Severity of asthma: the role of CD25+, CD30+, NF-kappaB, and apoptotic markers

OBJECTIVES

We studied the role of the regulatory T cells CD4+CD25+ (Treg) and activated CD4+CD30+ cells in the pathogenesis of asthma and their association with apoptosis and NF-kappaB in patients with mild intermittent asthma (MA), severe persistent asthma (SA), and healthy volunteers (HV).

METHODS

Peripheral blood lymphocytes (PBL) were extracted from asthmatic patients during exacerbations, and CD4+ cells were separated using Dynal beads. Immunostaining of whole PBL for NF-kappaB, Bax, and Bcl-2, and immunostaining of CD4+ cells for CD25+ and CD30+ cells were performed using immunocytochemistry.

RESULTS

Treg cells were expressed at higher levels in MA than in HV and SA (P < .05), while CD30+ T cells were expressed at higher levels in both SA and MA than in HV (P < .05), although there was no remarkable difference between SA and MA (P>.05). Levels of NF-kappaB, Bcl-2, and Bcl-2/Bax increased, whereas those of Bax decreased, progressively, from MA to SA (P < .05). NF-kappaB levels correlated directly with the Bcl-2/Bax ratio and with CD4+CD30+ cells in SA and MA, whereas CD4+CD30+ cells correlated inversely with the Bcl-2/Bax ratio.

CONCLUSIONS

Unregulated Treg cells probably return inflammatory responses to normal values during exacerbations in MA; however, expression of Treg cells was extensively diminished in SA, leading to probable loss of suppressive control over underlying immune reactions. CD4+CD30+ cells were associated with the pathogenesis of asthma but not with severity. NF-kappaB seems to be the central inflammatory factor in SA, with a remarkable loss of PBL apoptosis, diminished Treg levels, and high CD30+ cell levels that probably induce NF-kappaB, which in turn blocks the proapoptotic potential of CD30 induction itself.

Changing survival, memory cell compartment, and T-helper balance of lymphocytes between severe and mild asthma

Background

Asthma is a complicated network of inflammatory reactions. It is classified into mild, moderate, and severe persistent asthma. The success of asthma therapy relies much on understanding the underlying mechanisms of inflammation at each stage of asthma severity. The aim of this study was to explore the differences in apoptotic potential, CD4/CD8 ratio, memory compartment, and T- helper (Th) 1 and 2 profile of peripheral blood lymphocytes (PBL) in patients with mild intermittent asthma and severe persistent asthma during exacerbation periods.

Results

Four research lines were investigated and compared among mild asthmatics, severe asthmatics, and healthy groups by applying immunocytochemical staining of PBL. Antiapoptotic and proapoptotic proteins with Bcl-2/Bax ratio, CD4, CD8 markers with CD4⁺/CD8⁺ ratio, CD45RO⁺, CD45RA⁺ markers with memory/naïve ratio (CD45RO⁺/CD45RA⁺). Th2/Th1 cytokines balance represented by IL-4/IFN-γ ratio was measured by enzyme-linked immunosorbent assay (ELISA) for in vitro PBL cytokine synthesis. It was found that Bcl-2/Bax ratio was higher in severe than in mild asthmatics which in turn was higher than in healthy group. And memory/naïve ratio of PBL was higher in severe than in mild asthmatics. Moreover, memory cells, CD45RO⁺ and CD45RO⁺/CD45RA⁺ ratio were correlated directly with Bcl-2/Bax, in severe and mild asthma patients. In contrast, CD4⁺/CD8⁺ ratio was not changed significantly among healthy group, mild and severe asthmatics. However, CD8⁺ cells were correlated directly with memory cells, CD45RO⁺, in severe asthmatics only. Interestingly, the dominant profile of cytokines appeared to change from T helper 2 (Th2) in mild asthmatics to T helper 1 (Th1) in severe asthmatics where the lowest in vitro IL-4/IFN-γ ratio and highest IFN-γ were found.

Conclusion

It was concluded that the underlying mechanisms of inflammation might vary greatly with asthma stage of severity. Mild intermittent asthma is mainly Th2 allergen-oriented reaction during exacerbations with good level of apoptosis making the inflammation as self-limiting, while in severe persistent asthma, the inflammatory reaction mediated mainly by Th1 cytokines with progressive loss of apoptosis leading to longer exacerbations, largely expanded memory cells, CD45RO⁺, leading to persistent baseline inflammation.

The distinctive profile of risk factors of nasopharyngeal carcinoma in comparison with other head and neck cancer types

BACKGROUND

Nasopharyngeal carcinoma (NPC) and other head and neck cancer (HNCA) types show a great epidemiological variation in different regions of the world. NPC has multifactorial etiology and many interacting risk factors are involved in NPC development mainly Epstein Barr virus (EBV). There is a need to scrutinize the complicated network of risk factors affecting NPC and how far they are different from that of other HNCA types.

METHODS

122 HNCA patients and 100 control subjects were studied in the region of the Middle East. Three types of HNCA were involved in our study, NPC, carcinoma of larynx (CL), and hypopharyngeal carcinoma (HPC). The risk factors studied were the level of EBV serum IgG and IgA antibodies measured by ELISA, age, sex, smoking, alcohol intake, histology, and family history of the disease.

RESULTS

EBV serum level of IgG and IgA antibodies was higher in NPC than CL, HPC, and control groups (p < 0.01). NPC was associated with lymphoepithelioma (LE) tumors, males, regular alcohol intake, and regular smoking while CL and HPC were not (p < 0.05). CL and HPC were associated with SCC tumors (p < 0.05). Furthermore, NPC, unlike CL and HPC groups, was not affected by the positive family history of HNCA (p > 0.05). The serum levels of EBV IgG and IgA antibodies were higher in LE tumors, regular smokers, younger patients, and negative family history groups of NPC patients than SCC tumors, non-regular smokers, older patients and positive family history groups respectively (p < 0.05) while this was not found in the regular alcoholics (p > 0.05).

CONCLUSION

It was concluded that risk factors of NPC deviate much from that of other HNCA. EBV, smoking, alcohol intake, LE tumors, male patient, and age > 54 years were hot risk factors of NPC while SCC and positive family history of the disease were not. Earlier incidence, smoking, LE tumors, and negative family history of the disease in NPC patients were associated much clearly with EBV. It is proposed that determining the correct risk factors of NPC is vital in assigning the correct risk groups of NPC which helps the early detection and screening of NPC.

Therapeutic re-appraisal of multiple drug resistant Salmonella typhi (MDRST) in Pakistani children

BACKGROUND

The emergence of multi drug-resistant Salmonella typhi (MDRST) in many developing countries including Pakistan, has led to a search for suitable alternatives to conventional therapy. Quinolones have been found to be an effective alternative for the treatment of MDRST, in adults as well as in children.

METHODS

The efficacy of various therapeutic regimens currently used for the treatment of Typhoid was analysed. Children 1 month to 12 years of age admitted to the Children's Hospital from 1990 to 1993 with fever and Salmonella typhi isolated from blood cultures were included in this retrospective analysis.

RESULTS

The cumulative prevalence of Multiple Drug Resistant Salmonella typhi (MDRST) was 67.2%. Only 32.8% of isolated Salmonella typhi were susceptible to chloramphenicol and amoxicillin. The cumulative cure rate with conventional therapy (chloramphenicol or amoxicillin) was 47.4% and 53.6% children needed a change of therapy. The average hospital stay for the non-responders to conventional therapy was 9.2 days as compared to 7.7 days for the responders. The average hospital stay of the patients treated with a third generation cephalosporin was 12.7 days. Patients treated with ofloxacin, a flouroquinolone drug, did not need a change of therapy. The average hospital stay of the patients treated with flouroquinolones was 6.2 days.

CONCLUSION

There was a high prevalence of multiple drug resistant typhoid fever in hospitalized children, leading to a high failure rate with conventional therapy. This resulted in frequent change of therapy, delayed defervesence and prolonged hospital stay. The flouroquinolones were found to be the most effective drug against MDRST.

Fat absorption in persistent diarrhoea using 13C-labelled trioctanoin breath test

A study was undertaken to investigate intestinal fat absorption in young children suffering from persistent diarrhoea in comparison with normal children of similar age. Absorption studies were performed using the breath test technique. Following oral administration of labelled triglyceride ([13C]trioctanoin), interval breath sampling was done for 6 h. The time course of excretion of 13CO2 in the breath was determined by isotope ratio mass spectrometric analysis of the gas samples. Excretion curves were constructed from the mean values of 13CO2 dose (per cent) excreted at each time point in breath samples and areas under the curve were determined for diarrhoea cases as well as for normal subjects. The time course of 13CO2 excretions and areas under the curve thus obtained were compared with each other and also with a reference study in which data from known malabsorption cases were available. The time of peak 13CO2 excretion in diarrhoea cases ranged from 60 to 240 min (average 150 min) compared with 120 to 270 min (average 195 min) for normal subjects, the level of peak of 13CO2 excreted/h was 4.8 +/- 1.2 per cent in diarrhoea cases and 5.3 +/- 2.3 per cent in normal children (NS). Mean areas under the curve for the two groups were 18.9 +/- 3.4 per cent for normal and 17.6 +/- 4.1 per cent dose 13CO2 excreted/6 h for diarrhoea cases (NS). These results indicate that intestinal absorption of medium chain triglycerides was not impaired significantly in the cases of persistent diarrhoea studied.

Dexamethasone and bacterial meningitis in Pakistan

The objective of this study was to assess, in a developing country setting, the effect of dexamethasone therapy on bacterial meningitis outcomes. A prospective double blind placebo controlled trial was conducted in 89 children aged from 2 months to 12 years suffering from bacterial meningitis. Neurological, developmental, and hearing assessments were conducted at one, four, and 12 months after discharge. Forty eight patients received dexamethasone and 41 placebo. Initial antimicrobial drugs used were ampicillin and chloramphenicol. For all patients at the time of admission the mean duration of illness was 5.7 days; 47% had had seizures and 56% had impaired consciousness. Seventeen of 89 (19%) patients died. The mortality for the dexamethasone group was 25% as compared with 12% in the group receiving placebo. Presentation to the hospital after four days of symptoms and with impaired conscious state were independent predictors of death. Of the dexamethasone group survivors, 26.5% had neurological sequelae and 42.3% had hearing impairment, whereas in the placebo group it was 24% and 30% respectively. Altered state of consciousness was a predictor of neurological sequelae. The presence of neurological sequelae and high cerebrospinal fluid protein independently predicted hearing loss. No beneficial effect of dexamethasone was observed on morbidity or mortality of this group of patients with bacterial meningitis. Dexamethasone is therefore not useful in developing countries as adjunctive treatment in patients seriously ill with bacterial meningitis, who present late for treatment and have been partially treated.

Clinical profile of acute rheumatic fever in children

A prospective study was done to determine the clinical profile of acute rheumatic fever in the first attacks and in recurrences separately. The data were compared with those from other countries. Eighty children were in their first attack while 46 had recurrences. Arthritis, the most common manifestations, was seen in 61 per cent of patients with first attack followed by carditis in 41 per cent, chorea in 28 per cent and subcutaneous nodules in 3 per cent. However, in the recurrences, arthritis was present in 52 per cent, carditis in 81 per cent, chorea in 11 per cent, and nodules in 4 per cent of cases. In both the groups, no case with erythema marginatum was seen. The results show that in the first attack the clinical picture broadly resembles that in European and North American countries. The presenting symptoms and signs are different during recurrence.

The medical assessment of mentally retarded children in hospital

Most subnormal patients in hospitals are not there because they require active hospital treatment. Leck, Gordon and McKeown (1967), Pilkington (1966) and Tizard (1964) have suggested that respectively 0·4 per cent, 10 per cent and 12 per cent of the hospitalized patients they studied were admitted as the result of medical advice, or were in need of ‘detailed specialist day to day diagnosis, care and treatment’. This study is part of a computer evaluation of medical data concerning 285 severely retarded children, admitted to hospital for very varying periods during 1964–1966. Altogether 375 admissions took place but of these 86 were readmissions, so there were 289 ‘primary’ admissions, 4 of whom had no traceable documentation, thus 285 (76 per cent) of the 375 admissions were studied.