R-ketorolac ameliorates cancer-associated cachexia and prolongs survival of tumour-bearing mice

BACKGROUND

Cancer-associated cachexia (CAC) is a debilitating syndrome associated with poor quality of life and reduced life expectancy of cancer patients. CAC is characterized by unintended body weight reduction due to muscle and adipose tissue loss. A major hallmark of CAC is systemic inflammation. Several non-steroidal anti-inflammatory drugs (NSAIDs) have been suggested for CAC treatment, yet no single medication has proven reliable. R-ketorolac (RK) is the R-enantiomer of a commonly used NSAID. The effect of RK on CAC has not yet been evaluated.

METHODS

Ten- to 11-week-old mice were inoculated with C26 or CHX207 cancer cells or vehicle control (phosphate-buffered saline [PBS]). After cachexia onset, 2 mg/kg RK or PBS was administered daily by oral gavage. Body weight, food intake and tumour size were continuously measured. At study endpoints, blood was drawn, mice were sacrificed and tissues were excised. Immune cell abundance was analysed using a Cytek® Aurora spectral flow cytometer. Cyclooxygenase (COX) activity was determined in lung homogenates using a fluorometric kit. Muscle tissues were analysed for mRNA and protein expression by quantitative real-time PCR and western blotting analysis, respectively. Muscle fibre size was determined on histological slides after haematoxylin/eosin staining.

RESULTS

Ten-day survival rate of C26-bearing animals was 10% while RK treatment resulted in a 100% survival rate (P = 0.0009). Chemotherapy resulted in a 10% survival rate 14 days after treatment initiation, but all mice survived upon co-medication with RK and cyclophosphamide (P = 0.0001). Increased survival was associated with a protection from body weight loss in C26 (-0.61 ± 1.82 vs. -4.48 ± 2.0 g, P = 0.0004) and CHX207 (-0.49 ± 0.33 vs. -2.49 ± 0.93 g, P = 0.0003) tumour-bearing mice treated with RK, compared with untreated mice. RK ameliorated musculus quadriceps (-1.7 ± 7.1% vs. -27.8 ± 8.3%, P = 0.0007) and gonadal white adipose tissue (-18.8 ± 49% vs. -69 ± 15.6%, P = 0.094) loss in tumour-bearing mice, compared with untreated mice. Mechanistically, RK reduced circulating interleukin-6 (IL-6) concentrations from 334 ± 151 to 164 ± 123 pg/mL (P = 0.047) in C26 and from 93 ± 39 to 35 ± 6 pg/mL (P = 0.0053) in CHX207 tumour-bearing mice. Moreover, RK protected mice from cancer-induced T-lymphopenia (+1.8 ± 42% vs. -49.2 ± 12.1% in treated vs. untreated mice, respectively). RK was ineffective in ameliorating CAC in thymus-deficient nude mice, indicating that the beneficial effect of RK depends on T-cells.

CONCLUSIONS

RK improved T-lymphopenia and decreased systemic IL-6 concentrations, resulting in alleviation of cachexia and increased survival of cachexigenic tumour-bearing mice, even under chemotherapy and independent of COX inhibition. Considering its potential, we propose that the use of RK should be investigated in patients suffering from CAC.

Improvements in quality of life over 2 years with cladribine tablets in people with relapsing multiple sclerosis: The CLARIFY-MS study

BACKGROUND

Multiple sclerosis (MS) negatively affects health-related quality of life (HRQoL).

OBJECTIVE

To evaluate HRQoL in people with highly active relapsing MS treated with cladribine tablets (CladT; 3.5 mg/kg cumulative dose over 2 years) in CLARIFY-MS.

METHODS

Changes in the MS quality of life (MSQoL)-54 scores were analysed using a repeated mixed-effects linear model. Subgroup analyses were performed for participants who were pretreatment-naïve and those pretreated with disease-modifying therapies (DMTs) before initiating CladT. Safety and tolerability of CladT were also assessed.

RESULTS

MSQoL-54 physical (mean change = 4.86; 95% confidence interval (CI) = 3.18, 6.53) and mental health (4.80; 95% CI = 3.13, 6.46) composite scores (primary endpoints) showed significant improvement at Month 24 versus Baseline (p < 0.0001). Changes in the MSQoL-54 scores were consistent across the pretreatment-naïve and DMT-pretreated subgroups. No new severe or opportunistic infections occurred. Most post-baseline lymphopenia events were Grade 1-2 in severity. Transient Grade-3 lymphopenia was observed in 19.7% (95/482) of participants. Grade-4 lymphopenia was not observed.

CONCLUSIONS

CladT treatment significantly improved the mean MSQoL-54 physical and mental health composite scores over 2 years. CladT efficacy in HRQoL, relapse rates and Expanded Disability Status Scale scores demonstrates its multidimensional effects in MS treatment.

The effect of radioiodine therapy on blood cell count in patients with differentiated thyroid cancer

PURPOSE

This study aimed to investigate the long-term effects of radioiodine treatment (RAI) on blood cell counts in patients with differentiated thyroid cancer (DTC) and to describe the characteristics of patients at high risk for blood cell count abnormalities.

METHODS

The study included patients with DTC who underwent RAI treatment between 2007 and 2017. Patients with regular complete blood counts for at least 5 years were included, while those with diseases or treatments that could influence blood count parameters were excluded. Blood cell count abnormalities were defined according to the Common Terminology Criteria for Adverse Events version 5.0, and factors influencing these abnormalities were examined.

RESULTS

A total of 225 patients were analyzed. The mean age at diagnosis was 45.8 ± 13.9 years, and 76.5% of patients were female. In the first year after RAI, leukocyte, neutrophil, and lymphocyte counts were significantly reduced compared with baseline values. The leukocyte and neutrophil counts returned to baseline values by the third year, while the decrease in lymphocytes continued until the fifth year. Blood cell count abnormalities developed in 16 patients (7.1%) within the first year after RAI. Risk factors for blood cell count abnormalities within the first year after RAI included male sex, older age, T4, N1, and M1 disease, as well as higher RAI doses. In logistic regression analysis, only RAI dose remained independently associated with blood cell count abnormalities.

CONCLUSION

These results suggest an association between RAI dose and blood cell count abnormalities, characterized by mild lymphopenia, and indicate that the risk of mild lymphopenia persists over time. Careful consideration should be given when planning high-dose RAI for patients at a high risk of blood cell count abnormalities, such as males with metastatic disease and of advanced age.

Impact of Radiation Dose to Circulating Immune Cells on Tumor Control and Survival in Esophageal Cancer

Background: The immune system is well known to exert tumor immunosurveillance effects, and that immune cells circulating in the peripheral blood affect tumor prognosis. The study investigated the effect of estimated dose of radiation on circulating immune cells (EDRIC) and tumor control for esophageal cancer patients treated with concurrent chemo-radiotherapy. Materials and Methods: A total of 146 esophageal cancer patients treated with radiotherapy between January 2016 and June 2020 were retrospectively identified. We determined EDRIC, known prognostic factors, and the association of these factors with progression-free survival (PFS) and overall survival (OS). Results: The median follow-up was 17.9 months (2.7-60.4 months). The 3-year OS was 39.2%. Severe post-treatment lymphopenia was observed in 84.2% of patients. A negative correlation between EDRIC and absolute lymphocyte count was found (r = -0.679; p < 0.001). Patients with EDRIC ≥10.3 Gy were more likely to demonstrate grade 4 lymphopenia (55.2% vs. 4.5%; p < 0.001). Patients with grade 4 lymphopenia had a worse OS and PFS. On multivariate analysis, EDRIC was independently associated with OS (hazard ratio [HR], 1.142; p = 0.016) and PFS (HR, 1.121; p = 0.019). Conclusions: EDRIC can predict lymphocyte reduction and poor prognosis for esophageal cancer patients treated with radiotherapy.

Cladribine tablets for highly active relapsing-remitting multiple sclerosis in Poland: a real-world, multi-centre, retrospective, cohort study during the COVID-19 pandemic

INTRODUCTION

Treatment with cladribine tablets is indicated in highly active relapsing-remitting multiple sclerosis (RRMS). Cladribine tablets proved safe and effective in the pivotal CLARITY trial, but that trial included primarily treatment-naïve patients. In clinical practice however, cladribine tablets are often given to patients who have failed other treatments. Therefore, this study investigated the real-world safety and efficacy of cladribine tablets.

MATERIAL AND METHODS

We gathered data from nine MS clinical centres across Poland for patients with RRMS who started treatment with cladribine tablets from December 2019 to June 2022.

RESULTS

We enrolled 140 patients, with follow-up data available for 136 in year 1 and for 66 in year 2. At baseline, the mean age was 35.6 years, mean disease duration was 7.3 years, median EDSS score was 2.5, and 94% of patients were treatment- -experienced. Thirty-nine patients (27.9%) had undergone COVID-19, and 94 (67.1%) were vaccinated against COVID-19. The annualised relapse rate (ARR) decreased from 1.49 at baseline to 0.33 in year 1 (p < 0.001) and to 0.25 in year 2 (p < 0.001). The percentage of relapse-free patients increased from 11.5% at baseline to 70.2% in year 1 and 82.1% in year 2. The percentage of patients with active lesions decreased from 91.4% at baseline to 36.2% in year 1 and 18.2% in year 2. EDSS score remained stable or improved in 83.7% of patients in year 1 and 89.6% in year 2. No evidence of disease activity (NEDA-3) was achieved in 42.7% of patients in year 1 and 66.7% in year 2. Only one patient (0.72%) had grade 4 lymphopenia and 21 (15.1%) had grade 3 lymphopenia. Varicella zoster virus infections occurred in three patients. Eight patients discontinued treatment with cladribine: five due to inefficacy, one due to lymphopenia, and two due to a personal decision.

CONCLUSIONS

Cladribine tablets proved safe and effective in a real-world cohort of treatment-experienced patients. However, the efficacy measures improved to a lesser extent in our cohort than in the pivotal clinical trial, which is probably due to a higher proportion of treatment-experienced patients in our cohort.

Effect of rituximab on immune status in children with mature B-cell non-Hodgkin lymphoma: a prespecified secondary analysis of the Inter-B-NHL Ritux 2010 trial

BACKGROUND

Survival of children and adolescents with high-risk, mature B-cell non-Hodgkin lymphoma is improved by the addition of rituximab to chemotherapy. The effect of rituximab on immune reconstitution after therapy has not been well described. Herein, we evaluate the immune effects of the addition of rituximab to intensive chemotherapy, a prespecified secondary aim of the Inter-B-NHL Ritux 2010 trial.

METHODS

The Inter-B-NHL Ritux 2010 trial was an international, open-label, randomised, phase 3 trial in children (age 6 months to 18 years) with high-risk, mature B-cell non-Hodgkin lymphoma, comparing chemotherapy alone or chemotherapy with rituximab. Measures of immune status were completed at baseline, 1 month from the end of treatment, and 1 year from the start of therapy, and yearly thereafter until normalised. For this secondary analysis, we report on the proportions of patients with low lymphocyte counts and immunoglobulin concentrations at these timepoints with total lymphocyte count, B-cell count, and IgG concentration as the main endpoints. Other endpoints of interest included exposure to immunoglobulin replacement therapy and vaccine serologies. The population assessed for immune endpoints was the eligible per-protocol population with at least one immune parameter at one timepoint. Comparisons of immune status were made between the randomised treatment groups. Safety in the post-therapy period was assessed in the population eligible for the immunity study who were followed up at least 3 months after the end of treatment and without cancer-related events. The Inter-B-NHL Ritux 2010 study was registered with ClinicalTrials.gov, NCT01516580; status completed, with analyses of secondary aims ongoing.

FINDINGS

From Dec 19, 2011, to June 13, 2017, 421 patients (344 [82%] boys and 77 [18%] girls; mean age was 8·8 years [SD 4·1]) were enrolled and had immune data at baseline during follow-up, or both. The study population included randomly assigned patients (n=289) and a non-randomised cohort enrolled after the planned interim analysis (n=132). At baseline, 99 (34%) of 290 patients with available data (excluding patients with bone marrow disease with peripheral blast cells) had lymphopenia, and 178 (48%) of 368 had hypogammaglobulinemia. 1 month from the end of therapy, patients who received chemotherapy with rituximab were more likely than those who received chemotherapy alone to have lymphopenia (86 [81%] of 106 vs 53 (60%) of 89, odds ratio [OR] 2·92 [95% CI 1·53-5·57], p=0·0011), B-cell lymphopenia (72 [96%] of 75 vs 36 [64%] of 56, OR 13·33 [3·71-47·84], p<0·0001), and hypogammaglobulinemia (67 [71%] of 95 vs 37 [47%] of 79, OR 2·72 [1·45-5·07], p=0·0017). Differences remained at 1 year for hypogammaglobulinemia only (52 [55%] of 94 vs 16 [25%] of 63, OR 3·64 [1·81-7·31], p=0·0003). Patients in the chemotherapy with rituximab group were more likely than those in the chemotherapy group to receive immunoglobulin replacement (26 [16%] 164 vs nine [7%] of 158, hazard ratio [HR] 2·63 [95% CI 1·23-5·62], p=0·010), mainly due to low immunoglobulin concentration. In the combined treatment groups, including non-randomly assigned patients, the proportion of patients who had loss of protective serologies to a vaccine preventable infection varied from four (9%) of 47 for polio to 21 (42%) of 50 for Streptococcus pneumoniae (pneumococcus). One patient (chemotherapy with rituximab group) had a life-threatening infectious event of polymicrobial bacterial sepsis reported 2 months after the final chemotherapy administration.

INTERPRETATION

Children with high-risk mature B-cell non-Hodgkin lymphoma receiving chemotherapy with rituximab were at risk of prolonged hypogammaglobulinemia, although severe infections were rare. Strategies for immunoglobulin replacement and revaccination are needed.

FUNDING

Clinical Research Hospital Program of the French Ministry of Health, Cancer Research UK, National Institute for Health Research Clinical Research Network in England, Children's Cancer Foundation Hong Kong, US National Cancer Institute, F Hoffmann-La Roche.

Prognostic significance of therapy-induced myelosuppression in newly diagnosed glioblastoma

BACKGROUND

Myelosuppression is the major toxicity encountered during temozolomide chemoradiotherapy for newly diagnosed glioblastoma.

METHODS

We assessed the association of myelosuppression (neutropenia, thrombocytopenia, anemia, and lymphopenia) during temozolomide chemoradiotherapy alone or in combination with experimental agents with progression-free survival (PFS) or overall survival (OS) in 2073 patients with newly diagnosed glioblastoma enrolled into five clinical trials: CENTRIC, CORE, EORTC 26082, AVAglio, and EORTC 26981. A landmark Cox model was used. For each primary association analysis, a significance level of 1.7% was used.

RESULTS

Lower neutrophil counts at baseline were associated with better PFS (P = .011) and OS (P < .001), independently of steroid intake. Females experienced uniformly more myelotoxicity than males. Lymphopenia during concomitant chemoradiotherapy was associated with OS (P = .009): low-grade (1-2) lymphopenia might be associated with superior OS (HR 0.78, 98.3% CI 0.58-1.06), whereas high-grade (3-4) lymphopenia might be associated with inferior OS (HR 1.08, 98.3% CI 0.75-1.54). There were no associations of altered hematological parameters during concomitant chemoradiotherapy with PFS. During maintenance chemoradiotherapy, no significant association was found between any parameter of myelosuppression and PFS or OS, although exploratory analysis at 5% significance level indicated that either mild-to-moderate (HR 0.76, 95% CI 0.62-0.93) or high-grade lymphopenia (HR 0.65, 95% CI 0.46-0.92) was associated with superior OS (P = .013), but not PFS.

CONCLUSIONS

The association of higher neutrophil counts at baseline with inferior PFS and OS requires further prospective evaluation. The link of therapy-induced lymphopenia to better outcome may guide the design for immunotherapy trials in newly diagnosed glioblastoma.

Immune dysregulation and system pathology in COVID-19

The coronavirus disease 19 (COVID-19) caused by the novel coronavirus known as SARS-CoV-2 has caused a global public health crisis. As of 7 January 2021, 87,640,402 confirmed cases and 1,891,692 mortalities have been reported worldwide. Studies focusing on the epidemiological and clinical characteristics of COVID-19 patients have suggested a dysregulated immune response characterized by lymphopenia and cytokine storm in these patients. The exaggerated immune response induced by the cytokine storm causes septic shock, acute respiratory distress syndrome (ARDS), and/or multiple organs failure, which increases the fatality rate of patients with SARS-CoV-2 infection. Herein, we review the recent research progress on epidemiology, clinical features, and system pathology in COVID-19. Moreover, we summarized the recent therapeutic strategies, which are either approved, under clinical trial, and/or under investigation by the local or global health authorities. We assume that treatments should focus on the use of antiviral drugs in combination with immunomodulators as well as treatment of the underlying comorbidities.

Efficacy and safety assessment of severe COVID-19 patients with Chinese medicine: A retrospective case series study at early stage of the COVID-19 epidemic in Wuhan, China

ETHNOPHARMACOLOGICAL RELEVANCE

The coronavirus disease 2019 (COVID-19) has formed a global pandemic since late 2019. Benefitting from the application experience of Chinese Medicine (CM) for influenza and SARS, CM has been used to save patients at the early stage of COVID-19 outbreak in China.

AIM OF THE STUDY

In order to evaluate the efficacy and safety of CM, and compare with Western Medicine (WM) for COVID-19, we conducted a retrospective case series study based on the patients in Wuhan Jinyintan Hospital, Wuhan, China.

METHODS

The inclusion and exclusion criteria of data extraction were set for this retrospective study. All patients who were admitted by the Wuhan Jinyintan Hospital between January 17th and February 25th 2020 were considered. In addition, patients enrolled met the severe defined by the guidelines released by the National Health Commission of the People's Republic of China. In these cases included in the study, CM or WM treatment was selected according to the wishes of the patients at the beginning of hospitalization. The patients in CM group were treated with Huashi Baidu granule (137 g po, bid) combined with the injections of Xiyanping (100 mg iv, bid), Xuebijing (100 ml iv, bid) and Shenmai (60 ml iv, qd) according to the syndrome of epidemic toxin blocking the lung in the theory of Traditional Chinese Medicine. The WM group received antiviral therapy (including abidor capsule 0.2 g po, tid; Lopinavir-Ritonavir tablets, 500 mg po, bid), antibiotics (such as cefoperazone 2 g iv, bid; moxifloxacin hydrochloride tablets, 0.4 g po, qd) or corticosteroid therapy (such as methylprednisolone succinate sodium 40 mg iv, qd; prednisone, 30 mg po, qd). In addition, patients in both groups received routine supportive treatment, including oxygen inhalation, symptomatic therapy, and/or human intravenous immunoglobulin, and/or serum albumin, and treatment for underlying diseases. The clinical outcomes were evaluated based on changes related with clinical manifestations, computer tomography (CT) scan images, and laboratory examinations before and after the treatment.

RESULTS

55 severe COVID-19 patients, with 23 in CM group and 32 in WM group, were included for analyzed. There was no case of death, being transferred to ICU, or receiving invasive mechanical ventilation in two groups during hospitalization. The median time of SARS-CoV-2 RNA clearance in CM and WM group were 12 days and 15.5 days respectively, the ratio of nucleic acid negative conversion of CM group at different follow-up time points was significantly higher than that of WM group (HR: 2.281, P = 0.018). Further, the chest CT imaging showed more widely lung lesion opacity absorbed in the CM group. The high sensitivity C-reactive protein and serum ferritin decreased significantly in the CM group (P<0.05). There was no significant difference in adverse events in terms of liver function and renal function between the two groups.

CONCLUSION

Based on this retrospective analysis from Wuhan Jinyintan Hospital, CM has better effects in SARS-CoV-2 RNA clearance, promoting lung lesion opacity absorbed and reducing inflammation in severe COVID-19 patients, which is effective and safe therapy for treating severe COVID-19 and reducing mortality.

Antibiotic administration exacerbates acute graft vs. host disease-induced bone marrow and spleen damage in lymphopenic mice

Background

Hematopoietic stem cell transplantation is a potential cure for certain life-threatening malignant and nonmalignant diseases. However, experimental and clinical studies have demonstrated that pre-transplant myeloablative conditioning damages the gut leading to translocation of intestinal bacteria and the development of acute graft vs. host disease (aGVHD). The overall objective of this study was to determine whether administration of broad spectrum antibiotics (Abx) affects the onset and/or severity of aGVHD in lymphopenic mice that were not subjected to toxic, pre-transplant conditioning.

Results

We found that treatment of NK cell-depleted recombination activating gene-1-deficient (-NK/RAG) recipients with an Abx cocktail containing vancomycin and neomycin for 7 days prior to and 4 weeks following adoptive transfer of allogeneic CD4⁺ T cells, exacerbated the development of aGVHD-induced BM failure and spleen damage when compared to untreated–NK/RAG recipients engrafted with syngeneic or allogeneic T cells. Abx-treated mice exhibited severe anemia and monocytopenia as well as marked reductions in BM- and spleen-residing immune cells. Blinded histopathological analysis confirmed that Abx-treated mice engrafted with allogeneic T cells suffered significantly more damage to the BM and spleen than did untreated mice engrafted with allogeneic T cells. Abx-induced exacerbation of BM and spleen damage correlated with a dramatic reduction in fecal bacterial diversity, marked loss of anaerobic bacteria and remarkable expansion of potentially pathogenic bacteria.

Conclusions

We conclude that continuous Abx treatment may aggravate aGVHD-induced tissue damage by reducing short chain fatty acid-producing anaerobes (e.g. Clostridium, Blautia) and/or by promoting the expansion of pathobionts (e.g. Akkermansia) and opportunistic pathogens (Cronobacter).

Morpholino Analogues of Fingolimod as Novel and Selective S1P1 Ligands with In Vivo Efficacy in a Mouse Model of Experimental Antigen-Induced Encephalomyelitis

Multiple sclerosis (MS) is a chronic, inflammatory, autoimmune disease of the central nervous system (CNS) which is associated with lower life expectancy and disability. The experimental antigen-induced encephalomyelitis (EAE) in mice is a useful animal model of MS, which allows exploring the etiopathogenetic mechanisms and testing novel potential therapeutic drugs. A new therapeutic paradigm for the treatment of MS was introduced in 2010 through the sphingosine 1-phosphate (S1P) analogue fingolimod (FTY720, Gilenya®), which acts as a functional S1P1 antagonist on T lymphocytes to deplete these cells from the blood. In this study, we synthesized two novel structures, ST-1893 and ST-1894, which are derived from fingolimod and chemically feature a morpholine ring in the polar head group. These compounds showed a selective S1P1 activation profile and a sustained S1P1 internalization in cultures of S1P1-overexpressing Chinese hamster ovary (CHO)-K1 cells, consistent with a functional antagonism. In vivo, both compounds induced a profound lymphopenia in mice. Finally, these substances showed efficacy in the EAE model, where they reduced clinical symptoms of the disease, and, on the molecular level, they reduced the T-cell infiltration and several inflammatory mediators in the brain and spinal cord. In summary, these data suggest that S1P1-selective compounds may have an advantage over fingolimod and siponimod, not only in MS but also in other autoimmune diseases.

Responsiveness of sphingosine phosphate lyase insufficiency syndrome to vitamin B6 cofactor supplementation

Sphingosine-1-phosphate (S1P) lyase is a vitamin B6-dependent enzyme that degrades sphingosine-1-phosphate in the final step of sphingolipid metabolism. In 2017, a new inherited disorder was described caused by mutations in SGPL1, which encodes sphingosine phosphate lyase (SPL). This condition is referred to as SPL insufficiency syndrome (SPLIS) or alternatively as nephrotic syndrome type 14 (NPHS14). Patients with SPLIS exhibit lymphopenia, nephrosis, adrenal insufficiency, and/or neurological defects. No targeted therapy for SPLIS has been reported. Vitamin B6 supplementation has therapeutic activity in some genetic diseases involving B6-dependent enzymes, a finding ascribed largely to the vitamin's chaperone function. We investigated whether B6 supplementation might have activity in SPLIS patients. We retrospectively monitored responses of disease biomarkers in patients supplemented with B6 and measured SPL activity and sphingolipids in B6-treated patient-derived fibroblasts. In two patients, disease biomarkers responded to B6 supplementation. S1P abundance and activity levels increased and sphingolipids decreased in response to B6. One responsive patient is homozygous for an SPL R222Q variant present in almost 30% of SPLIS patients. Molecular modeling suggests the variant distorts the dimer interface which could be overcome by cofactor supplementation. We demonstrate the first potential targeted therapy for SPLIS and suggest that 30% of SPLIS patients might respond to cofactor supplementation.

Devilishly radical NETwork in COVID-19: Oxidative stress, neutrophil extracellular traps (NETs), and T cell suppression

Pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and poses an unprecedented challenge to healthcare systems due to the lack of a vaccine and specific treatment options. Accordingly, there is an urgent need to understand precisely the pathogenic mechanisms underlying this multifaceted disease. There is increasing evidence that the immune system reacts insufficiently to SARS-CoV-2 and thus contributes to organ damage and to lethality. In this review, we suggest that the overwhelming production of reactive oxygen species (ROS) resulting in oxidative stress is a major cause of local or systemic tissue damage that leads to severe COVID-19. It increases the formation of neutrophil extracellular traps (NETs) and suppresses the adaptive arm of the immune system, i.e. T cells that are necessary to kill virus-infected cells. This creates a vicious cycle that prevents a specific immune response against SARS-CoV-2. The key role of oxidative stress in the pathogenesis of severe COVID-19 implies that therapeutic counterbalancing of ROS by antioxidants such as vitamin C or NAC and/or by antagonizing ROS production by cells of the mononuclear phagocyte system (MPS) and neutrophil granulocytes and/or by blocking of TNF-α can prevent COVID-19 from becoming severe. Controlled clinical trials and preclinical models of COVID-19 are needed to evaluate this hypothesis.

Suppression of Hyperactive Immune Responses Protects against Nitrogen Mustard Injury

DNA alkylating agents like nitrogen mustard (NM) are easily absorbed through the skin and exposure to such agents manifest not only in direct cellular death but also in triggering inflammation. We show that toxicity resulting from topical mustard exposure is mediated in part by initiating exaggerated host innate immune responses. Using an experimental model of skin exposure to NM we observe activation of inflammatory dermal macrophages that exacerbate local tissue damage in an inducible nitric oxide synthase (iNOS)-dependent manner. Subsequently these activated dermal macrophages reappear in the bone marrow to aid in disruption of hematopoiesis and contribute ultimately to mortality in an experimental mouse model of topical NM exposure. Intervention with a single dose of 25-hydroxyvitamin D3 (25(OH)D) is capable of suppressing macrophage-mediated iNOS production resulting in mitigation of local skin destruction, enhanced tissue repair, protection from marrow depletion, and rescue from severe precipitous wasting. These protective effects are recapitulated experimentally using pharmacological inhibitors of iNOS or by compounds that locally deplete skin macrophages. Taken together, these data highlight a critical unappreciated role of the host innate immune system in exacerbating injury following exposure to NM and support the translation of 25(OH)D in the therapeutic use against these chemical agents.

Reduction in radiation-induced lymphocytopenia by famotidine in patients undergoing radiotherapy for prostate cancer

BACKGROUND

Ionizing radiation causes a series of hematological alterations especially profound lymphocytopenia during and after the radiotherapy course. To investigate whether famotidine can reduce hematologic toxicity in patients treated with radiotherapy for prostate cancer.

METHODS

A total of 36 patients undergoing radiotherapy for prostate cancer were randomized to receive either placebo or famotidine tablets. Participants were pretreated with 40 mg of oral famotidine or placebo tablets twice daily, 4 and 3 hr before each radiotherapy fraction. The patients received external-beam radiotherapy up to 70 Gy. Complete blood counts with differential, platelet counts, and hemoglobin levels were obtained at baseline, biweekly during the treatment and once 4 weeks after the end of radiotherapy course. Magnitude of changes from baseline in the hematological parameters was determined and compared using Repeated Measures ANOVA.

RESULTS

Famotidine was well tolerated. A total of 112 blood samples were evaluated. A significant reduction in radiation-induced lymphocytopenia was noted in patients receiving famotidine than in patients receiving placebo (P = 0.006). No significant difference was observed between two groups for the decline in platelets, erythrocytes and leucocytes. For both groups, neutrophil, monocyte, eosinophil, and hemoglobin levels did not change significantly during the treatment.

CONCLUSIONS

Our results indicate that famotidine could result in a significant reduction in radiation-induced lymphocytopenia and may consequently increase radiotherapy efficacy as well as survival times. This radioprotective effect may be chiefly associated with its antioxidant and radical scavenging properties. Further studies are required to confirm these encouraging results.

Adalimumab reversed a severe lymphopenia in a patient with Crohn's disease

Patients with Crohn's disease are frequently found to have low peripheral lymphocyte counts. Lymphopenia has been linked to disease activity, the effects of therapy and the presence of an abnormal T regulatory (T(reg)) function. We present a patient with Crohn's disease and a severe total and CD4 lymphopenia that did not resolve after discontinuation of immunosuppressive treatment and resective surgery. Complete clinical remission and persistent normal levels of total and CD4 lymphocytes were observed after starting therapy with the anti-tumor necrosis factor monoclonal antibody adalimumab.

[Disseminated histoplasmosis, lymphopenia and Sjögren's syndrome]

Sjögren's syndrome is an autoimmune disease characterized by decreased exocrine gland secretions; patients may also present several hematological abnormalities, like lymphopenia. We describe the case of a 28 year old man who complained of headache a month of duration, with fever and vomiting in the last 48 hours. He also presented skin lesions on trunk and face, without neck stiffness. The diagnosis of duration infection was confirmed by culture from the skin biopsy and spinal fluid specimens; in addition, the presence of lymphopenia, positive anti Ro-SSA antibodies, poor concentration of the tracer in scintigraphy and lymphocytic infiltration in salivary glands confirmed the diagnosis of Sjögren's syndrome. the patient was successfully treated with liposomal amphotericin and itraconazole. We report this case to emphasize that opportunistic infections, such as disseminated histoplasmosis, may be an uncommon clinical presentation of Sjögren's syndrome.

[Good's syndrome with lymphopenia and neutropenia]

Good's syndrome (GS) is a rare immunodeficiency complicating thymoma and characterized by absence of B-cells, hypogammaglobulinaemia and a reduced CD4 T-cell level. Autoimmune neutropenia coexisting with GS is very unusual and carries a poor prognosis due to severe immunodeficiency. We report a case of a thymoma patient with GS and autoimmune neutropenia. Neutropenia disappeared on filgrastrim, prednisone and azathioprine treatment. However, the patient still suffers from GS and requires regular prophylactic immunoglobulin injections. On this treatment, the patient has survived for nine years.

Mechanisms involved in synergistic anticancer effects of anti-4-1BB and cyclophosphamide therapy

Chemotherapy can precondition for immunotherapy by creating an environment for homeostatic lymphoproliferation and eliminating some of the suppressive immune networks. We found that combination therapy with anti-4-1BB and cyclophosphamide (CTX) produced synergistic anticancer effects in the poorly immunogenic B16 melanoma model in mice. The antitumor effect of the combination therapy depended mainly on CD8(+) T cells, the 4-1BB-dependent expansion and differentiation of which into IFN-gamma-producing CD11c(+)CD8(+) T cells was enhanced by CTX. Anti-4-1BB induced a rapid repopulation of T and B cells from CTX-mediated lymphopenia. Anti-4-1BB protected naïve T cells from CTX and promoted proliferation of memory/effector and memory T cells. The combination treatment produced approximately 60- and 2.2-fold more CTLs per tumor-associated antigen compared with CTX or anti-4-1BB alone, respectively. This indicates that anti-4-1BB promoted a preferential expansion of tumor-specific CD8(+) T cells among the repopulated lymphocytes following CTX-mediated lymphopenia. CTX treatment enhanced 4-1BB expression on CD4 and CD8 T cells, and CTX alone or in combination with anti-4-1BB effectively suppressed peripheral regulatory T cells. Our results indicate that anti-4-1BB and CTX can be practical partners in cancer therapy because CTX creates an environment in which anti-4-1BB actively promotes the differentiation and expansion of tumor-specific CTLs.

IRX-2 and thymosin alpha1 (Zadaxin) increase T lymphocytes in T lymphocytopenic mice and humans

Mouse studies showed a synergy of thymosin alpha1 (Talpha1) and a natural cytokine mixture (IRX-2) in increasing T lymphocyte number and responses. Clinical studies with IRX-2 showed increases of T lymphocytes in lymphocytopenic cancer patients but relatively little effect on irradiated, lymphocytopenic patients. The present phase 1 and 2 study shows that Talpha1 enhances the effect of IRX-2 in these lymphocytopenic patients. Patients (seven) were treated with subcutaneously injected IRX-2 (200 units IL-2 equivalence), Talpha1 (1.6 mg/day) (four patients), or the combination of IRX-2 and Talpha1 (seven patients) daily for 10 days. Peripheral blood lymphocytes (T, B, NK) and subsets (CD4, CD8) were measured at the start of treatment and on day 11. IRX-2 and Talpha1 had little or no significant effect. The combination markedly increased various lymphocyte populations (>350 cells/microL). Four patients followed for 6 weeks displayed sustained increases involving both naïve and memory T cells. Responses to persistent infections were observed in three of the four patients and no significant toxicity was observed. Talpha1 and IRX-2 synergize to increase safely T cells in lymphocytopenic patients.

Melatonin as pharmacologic support in burn patients: a proposed solution to thermal injury-related lymphocytopenia and oxidative damage

OBJECTIVE

To review the data that support the clinical use of melatonin in the treatment of burn patients, with special emphasis on the stimulation of the oxidative defense system, the immune system, circadian rhythm of sleep/wakefulness, and the reduction in the toxicity of therapeutic agents used in the treatment of burn victims.

DATA SOURCE

A MEDLINE/PubMed search from 1975 to July 2006 was conducted.

STUDY SELECTION

The screening of the literature was examined using the key words: burn patients, lymphocytopenia, skin oxidative stress, antioxidant, melatonin, and free radicals.

DATA EXTRACTION AND SYNTHESIS

Thermal injury often causes damage to multiple organs remote from the original burn wound and may lead to multiple organ failure. Animal models and burn patients exhibit elevated free radical generation that may be causative in the local wound response and in the development of burn shock and distant organ injury. The suppression of nonspecific resistance and the disturbance in the adaptive immune system makes burn patients vulnerable to infections. Moreover, there is loss of sleep and the toxicity produced by drugs habitually used in the clinic for burn patients. Melatonin is a powerful antioxidant and is a potent protective agent against damage after experimental thermal injury. Some actions of melatonin as a potential supportive pharmacologic agent in burn patients include its: role as a scavenger of both oxygen and nitrogen-based reactants, stimulation of the activities of a variety of antioxidative enzymes, reduction in proinflammatory cytokines, inhibition of adhesion molecules, chronobiotic effects, and reduction in the toxicity of the drugs used in protocols to treat thermal injury patients.

CONCLUSIONS

These combined actions of melatonin, along with its low toxicity and its ability to penetrate all morphophysiologic membranes, could make it a ubiquitously acting and highly beneficial molecule in burn patients.

Lymphopenia-driven CD8+ T cells are resistant to antigen-induced tolerance in NOD.scid mice

T cells undergoing lymphopenia-driven proliferation acquire effector and memory properties that can be pathogenic. Indeed, generalized lymphopenia is associated with a variety of autoimmune diseases such as type 1 diabetes. The current study was carried out to determine how CD8(+) T cells undergoing acute lymphopenic expansion respond to antigen under tolerizing conditions in vivo. Adoptive transfer of diabetes by TCR-transgenic CD8(+) T cells was enhanced following treatment of NOD. scid recipients with a high dose of soluble peptide. Furthermore, whereas TCR-transgenic CD8(+) T cells underwent clonal deletion and failed to differentiate into CTL in peptide-treated lymphoreplete recipient mice, TCR-transgenic CD8(+) T cells in a lymphopenic environment were resistant to clonal deletion, and CTL differentiation was enhanced by a high dose of soluble peptide. Moreover, peptide treatment had distinct effects on expression of the anti-apoptotic protein Bcl-X(L) in TCR-transgenic CD8(+) T cells under lymphopenic versus lymphoreplete conditions. These results demonstrate that CD8(+) T cells undergoing lymphopenia-driven expansion in NOD. scid recipients are resistant to antigen-induced tolerance, and readily differentiate into CTL upon stimulation with a high dose of soluble peptide.

CD28 superagonists: mode of action and therapeutic potential

Some CD28-specific monoclonal antibodies (mAbs) have the surprising property to activate T-cells without the need for TCR ligation. This review summarizes the differences between these "superagonistic" and conventional CD28-specific mAbs with regard to binding specificity and signalling properties. Furthermore, the dramatic effects of in vivo application of CD28 superagonists with regard to the induction of regulatory T-cells and polyclonal T-cell expansion in lymphopenic settings are discussed under the aspect of potential therapeutic applications.

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.

Reduced thymic output, increased spontaneous apoptosis and oligoclonal B cells in polyethylene glycol-adenosine deaminase-treated patients

Impairment of purine metabolism due to adenosine deaminase (ADA) deficiency is associated with a severe combined immunodeficiency (SCID). Polyethylene glycol-modified ADA (PEG-ADA) has provided noncurative, life-saving treatment for these patients, but full immune recovery is not achieved with this therapy. Since ADA-SCID is perhaps the most difficult form of SCID to handle clinically, understanding the benefits and limitations of PEG-ADA therapy may be relevant for treatment selection. To this purpose, we analyzed the rate of thymic output, T and B cell repertoires, number of T cell divisions, IFN-gamma and IL-4 production, and the extent of cell death in five ADA-SCID patients following a prolonged period of treatment with PEG-ADA. We found that thymic output was low in these patients. However, their T cell repertoire was heterogeneous, and their T lymphocytes produced cytokines upon activation and responded to mitogen stimulation, although with different kinetics. Furthermore, a high number of peripheral T lymphocytes were committed to apoptosis. Anomalies were also observed in the B cell compartment, with oligoclonal expansions of B cell clonotypes in two patients. Our data indicate that decreased thymic function, B cell oligoclonality, and increased spontaneous apoptosis may be the mechanisms by which the immunodeficiency of ADA-SCID patients persists in spite of treatment with PEG-ADA.

Enhancement of the efficacy of chemotherapy with oxaliplatin plus 5-fluorouracil by pretreatment with IL-2 subcutaneous immunotherapy in metastatic colorectal cancer patients with lymphocytopenia prior to therapy

The present study was carried out to evaluate the influence of a short-period IL-2 administration on the efficacy of chemotherapy in metastatic colorectal cancer patients with pretreatment lymphocytopenia, which was defined as a lymphocyte count of less than 1500/mm3. The study included 144 consecutive metastatic colorectal cancer patients, who underwent chemotherapy with oxaliplatin plus 5-fluorouracil. Lymphocytopenia was seen in 41/144 (28%) patients, who were randomized to receive chemotherapy alone or chemotherapy after a prechemoimmunotherapy with IL-2 (3 MIU twice/day for 3 consecutive days), whereas patients with a normal pretreatment lymphocyte count received only chemotherapy. A normalization of the lymphocyte number was achieved in 12/19 lymphocytopenic patients pretreated with IL-2. The objective tumor regression rate achieved in patients with a normal lymphocyte count prior to chemotherapy was significantly higher compared to that obtained in lmphocytopenic patients treated with chemotherapy alone (54/103 vs. 3/22, p < 0.01), whereas no significant difference occurred between patients with normal lymphocyte count and lymphocytopenic patients pretreated with IL-2 (54/103 vs. 8/19). This study confirms that pretreatment lymphocytopenia is associated with reduced efficacy of chemotherapy in metastatic colorectal cancer patients. Moreover, it suggests that pretreatment with IL-2 before the onset of chemotherapy may enhance the efficacy of chemotherapy in lymphocytopenic patients. Therefore, the administration of IL-2 before the onset of chemotherapy to improve the immune status of cancer patients may be considered as a new chemoimmunotherapeutic combination, which may be recommended in the treatment of advanced cancer patients, particularly in those with cancer-related immune alterations.

What’s happening: An overview of potential adverse reactions associated with apheresis technology

The current status of potential adverse reactions associated with the use of apheresis technology is reviewed, focussing on three main areas: adverse events related to component collection, progenitor cells collection and therapeutic apheresis. Based on available information it is believed that apheresis technologies are safe and increasingly used in transfusion medicine, including in auto-transfusion and different types of therapy. Occasionally, however, for various donor/patient and operational reasons, mild or moderate adverse reactions do occur. The majority of these reactions are related to vascular access and anticoagulants used, which can be mostly eliminated with calcium/magnesium administration. The reactions associated with therapeutic apheresis are more frequent (6.75%) than the multi-components and stem cell collections. Most of these reactions are generally mild and only 0.89% has been classified as severe. A national registry of donor adverse reactions as well as a planned haemovigilance system may prove helpful in identifying the potential causes which might be associated with either to donor/donation and/or with a particular technology or procedure.

Efficacy and safety of methotrexate in recalcitrant cutaneous lupus erythematosus: results of a retrospective study in 43 patients

BACKGROUND

The therapy of cutaneous lupus erythematosus (CLE) is often challenging, especially in patients resistant to topical treatment and established first-line systemic drugs such as antimalarials. Systemic corticosteroids are effective, but their use is limited due to well-known side-effects, especially in long-term treatment. In recent years several other immunosuppressive agents have been successfully applied in CLE. However, there are no large studies or explicit guidelines on the use of these drugs in CLE.

OBJECTIVES

To perform a retrospective investigation of the efficacy of low-dose methotrexate (MTX) in the treatment of CLE.

METHODS

One hundred and thirty-nine patients with CLE were seen at our department between 2001 and 2003, of whom 43 patients required low-dose MTX. All had histologically confirmed CLE lesions. Clinical data including disease activity, additional treatment, laboratory parameters and side-effects were recorded carefully at the time of presentation. Statistical analyses were performed by paired nonparametric Wilcoxon test and Student's t-test using SPSS 11 software.

RESULTS

MTX led to a highly significant (P < 0.01) decline in disease activity. An improvement of the cutaneous lesions was recorded in nearly all patients treated with MTX (42 of 43; 98%). Severe side-effects necessitating discontinuation of MTX treatment were recorded in seven patients (16%), which quickly resolved when MTX was discontinued. Life-threatening complications were not observed. Intravenous application was tolerated better than oral administration. Interestingly, we observed a significant increase in circulating lymphocyte numbers in patients with lymphopenia (< 1.0 x 10(9) cells L(-1)) prior to MTX treatment.

CONCLUSIONS

Our study supports earlier findings reporting the efficacy of low-dose MTX in CLE lesions, particularly in recalcitrant clinical courses. MTX treatment appears to be safe if patients are carefully selected and monitored, with particular attention to side-effects and contraindications.

Lymphopenia and interleukin-2 therapy alter homeostasis of CD4+CD25+ regulatory T cells

CD4(+)CD25(+) regulatory T (T(reg)) cells have a crucial role in maintaining immune tolerance. Mice and humans born lacking T(reg) cells develop severe autoimmune disease, and depletion of T(reg) cells in lymphopenic mice induces autoimmunity. Interleukin (IL)-2 signaling is required for thymic development, peripheral expansion and suppressive activity of T(reg) cells. Animals lacking IL-2 die of autoimmunity, which is prevented by administration of IL-2-responsive T(reg) cells. In light of the emerging evidence that one of the primary physiologic roles of IL-2 is to generate and maintain T(reg) cells, the question arises as to the effects of IL-2 therapy on them. We monitored T(reg) cells during immune reconstitution in individuals with cancer who did or did not receive IL-2 therapy. CD4(+)CD25(hi) cells underwent homeostatic peripheral expansion during immune reconstitution, and in lymphopenic individuals receiving IL-2, the T(reg) cell compartment was markedly increased. Mouse studies showed that IL-2 therapy induced expansion of existent T(reg) cells in normal hosts, and IL-2-induced T(reg) cell expansion was further augmented by lymphopenia. On a per-cell basis, T(reg) cells generated by IL-2 therapy expressed similar levels of FOXP3 and had similar potency for suppression compared to T(reg) cells present in normal hosts. These studies suggest that IL-2 and lymphopenia are primary modulators of CD4(+)CD25(+) T(reg) cell homeostasis.

Herpetic whitlow as a harbinger of pediatric HIV-1 infection

Herpetic whitlow applies to a primary or recurrent herpes simplex infection of the fingers. It is a rare condition in immunocompetent patients, and usually has a rapid evolution and prompt response to treatment. We report a 10-year-old girl referred to our department of infectious diseases with recurrent and unresponsive ulcerated and necrotic lesions of the fingers of both hands as a first sign of human immunodeficiency virus infection. Numerous instances of extensive or recurrent herpes lesions of the mouth, lips, and perianal areas have been found in the literature, but we have not found any report of periungual infection as a first manifestation of human immunodeficiency virus infection. Pediatricians and dermatologists need to be aware of this association in order to make an early diagnosis and start treatment of these patients' disease.

Interleukin-7 improves reconstitution of antiviral CD4 T cells

We evaluated whether long-term (2 months) administration of interleukin-7 (IL7) hastens immune recovery in baboons rendered severely lymphopenic by total body irradiation and antithymocyte globulin (ATG). Four baboons were treated with recombinant baboon IL7 and three baboons with placebo. Median CD4 T cell count at the end of IL7/placebo treatment was higher in the IL7-treated animals (2262 vs. 618/microl, P = 0.03). This appeared to be a result of peripheral expansion rather than de novo generation. Median cytomegalovirus (CMV)-specific IFNgamma-producing CD4 T cell count at the end of IL7/placebo treatment was higher in the IL7-treated animals (122 vs. 1/microl, P = 0.03). All animals were pretransplant cytomegalovirus-seropositive. One animal died at the end of IL7 treatment; necropsy showed extensive T cell infiltration of kidneys and lungs. In conclusion, IL7 stimulates the expansion of CD4 T cells, including functional antiviral cells. Clinical risk-benefit ratio needs to be evaluated.

IL-7 and Flt-3L plasma levels are increased during highly active antiretroviral therapy-associated IL-2 therapy

IL-2 is used in conjunction with highly active antiretroviral therapy to increase the CD4 cell count in HIV-positive patients. The mechanisms involved remain ill-defined. Here we show that during the first cycle of IL-2 therapy, IL-7 and Flt-3L plasma levels are increased, whereas levels of stem cell factor are unchanged. This supports the hypothesis that aside from stimulating CD4 T cells IL-2 may also indirectly affect lymphocyte production through the stimulation of lymphopoietic cytokines.

Recombinant interleukin-7 induces proliferation of naive macaque CD4+ and CD8+ T cells in vivo

Interleukin-7 (IL-7) regulates T-cell homeostasis, and its availability is augmented in lymphopenic hosts. Naive CD8+ T cells transferred to lymphopenic mice acquire a memory-like phenotype, raising the possibility that IL-7 is the biological mediator of this effect. Here, we provide direct evidence that IL-7 induces the acquisition of memory-cell markers not only in CD8+ T cells but also in CD4+ T-cell subsets in immune-competent Indian rhesus macaques. The increase of these memory-like populations was dependent on the dose of the cytokine, and these cells were found in the blood as well as secondary lymphoid organs. Memory-like CD4+ and CD8+ T cells acquired the ability to secrete tumor necrosis factor alpha and, to a lesser extent, gamma interferon following stimulation with a cognate antigen. The phenotypic change observed in naive T cells was promptly reversed after discontinuation of IL-7. Importantly, IL-7 induced cycling of both CD4+ and CD8+ central memory and effector memory T cells, demonstrating its contribution to the maintenance of the entire T-cell pool. Thus, IL-7 may be of benefit in the treatment of iatrogenic or virus-induced T-cell depletion.

Sphingosine 1-phosphate receptor agonists attenuate relapsing–remitting experimental autoimmune encephalitis in SJL mice

FTY720 is a prodrug for FTY-phosphate, an agonist at four of the five known receptors for sphingosine-1-phosphate (S1P). We show that administration of either FTY720 or FTY-P to SJL mice with established relapsing-remitting experimental autoimmune encephalitis (EAE) results in a rapid and sustained improvement in their clinical status, and a reversal of changes in expression of mRNAs encoding some myelin proteins and inflammatory mediators. EAE produced by adoptively transferring lymph node cells from immunized mice to naïve hosts is similarly ameliorated by FTY-P. Treatment with FTY-P is accompanied by a dose-responsive peripheral lymphopoenia.

Normalization of peripheral blood cell composition by lactoferrin in cyclophosphamide-treated mice

BACKGROUND

Cyclophosphamide (CP) is used in the treatment of autoimmune disorders and leukemia. The compound induces severe leuko- and neutropenia. Lactoferrin (LF) is a protein which plays a role in the innate immunity. In this study we evaluated the usefulness of LF in reversing CP-induced lympho- and neutropenia in mice.

MATERIAL/METHODS

CBA mice were treated with CP (350 mg/kg body weight, intraperitoneally) and given LF as a 0.5% addition to drinking water. Alternatively, LF was administered orally (seven doses, 1 mg each) on alternate days following CP injection. Control groups received CP or LF only. Blood samples were taken before treatment and on days 4, 8, 15 and 22 following CP injection to determine leukocytosis and cell types in blood smears.

RESULTS

Mice treated with CP showed severe leukopenia, strong eosinophilia (day 4), and an altered lymphocyte/neutrophil ratio (days 8-22). Treatment of mice with LF for 21 days partially normalized the cell composition in CP-treated mice (increased percentage of lymphocytes and decreased eosinophil content). The content of leukocytes increased upon LF treatment on days 4, 8, 15 and 22 (by 36.8, 39.5, 72 and 70.7%, respectively). More importantly, LF partly normalized the neutrophil and lymphocyte composition on day 22 (neutrophils: 29.2% in control mice, 50.6% in CP-treated, and 39.16% in CP/LF-treated; lymphocytes: 66.18% in control mice, 35% in CP-treated and 48.8% in CP/LF-treated). Administration of LF alone did not change the cell numbers or composition.

CONCLUSIONS

LF given orally to CP-immunocompromised mice accelerates reconstitution of lymphopoiesis and myleopoiesis.

A patient with paroxysmal nocturnal haemoglobinuria in whom granulocyte colony-stimulating factor administration resulted in improvement of recurrent enterocolitis and its associated haemolytic attacks

We report an elderly patient with paroxysmal nocturnal haemoglobinuria (PNH), having recurrent enterocolitis and haemolytic attacks associated with cellular immunodeficiency. On admission, the patient had normal neutrophil count and function but a decreased T-cell count, decreased mitogenic reactions, and a negative tuberculin test. Granulocyte colony-stimulating factor (G-CSF) was administered, resulting in an increased T-cell count, normalization of T-cell function, increased blood levels of helper T cell (Th)1 and Th2 cytokines and improvement in the enterocolitis and haemolytic attacks. This suggests that G-CSF may be useful in the treatment of elderly PNH patients with cellular immunodeficiency.

Potential for immune reconstitution through G-CSF treatment of HIV patients

New treatment strategies for HIV/AIDS are very successful in reducing viral load. However, reconstitution of the immune system takes about one year and may be insufficient or remain incomplete. During this time the patient remains prone to opportunistic infections as a result of the complex immune dysfunction caused by the virus. Recombinant granulocyte colony-stimulating factor (G-CSF) has diverse immunomodulatory properties which may be beneficial in aiding immune reconstitution.

[Immunomodulatory treatment of lymphopenia after infectious mononucleosis]

Persistent lymphopenia of various intensity has been noted in 45% of persons who had a history of infectIous mononucleosis. The group consisted od 500 patients, (236 males and 264 females). In all of them the diagnosis of mononucleosis had been based on the characteristic clinical signs and symptoms and changes in the blood picture and confirmed by the non-specific and/or specific serologic tests. In 33 persons (10 males and 18 females) the total number of lymphocytes varied from 884 to 992 per 1 cmm, the distribution being as follows: B lymphocytes--146 to 198, CD4--482 to 645 and CD8--245 to 364 per 1 cmm. 18 persons (18 males and 10 females) were given thymosine (TFX) subcutaneously for 30 days in the dose of 0.02 g daily, the remaining 15 (7 males and 8 females) received 3.0 g of isoprinosine per day for the same period. The total lymphocytes count and that of B, CD4 and CD8 was performed before and after the treatment and then followed once a month until 180 days since the treatment had been started. The TFX therapy was repeated after 8-12 months since the end of the first course in 3 patients and that with isoprinosine in 4. The strategy and the examination pattern were the same as before, control examinations being performed every 6 months and final analysis was done after 5 years of follow-up. Among the 33 patients who received immunomodulating treatment, normalisation of the lymphocytes count appeared in 24 (64%). Among the 12 persons with less pronounced lymphopenia, who did not received any treatment, spontaneous normalisation appeared in 5 (40%). It may be therefore assumed, that in persons with the history of infectious mononucleosis with persistent marked lymphopenia, thymosine and isoprinosine may be used in the therapy as additional immunomodulators.

Effect of cytokines on HIV-induced depletion of thymocytes in vivo

BACKGROUND

Cytokines play an important role in the differentiation of thymocytes into mature T cells; consequently, certain cytokines could be useful for immune reconstitution after HIV infection without increasing viral load.

OBJECTIVE

To investigate whether cytokines affect immune depletion caused by HIV infection with a CXCR4-tropic strain in SCID-hu mice implanted with human fetal thymus and liver (thy/liv) tissue.

METHODS

The thy/liv implants were either mock infected or infected with HIV-1 NL4-3, a CXCR4-tropic molecular clone. Interleukin (IL)-2, IL-4, IL-7, interferon-gamma (IFN-gamma) or diluent was administered to the mice during the second and third week postinfection. Viral load and immunophenotype were determined in thymocytes.

RESULTS

Thymocyte subset distributions at 3 weeks postinfection were significantly influenced by treatment with certain cytokines. In particular, IL-2 caused the infected mice to retain a thymocyte profile that was more similar to that in mock-infected mice than that in diluent-treated infected mice, in that the percentages of immature CD4+CD8+ and CD5+CD1+ cells were slightly higher and much less variable than in diluent-treated infected mice. The effect of IFN-gamma treatment was similar to IL-2 but did not reach statistical significance. However, after IFN-gamma treatment, normal percentages of mature CD3+CD69+ cells were maintained whereas this population was relatively increased in diluent-treated infected mice. Although treatment with IL-4 and IL-7 delayed depletion of immature thymocytes, these cytokines increased viral load.

CONCLUSIONS

Cytokines such as IL-2 and IFN-gamma maintain immature thymocytes without increasing viral load and may be useful as adjuncts to improve immune reconstitution after HIV infection.

Two cases of idiopathic CD4+ T-lymphocytopenia in elderly patients

We present 2 cases of idiopathic CD4+ T-lymphocytopenia (ICL) in elderly patients. Case 1, a 73-year-old man, with pneumonia had received several antibiotics with unsuccessful results at another hospital. On admission, his CD4+ T-lymphocyte count was 109/microl and Pneumocystis carinii was detected by bronchoalveolar lavage fluid staining. No evidence of human immunodeficiency virus (HIV) infection was found. Despite therapy, the patient died of respiratory failure. Case 2, a 72-year-old man, contracted severe pneumonia, and Hemophillus influenzae was believed to be the pathogen. On admission, his CD4+ T-lymphocyte count was 238/microl. No evidence of HIV infection was found. He received antibiotics and improved successfully. We suggest that ICL may currently be incubating in a number of elderly pneumonia patients.

Rapid reemergence of T cells into peripheral circulation following treatment of severe and uncomplicated Plasmodium falciparum malaria

Frequencies and absolute numbers of peripheral T-cell subsets were monitored closely following acute Plasmodium falciparum malaria in 22 Ghanaian children from an area of hyperendemicity for seasonal malaria transmission. The children presented with cerebral or uncomplicated malaria (CM or UM, respectively) or with severe malarial anemia. For all patients the frequencies and absolute numbers of peripheral T cells were lower than normal during the acute stage of disease. This lowering was most pronounced in the CM group and least pronounced in the UM group. Of particular interest, the CM patients showed markedly reduced frequencies of CD4+ cells, the number of which also normalized slower than in the other clinical groups. In all patients, the T-cell frequencies gradually approached normal values after the initiation of therapy, whereas the absolute numbers rapidly reverted from lower than normal to higher than normal before returning to steady-state levels. Furthermore, the initially reduced T-cell surface density of the T-cell receptor/CD3 complex, which rapidly normalized, was a general finding for all three clinical groups, suggesting a state of peripheral T-cell hyporesponsiveness during acute malaria. The data presented suggest a rapid therapy-induced reemergence of T cells that had been temporarily removed from the peripheral circulation as a consequence of the malaria attack and that the degree of the disease-induced T-cell reallocation correlates with disease severity.

Hematologic disorders and growth factor support in HIV infection

During the course of HIV disease a broad spectrum of hematologic disorders develop including abnormalities in blood cell generation, survival, and function Alterations in coagulation parameters may evolve associated with disruption of immunoglobulin or factor production. This article reviews the manifestations and pathophysiology of these abnormalities and discusses the role for growth factor support.

M. Kansasii pulmonary disease in idiopathic CD4+ T-lymphocytopenia

Cases of patients with markedly depressed CD4+ T-lymphocyte counts, with or without opportunistic infections, in the absence of any evidence of human immunodeficiency virus (HIV) have been described in recent years. In 1992, the definition of "idiopathic CD4+ T-lymphocytopenia" was formulated by the Centers for Disease Control and Prevention (CDC) of Atlanta (USA). The present case illustrates the occurrence of an unexplained Mycobacterium kansasii pneumonia in a white HIV-negative subject with a persistent depletion of CD4+ T-lymphocytes and suppression of cell-mediated immunity. To our knowledge, this is the first observation of idiopathic CD4+ T-lymphocytopenia with pulmonary mycobacteriosis due to Mycobacterium kansasii, and the sixth case of this kind of immunodeficiency described in Italy.