to elucidate the veracity and mechanisms of lymphopenia-associated debility.

Leptin in the regulation of immunity, inflammation, and hematopoiesis

Leptin, the product of the ob gene, is a pleiotropic molecule that regulates food intake as well as metabolic and endocrine functions. Leptin also plays a regulatory role in immunity, inflammation, and hematopoiesis. Alterations in immune and inflammatory responses are present in leptin- or leptin-receptor-deficient animals, as well as during starvation and malnutrition, two conditions characterized by low levels of circulating leptin. Both leptin and its receptor share structural and functional similarities with the interleukin-6 family of cytokines. Leptin exerts proliferative and antiapoptotic activities in a variety of cell types, including T lymphocytes, leukemia cells, and hematopoietic progenitors. Leptin also affects cytokine production, the activation of monocytes/macrophages, wound healing, angiogenesis, and hematopoiesis. Moreover, leptin production is acutely increased during infection and inflammation. This review focuses on the role of leptin in the modulation of the innate immune response, inflammation, and hematopoiesis.

L-selectin-specific autoantibodies in murine lupus: possible involvement in abnormal homing and polarization of CD4+ T cell subsets

One notable functional abnormality in murine and human systemic lupus erythematosus (SLE) is the defect in the production of IL-2 in association with the deficit in naive CD4+ T cells. The mechanism is unknown, but one idea is that naturally occurring autoantibodies with specificities to the naive CD4+ T cell subpopulation are related to this event. We selected hybridoma monoclonal autoantibodies from SLE-prone (New Zealand Black (NZB) x New Zealand White (NZW))F1 mice that reacted with restricted populations of CD4+ T cells. One of these, H32, was specific for L-selectin, as determined by 1) distribution of Ag H32 on lymphoid cells similar to Mel-14, an epitope of L-selectin; 2) shedding of 80-kDa molecules with epitope H32 from the surface of lymph node cells coincidentally with Mel-14, when stimulated with phorbol ester; 3) cross-inhibitory activities on Ag binding between H32 and Mel-14; and 4) reactivity of H32 with recombinant mouse L-selectin. Pretreatment of 51Cr-labeled lymphocytes from BALB/c mice with H32 significantly inhibited their homing to lymph nodes in vivo. The BALB/c splenic H32+ CD4+ T cell subset produced few cytokines except IL-2, thus corresponding to naive ThP-type cells. This subset was markedly selectively depleted in aged (NZB x NZW)F1 mice. There was an age-associated increase in frequencies and titers of anti-L-selectin autoantibodies in sera from (NZB x NZW)F1 mice. Thus, abnormalities of naive CD4+ T cell subset, including IL-2 production in subjects with SLE, are at least partly attributed to the generation of autoantibodies to L-selectin.

High frequency apoptosis of recent thymic emigrants in the liver of lymphopenic diabetes-prone BioBreeding rats

Diabetes-prone (DP) BioBreeding (BB) rats develop spontaneous autoimmune diabetes. DP-BB thymocyte export is reduced, and most thymic emigrants disappear rapidly from peripheral lymphoid tissues. DP-BB rats are consequently lymphopenic and circulate severely reduced numbers of T cells. Peripheral T cells present are phenotypically immature (Thy1+) and appear activated. We hypothesized that DP-BB recent thymic emigrants have a shortened life span and disappear by apoptosis. The percentage of T cells with an alphabetaTCR(low) B220+ CD4- CD8- phenotype was increased in DP peripheral lymphoid tissues when compared with normal, nonlymphopenic diabetes-resistant (DR) BB rat tissues. There was no evidence of DNA fragmentation in freshly isolated DP- or DR-BB rat cells, but, after 24 h of culture, a higher proportion of DP- than DR-BB splenic T cells underwent apoptosis. We then tested the hypothesis that BB rat T cells with the alphabetaTCR(low) B220+ CD4- CD8- phenotype accumulate and undergo apoptosis in the liver. Such cells were observed undergoing apoptosis in both DP- and DR-BB rats, but comprised approximately 80% of intrahepatic T cells in DP vs approximately 20% in DR-BB rats. Most alphabetaTCR(low) B220+ CD4- CD8- cells in the liver were also Thy1+. The data suggest that T cell apoptosis in the DP-BB rat is underway in peripheral lymphoid tissues and is completed in the liver. Increased intrahepatic apoptosis of recent thymic emigrants appears in part responsible for lymphopenia in DP-BB rats and the concomitant predisposition of these animals to autoimmunity.

Nonmalignant disorders of lymphocytes

OBJECTIVE

To review the etiology, pathophysiology, clinical features, and laboratory findings in nonmalignant disorders of lymphocytes.

DATA SOURCES

Current literature.

STUDY SELECTION

Determined by author.

DATA EXTRACTION

Determined by author.

DATA SYNTHESIS

Assessing qualitative and quantitative changes in lymphocytes provides important information regarding immune reactions, disease conditions, and responses to therapy. Quantitative nonmalignant disorders encompass those conditions in which the total number of lymphocytes may be either increased (lymphocytosis) or decreased (lymphocytopenia). Frequently encountered disorders with a lymphocytosis include infectious mononucleosis and cytomegalovirus infection. Lymphocytopenia is not detected as often or as easily in the clinical laboratory, but may be induced by several causes such as stress, certain types of therapy, nutrient deficiencies, or premature destruction of lymphocytes as occurs in acquired immunodeficiency syndrome. Clinical and laboratory findings provide significant clues in defining the etiology of a nonmalignant disorder of lymphocytes.

CONCLUSION

Disorders of lymphocytes include both benign and malignant quantitative and qualitative variations. A reactive lymphocytosis is commonly associated with many viral and certain bacterial infections. The clinical laboratory plays an important role in differentiating reactive and malignant lymphoproliferative processes. Benign lymphocytopenia, although not a frequent finding, must also be characterized by the laboratory.

Intestinal lymphangiectasia: value of Tc-99m dextran lymphoscintigraphy

Intestinal lymphangiectasia is a common cause of protein-losing enteropathy characterized by diarrhea, generalized edema, enteric protein loss, hypoproteinemia, and lymphopenia. Diagnosis is based on demonstration of enteric protein loss and characteristic small bowel mucosal histology. Various imaging modalities including barium studies, computed tomography, and lymphangiography have had limited clinical use. The authors report a case of intestinal lymphangiectasia in which Tc-99m dextran lymphoscintigraphy played a significant role in the patient management.

Is presentation of bacteremia in the elderly the same as in younger patients?

OBJECTIVE

To compare the presentation of bacteremia in young and elderly patients.

PATIENTS AND METHODS

Seventy-one elderly (mean age 80.4 years) and 34 younger inpatients (mean age 45.7 years) with bacteremia were prospectively studied. These were compared with a control group of 187 geriatric patients (mean age 81.3 years) with clinical signs of bacteremia but in whom blood cultures were negative. Bacteremia was defined as one or more positive blood cultures showing a pathogenic bacteria in patients with clinical signs of bacteremia. In all 105 patients with bacteremia, 16 common clinical or biological signs of the disease were immediately investigated after blood culture. Patients were classified into three groups: elder patients and young patients with bacteremia and elderly patients without bacteremia.

RESULTS

Only three clinical findings of the 16 studied were found in at least 70% of the bacteremic elderly patients: fever, increased erythrocyte sedimentation rate, and a clinical indication of the source of infection. These three signs were found statistically more often in bacteremic elderly compared with nonbacteremic elderly patients (P < 0.01). Seven other signs (hypothermia, altered mental state, leukopenia, and lymphopenia) had a specificity above 80%. On a logistic regression analysis, four variables were significantly and independently associated with bacteremia in the elderly: rapid onset of infection (defined as a period < or = 48 hours between the earliest manifestation of bacteremia and the time of blood blood sample), fever, altered general state, and clinical indication of the source of infection. Younger infected patients had more chills, sweating, alter general state, altered mental state or lymphopenia than did the bacteremic elderly patients. Bacteremic elderly patients had statistically few symptoms than the young infected patients (P < 0.001).

CONCLUSIONS

In elderly patients with early stage bacteremia, most of the signs or symptoms that are considered typical in the literature appear irregularly. None appeared pathognomonic. Elderly patients with bacteremia had fewer signs or symptoms than younger infected patients.

Bone mineral metabolism in T lymphocyte-deficient and -replete strains of rat

The immune and skeletal systems are known to interact. We have repeatedly shown that in contrast to in vitro data, the administration of T lymphocyte immunosuppressants, such as cyclosporin A, leads to an increase in bone resorption and a high turnover osteopenia. The purpose of this study was to characterize the bone metabolism of the T lymphocyte deficient Rowett athymic homozygous (rnu/rnu) nude rat. We wished to determine whether these rats share the bone abnormalities of cyclosporin A-treated rats. Eleven 10-week-old Sprague-Dawley rats and 12 similarly aged nude rats were studied over a 4-week period. Metaphyseal cancellous bone histomorphometry was similar in the two groups of rats and only differed with regard to percentage eroded perimeter (lower in nude rats, p = 0.0008) and longitudinal growth rate (49% lower in nude rats, p < 0.001). The nude rats had less body mass (p < 0.001) but nevertheless gained the same percentage of their body weight over the study period. The athymic rats had lower levels of serum, 1,25-dihydroxyvitamin D (p < 0.014) and serum osteocalcin(p < 0.009), and at the age of 14 weeks the nude rats had lower concentrations of serum creatinine (p = 0.001) and blood ionized calcium (p = 0.0002), yet serum PTH was similar throughout. RNA isolated from the contralateral tibias revealed that the nude group had lower steady-state levels of osteocalcin mRNA despite similar rates of bone formation. In its entirety, the data suggest that T cell deficiency per se is not necessarily associated with high turnover osteopenia.

Hematological effects of inhaled plutonium dioxide in beagles

A life-span study indicated that plutonium activity in the thoracic lymph nodes is a contributor to development of lymphopenia in beagles exposed to 239PuO2. Significant lymphopenia was found in 67 (58%) beagles given a single nose-only exposure to 239PuO2 to result in mean initial lung depositions ranging from 0.69 to 213.3 kBq. Lymphoid atrophy and sclerosis of the thoracic lymph nodes and lymphopenia were observed in exposure-level groups with initial lung depositions > or = 2.5 kBq. Those dogs with final plutonium concentrations in the thoracic lymph nodes > or = 0.4 kBq/g and dose rates > or = 0.01 Gy/day developed lymphopenia. Marked differences existed between chronically lymphopenic dogs and intermittently lymphopenic dogs with regard to initial lung deposition, time to lymphopenic events and absolute lymphocyte concentrations. Linear regression analysis revealed moderate correlation between reduction in lymphocyte values and initial lung deposition, in both magnitude and time of appearance after exposure. Cumulative dose and dose rate appeared to act together to produce initial effects on lymphocyte populations, while dose rate alone appeared to be responsible for the maintenance and subsequent cycles of lymphopenia seen over the life span. No primary tumors were associated with the thoracic lymph nodes in this study, although 70% of the lymphopenic dogs developed lung tumors.

Prognostic significance of lymph node reactivity in patients with laryngeal carcinoma

Apart from the presence or absence of metastases in patients with laryngeal carcinoma, there are changes of reactivity in cervical lymph nodes that are seen histologically as nonspecific reactive lymphadenitis. These changes are morphological manifestations of the regional lymphatic system reactivity in relation to tumor, and their presence may be of prognostic value. To test this hypothesis, 45 patients with laryngeal carcinoma were examined for the evidence of node reactivity. The classification applied by Tsakraklides et al. was used, defining patterns of lymphocyte predominance, germinal center appearance (indicating lymph node stimulation) and whether or not lymphocyte depletion had occurred. The presence of node reactivity was compared with long-term (5-year) survivals in the group of patients studied. By applying statistical analysis it was found that lymph node stimulation was a favorable prognostic factor, while its absence worsened prognosis.

Systemic lupus erythematosus in men: a multivariate analysis of gender differences in clinical manifestations

The marked gender influence on the occurrence of systemic lupus erythematosus (SLE) indicates that genetic and hormonal factors may be important in the etiology of this illness. However, few differences in clinical manifestations between males and females have been reported. To further investigate gender differences in SLE, the prevalence of 23 clinical manifestations of SLE were compared in a cohort of 62 men and 299 women. After adjusting for differences in age, race, and duration of followup, men were found to more commonly have seizures (odds ratio = 1.65; 95% confidence interval = 1.09, 2.49), and showed a trend to progress to renal failure more often (odds ratio = 1.40; 95% confidence interval = 0.96, 2.03) than women. Gender differences were not evident for the remaining 21 clinical features. The clinical similarity between men and women with SLE represents a circumstance in which the use of clinically defined patient subsets does not appear to facilitate the investigation of potential pathogenetic or etiologic factors.

Increased periodontal bone loss in temporarily B lymphocyte-deficient rats

In order to study the role of T lymphocytes and B lymphocytes in the development of marginal periodontitis, experiments were performed on specific-pathogen-free (SPF) rats with various immunologic profiles. The study comprised nude (congenitally T lymphocyte-deficient), thymus-grafted nude (T-lymphocyte reconstituted), anti-mu treated (temporarily B lymphocyte-deficient), and normal rats. When they were 5 to 9 weeks old, some of the rats were inoculated with Actinomyces viscosus. Bacteroides gingivalis and a strain of oral spirochetes; 90 days later they were killed. A. viscosus and B. gingivalis colonized readily, but the spirochete strain could not be established permanently in the oral cavity of the rats, 95% of the inoculated rats raised serum IgG or IgM antibody against one or more of the microorganisms; nude rats tended to raise less antibody than the three other experimental groups. Inoculated rats had significantly less periodontal bone support than controls. Anti-mu treated inoculated rats had significantly less periodontal bone support than nude and normal rats, whereas no difference was found between normal, nude, and thymus-grafted rats. It is concluded that permanent T-lymphocyte deficiency did not interfere with the development of periodontal disease in this model, whereas a temporary and moderate reduction in B-lymphocyte numbers seemed to predispose for aggravation of periodontal bone loss.

Muscle strength, endurance and recovery in the post-infection fatigue syndrome

A test of muscle strength and "fatiguability" was administered to 20 normal subjects and 20 patients suffering from post-infection fatigue syndrome. Maximal isometric torque for the elbow flexors was measured before, during and after an endurance sequence of 18 maximal static contractions (10 s duration, 10 s rest interval). The maximal isometric strength was not significantly different between the patient and control groups. The relative torque produced at the end of the series of 18 static contractions did not differ significantly between patients and normal subjects. In the patients with post-infection fatigue syndrome there was impairment of the recovery of peak torque at 10 minutes after the endurance sequence (p less than 0.02). The prominent subjective complaint of muscle fatigue in patients with post-infection fatigue syndrome contrasts with the relatively normal behaviour of their muscles during a controlled test of fatigue. The syndrome may include a disordered perception of achieved force and exertion.

The contributions of adrenal hormones, hemodynamic factors, and the endotoxin-related stress reaction to stable prostaglandin analog-induced peripheral lymphopenia and neutrophilia

Stable prostaglandin analogs are known to induce lymphopenia and neutrophilia in a dose-dependent fashion after subcutaneous injection in rats. The purpose of the present investigation is to determine whether the prostaglandin-induced changes in circulating leukocytes might be secondary to hypotension with the ensuing release of adrenal hormones. The adrenal medullary catecholamine epinephrine was found to induce neutrophilia in both intact and adrenalectomized rats, and the glucocorticosteroid analog dexamethasone induced a profound lymphopenia in rats as reported by previous investigators. A stable analog of PGF2 alpha (15-S-15-methyl PGF2 alpha; M-PGF2 alpha) at the dose of 1 mg/kg induced marked systemic hypotension 1 h after injection, with lymphopenia and neutrophilia 6 h after injection. The non-prostanoid hypotensive agent captopril, at a dose of 63 mg/kg, induced a hypotension of similar magnitude and kinetics to that induced by prostaglandin. Captopril also induced lymphopenia and neutrophilia at 6 h, although the neutrophilia was of lesser magnitude than that induced by prostaglandins. The prostaglandin-induced lymphopenia was found to be mediated, at least in part, by the hypotension-induced release of adrenal hormones, as evidenced by the abrogation of lymphopenia in prostaglandin-treated adrenalectomized rats. Captopril-treated adrenalectomized rats, however, did develop a significant lymphopenia, suggesting that hypotension can result in lymphopenia even in adrenalectomized rats. The M-PGF2 alpha-induced neutrophilia in adrenalectomized rats, by comparison to captopril-induced neutrophilia in adrenalectomized rats, was greater than the neutrophilia expected as the result of hypotension alone. Indeed, the M-PGF2 alpha-induced neutrophilia in adrenalectomized rats was greater than the captopril-induced neutrophilia in sham-adrenalectomized rats. Thus, a portion of the neutrophilia induced by M-PGF2 alpha in intact rats may be mediated through adrenal-independent, hemodynamic-independent mechanisms. The possibility that M-PGF2 alpha might be inducing neutrophilia via an endotoxin-like stress reaction was investigated by examining changes in circulating white blood cells in intact and adrenalectomized C3H/HeN (endotoxin-sensitive) and C3H/HeJ (endotoxin-resistant) mice after prostaglandin administration. No quantitative differences in the prostaglandin-induced neutrophilia were noted in C3H/HeJ mice as compared to the C3H/HeN mice.(ABSTRACT TRUNCATED AT 400 WORDS)

Kinetics and mechanisms of recombinant human interleukin 1 and tumor necrosis factor-alpha-induced changes in circulating numbers of neutrophils and lymphocytes

Human recombinant interleukins 1 alpha and 1 beta (rIL-1 alpha and -1 beta) both induced monophasic peripheral neutrophilia and lymphopenia in Lewis rats 1.5 hr after i.v. injection. The kinetics of rIL-1 alpha- and -1 beta-induced neutrophilia were similar to those induced by human monocyte-derived IL-1, IL-1 alpha, and IL-1 beta, and the peripheral neutrophilia was accompanied by a marked decrease in marrow neutrophils. Arachidonic acid metabolites are implicated as biochemical intermediates in the production of the neutrophilia but not lymphopenia, since indomethacin and dexamethasone both completely abrogated IL-1-induced neutrophilia but did not affect the IL-1-induced lymphopenia. Acetylsalicylic acid, a cyclooxygenase inhibitor, did not inhibit IL-1-induced neutrophilia, suggesting that products of the lipoxygenase rather than the cyclooxygenase pathway of arachidonate metabolism may contribute to the neutrophilia. Human recombinant tumor necrosis factor-alpha (rTNF) administered i.v. to Lewis rats induced peripheral neutropenia, two peaks of neutrophilia, and lymphopenia. A wide range of doses of rTNF resulted in an initial neutropenia at 0.5 hr after injection followed by a first peak of neutrophilia at 1.5 hr and a second peak of neutrophilia at 6 hr. The initial neutropenia and the first peak of neutrophilia were not inhibited by pretreatment of rats with dexamethasone, indomethacin, or aspirin. The second peak of neutrophilia was inhibited by both dexamethasone and indomethacin, but was not at all inhibited by aspirin, suggesting that the second peak of neutrophilia is mediated by the release of endogenous cytokines, especially by IL-1, since exogenous IL-1-induced neutrophilia is also completely inhibited by dexamethasone and indomethacin but not by aspirin. The TNF-induced peripheral neutrophilia is also accompanied by a significant depletion of bone marrow neutrophils, indicating that the source of increased circulating neutrophils is, at least in part, via recruitment of marrow neutrophils. Systemic blood pressure was not affected by IL-1 or rTNF at the dosages employed, showing that the changes in circulating leukocyte subsets were not attributable to hemodynamic changes nor to the hemodynamic change-related release of adrenal hormones. Adrenalectomy did not alter the IL-1- or rTNF-induced neutrophilia or lymphopenia, also demonstrating that neither monokine mediates its hematologic effects on peripheral blood leukocytes via the release of adrenal hormones.(ABSTRACT TRUNCATED AT 400 WORDS)