Case report: The devil was hidden in the mastocytes - an unusually fulminant case of indolent systemic mastocytosis in a 45-year-old patient, missed for almost 20 years

Indolent systemic mastocytosis (ISM) represents the most common form of SM, typically following a slow clinical course. While anaphylactic reactions may come up in the life course of an ISM patient, these are often moderate and do not pose a threat to patient's health. Here, we present an undiagnosed case of ISM with recurrent severe anaphylactic episodes following consumption of food and emotional stress. One of these episodes led to anaphylactic shock, necessitating temporary mechanical ventilation and intensive care unit (ICU) support. Besides hypotension, a diffuse, itchy, red rash was the only notable clinical finding. Upon recovery, we found abnormally high baseline serum tryptase level as well as 10% bone marrow (BM) infiltration by multifocal, dense clusters of CD117+/mast cell tryptase+/CD25+ mast cells (MCs), consolidating the diagnosis of ISM. Prophylactic treatment with a histamine receptor antagonist was initiated, resulting in milder episodes thereafter. Diagnosis of ISM requires a high level of suspicion; its prompt recognition and treatment are important in preventing potentially life-threatening anaphylactic episodes.

Treatment with 3-day methylprednisolone pulses in severe cases of COVID-19 compared with the standard regimen protocol of dexamethasone

Since the outbreak of COVID-19, research has been focused on establishing effective treatments, especially for patients with severe pneumonia and hyperinflammation. The role and dose of corticosteroids remain obscure. We evaluated 58 patients with severe COVID-19 during two periods. 24 patients who received methylprednisolone pulses (250 mg/day intravenously for 3 days) were compared with 34 patients treated according to the standard dexamethasone protocol of 6 mg/day. Among non-intubated patients, the duration of hospitalization was shorter for those who received methylprednisolone pulses (9.5 vs 13.5, p<0.001). In a subgroup analysis of patients who required intubation, those treated with the dexamethasone protocol demonstrated a relative risk=1.89 (p=0.09) for dying, in contrast to the other group which showed a tendency towards extubation and discharge from the hospital. A 'delayed' need for intubation was also observed (6 vs 2 days, p=0.06). Treatment with methylprednisolone pulses significantly reduced hospitalization time. Although there was no statistically significant influence on the necessity for intubation, methylprednisolone pulses revealed a tendency to delay intubation and hospital discharges. This treatment could benefit patients in the hyperinflammatory phase of the disease.

Syphilis infection in an HIV patient presenting with leukemoid reaction: Case report and review of the literature

Leukemoid reaction (LR) is an uncommon though dreadful sign for the treating physician, as it is related to increased mortality. In the few series that have addressed its incidence and clinical significance, infectious causes count for about half of the cases of LR, the rest accounting for cancer, drugs or rarer causes. In the HIV setting, it represents an even rarer event, owing probably to the impaired granulocytic response of AIDS patients to bacterial agents. However no report exists as to the incidence of LR to the immune-restored HIV patients adequately treated with antiretroviral therapy (ART). Syphilis is a well known cause of mild lymphocytosis, though only one report of LR exists in the congenital setting. We hereby report a case of an HIV patient adequately treated with ART, who presented with LR with a lymphomonocytic preponderance after infection with treponema pallidum.

Successful Treatment of immune Reconstitution Inflammatory syndrome-related Hemophagocytic Syndrome in an HIV Patient with Primary Effusion Lymphoma

Although the connection of [secondary hemophagocytic syndrome (sHS)] with HIV has been well documented, optimal treatment regimen is not well established. This is due not only to the rarity of the syndrome, but also to the heterogeneity of the involved population. Most cases are related to opportunistic infections or malignancies in advanced stage, but many cases are also related to seroconversion, in the primary infection setting. Moreover, in the [antiretroviral treatment (ART)] era, rare cases of ART-related sHS have been reported. In these, often fatal cases, an [immune reconstitution inflammatory syndrome (IRIS)] process is involved, posing a serious challenge to the treating physician. We hereby report a case of successful treatment of an HIV patient with primary effusion lymphoma who experienced sHS shortly after ART onset. Our patient, treated with high dose dexamethasone and gamma globulin, achieved complete remission. This case might hint possible therapeutic insights in the treatment of IRIS-related sHS.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

In vitro anti-inflammatory and anti-coagulant effects of antibiotics towards Platelet Activating Factor and thrombin

BACKGROUND

Sepsis is characterized as a systemic inflammatory response that results from the inability of the immune system to limit bacterial spread during an ongoing infection. In this condition the significant mediator of inflammation Platelet Activating Factor (PAF) and the coagulant factor thrombin are implicated. In animal models, treatment with PAF-antagonists or co-administration of antibiotics with recombinant-PAF-Acetylhydrolase (rPAF-AH) have exhibited promising results. In order to examine the putative anti-inflammatory and/or antithrombotic interactions between antibiotic treatment used in sepsis with PAF and/or thrombin, we studied the in vitro effects of these compounds towards PAF or/and thrombin related activities and towards PAF basic metabolic enzymes.

METHODS

We assessed the inhibitory effect of these drugs against PAF or thrombin induced aggregation on washed rabbit platelets (WRPs) or rabbit Platelet Reach Plasma (rPRP) by evaluating their IC50 values. We also studied their effect on Cholinephosphotransferase of PAF (PAF-CPT)/Lyso-PAF-Acetyltransferase (Lyso-PAF-AT) of rabbit leukocytes (RLs), as well as on rabbit plasma-PAF-AH, the key enzymes of both de novo/remodelling PAF biosynthesis and PAF degradation, respectively.

RESULTS

Several antibiotics inhibited PAF-induced platelet aggregation of both WRPs and rPRP in a concentration-depended manner, with clarithromycin, azithromycin and amikacin exhibiting the higher inhibitory effect, while when combined they synergistically inhibited PAF. Higher concentrations of all antibiotics tested were needed in order to inhibit PAF induced aggregation of rPRP, but also to inhibit thrombin induced aggregation of WRPs. Concentrations of these drugs similar to their IC50 values against PAF activity in WRPs, inhibited also in vitro PAF-CPT and Lyso-PAF-AT activities of rabbit leukocytes, while only clarithromycin and azithromycin increased rabbit plasma-PAF-AH activity.

CONCLUSIONS

These newly found properties of antibiotics used in sepsis suggest that apart from their general actions, these drugs may present additional beneficial anti-inflammatory and anti-coagulant effects against the onset and establishment of sepsis by inhibiting the PAF/PAF-receptor and/or the thrombin/protease-activated-receptor-1 systems, and/or by reducing PAF-levels through both PAF-biosynthesis inhibition and PAF-catabolism induction. These promising in vitro results need to be further studied and confirmed by in vivo tests, in order to optimize the efficacy of antibiotic treatment in sepsis.

Anti-platelet-activating factor effects of highly active antiretroviral therapy (HAART): a new insight in the drug therapy of HIV infection?

Platelet-activating factor (PAF) is a potent inflammatory mediator, which seems to play a role in the pathogenesis of several AIDS manifestations such as AIDS dementia complex, Kaposi's sarcoma, and HIV-related nephropathy. PAF antagonists have been studied in these conditions with promising results. In order to examine the possible interactions between PAF and antiretroviral therapy, we studied the effect of nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors against PAF biological activities and its basic biosynthetic enzymes dithiothreitol-insensitive PAF-cholinephosphotransferase (PAF-CPT) and lyso-PAF-acetyltransferase (Lyso-PAF-AT), as well as its main degradative enzyme PAF-acetylhydrolase, of human mesangial cell line (HMC). We also studied the effect of several backbones and highly active antiretroviral therapy (HAART) regimens against PAF activity. Among the drugs tested, several inhibited PAF-induced platelet aggregation in a concentration-depended manner, with tenofovir, efavirenz, and ritonavir exhibiting the higher inhibitory effect. In addition, when these drugs were combined in backbones and HAART regimens based on American antiretroviral therapy proposals, they also synergistically exhibited an inhibitory effect against PAF-induced platelet aggregation. Several of these drugs have also inhibited in vitro microsomal PAF-CPT activity, and concentrations of lopinavir-r or tenofovir-DF (similar to their IC(50) against PAF-induced platelet aggregation) exhibited the same effect against PAF-CPT and Lyso-PAF-AT when added in the cell medium of cultured HMC. In addition, in naïve patients treated with one of the most potent anti-PAF HAART regimens (efavirenz/emtricitabine/tenofovir-DF) for a period of 1 month, a significant reduction of the specific activity of PAF-CPT of washed human leukocytes of these patients was also observed, compared with its levels before the HAART treatment. These promising results need to be further studied and confirmed by additional in vivo tests in order to optimize HAART efficacy.

Dynamics of aggregation and emergence of cooperation

Aggregation is one of the most basic social phenomena, and many activities of social insects are linked to it. For instance, the selection of a valuable site and the spatial organization of the population are very often by-products of amplifications based on the local density of nestmates. The patterns of aggregation are very diverse, ranging from the gathering of all animals in a unique site to their splitting between several ones. One might question how these multiple patterns emerge. Do ants actively initiate the formation of such patterns by modulating the emission of an attracting signal such as the trail pheromone? Alternatively, do patterns result from quantitative changes in the duration of interaction between animals once they have reached the gathering site, without any active modulation of the communications? To discuss these questions, we present two empirical studies: the gregarious behavior of cockroaches (Blatella) and self-assembly in the weaver ant (Oecophylla). Through experimental and theoretical studies, we show how a single behavior-the resting time-leads to a collective choice in both species. This behavior is a response to the density of conspecifics and can also be modulated by heterogeneities in the environment. In weaver ants, it allows the colony to focus the formation of chains in a given area among several potential sites. In cockroaches, it allows the gathering of individuals in particular shelters, depending on the proximity between strains. These results are discussed with emphasis on the role of aggregation processes in the emergence of cooperativity and task allocation.

Model of droplet dynamics in the Argentine ant Linepithema Humile (Mayr)

The formation of droplets of ants Linepithema humile (Mayr) is observed under certain experimental conditions: a fluctuating aggregate forms at the end of a rod and a droplet containing up to 40 ants eventually falls down. When the flux of incoming ants is sufficient, this process can continue for several hours, leading to the formation and fall of tens of droplets. Previous work indicates that the time series of drop-to-drop intervals may result from a nonlinear low-dimensional dynamics, and the interdrop increments exhibit long-range anticorrelations. A model of aggregation and droplet formation, based on experimental observations, is introduced and shown to reproduce these properties.

Efficacy of ondansetron treatment with different timing schedules: a randomized double-blind study

The purpose of this study was to determine whether preloading administration of ondansetron given 12.5 h before cisplatin therapy, every 6 h, is better in controlling acute cisplatin-induced emesis than a standard dose every 8 h. All patients had previously received three cycles of CDDP-based chemotherapy in a dose of 100 mg/m2. Ondansetron was given according to two schedules: in group A (40 patients) at a dose of 8 mg in 100 ml normal saline over 10 min by intravenous infusion before the infusion of CDDP continued with 1 tablet of 8 mg after 8 and 16 h; in group B (40 patients) it was administered in six intravenous doses (every 6 h) starting 12.5 h before cisplatin administration. During the following 3 days, patients from both groups continued with tablets of 8 mg orally, every 8 h in group A and every 6 h in group B. The only difference in terms of the antiemetic response noticed between the two groups was in the number of patients that presented with nausea, which was increased in group A (32) in comparison to group B (25; p < 0.022). No difference was found in the number of vomiting episodes, retches or control of emesis, during the 3-day evaluation period after cisplatin infusion, and in secondary side effects. In conclusion the total dose of 24 mg ondansetron during the acute phase of emesis is as effective as preloading and increasing the total dose to 32 mg.

Comparison of ondansentron versus ondansentron plus methylprednisolone as antiemetic prophylaxis during cisplatin-containing chemotherapy

We compared the antiemetic efficacy of ondansentron versus ondansentron and corticosteroids in cisplatin-induced emesis. None of our patients had received prior chemotherapy. All patients received chemotherapy including cisplatin 100 mg/m2. Forty patients received ondansentron alone (Group A) and 40 the combination of ondansentron and methylprednisolone (Group B). Ondansentron was given at a dose of 8 mg in 100 mL N/S over 10 min by intravenous infusion. The initial dose was administered before the cisplatin and was followed by 8 mg orally in the afternoon and before sleeping the first day of chemotherapy. During the next 2 days, the patients received 8 mg orally 3 times daily. Methylprednisolone was given as an intravenous bolus of 40 mg before chemotherapy and then together with each dose of ondansentron at a dose of 16 mg orally. Group A had significantly longer duration of nausea after chemotherapy than group B (117 +/- 111 min, 62 +/- 71 min, P < 0.013). The response on emesis was also improved in group B, especially the day of chemotherapy [treatment failure: group A: 13 patients (30%) versus group B: 5 patients (11.6%), P < 0.03] and the next day [complete response: group A: 17 patients (39.5%) versus group B: 30 patients (69.7%), P < 0.005]. Patients in group B presented more sedative effects (P < 0.001) and better appetite (P < 0.02) than patients in group A. There were no other significant differences in side effects (activity, headache, constipation, etc). We conclude that corticosteroids improve the antiemetic efficacy of ondansentron in cisplatin-induced chemotherapy, and should be included in antiemetic regimens.