Impact of parvovirus B19 infection in pediatric oncology patients

Oncology patients are at particular risk for parvovirus B19 infection that may cause severe, persistent usually non specific illness in this group. This study was designed to assess the prevalence and impact of parvovirus B19 in pediatric oncology patients receiving chemotherapy and to define the optimal diagnostic tests in such patients. Fifty nine children under chemotherapy [39 with ALL, 20 with solid tumors] with mean ages of 4.96 +/- 1.94 years, in addition to 30 healthy children of matched age and sex, were enrolled in this study. Clinical and laboratory data were collected by examination and from patients' records. Specific parvovirus IgM, and IgG B19 antibodies were assessed by Elisa and parvovirus DNA was detected by nested PCR for all patients and controls. Parvovirus DNA was detected in 16 [27.1%], IgM in 3 [5.1%] and IgG in 36 [61%] patients. IgM had sensitivity, specificity and accuracy of 18.75%, 100% and 77.9% respectively, while those of IgG were 81.25, 53.4%, 61% respectively. PCR positive patients had significantly higher frequency of unexplained anaemia, blood transfusions and longer hospital stay than PCR negative patients [P<0.001]. Multiple linear regression analysis showed that both unexplained anaemia and multiple blood transfusions were the most important variables that can predict PCR positivity. Parvovirus B19 is not uncommon problem in pediatric oncology patients that exhibited weak antibody response and non specific clinical features. Screening of these patients with PCR rather than serology is recommended when infection is suspected

Bone turnover markers and bone mineral status in protein-energy malnourished infants

This study aimed to evaluate bone turnover in malnourished infants and to assess their bone mineral status by dual energy x-ray absorptiometry [DXA]. We studied 18 marasmic patients aged 10.55 +/- 7.01 mo [mean +/- SD], 5 kwashiorkor patients aged 18 +/- 6 mo in addition to 7 healthy infants with matched age and sex. For all subjects, serum levels of osteocalcin, parathormone and bone specific alkaline phosphatase were assessed by Elisa and 25 [OH] D3 level by RIA. Urinary excretion of deoxypyridinoline was assessed by Elisa and expressed as nmol/mmol creatinine. Bone mineral content [BMC] and bone mineral density [BMD] were measured by DXA. Osteocalcin was significantly lower in marasmus and kwashiorkor group than control [P=0.02, 0.002]. Marasmus group had a significantly higher osteocalcin level than kwashiorkor [P=0.037]. Compared with control, deoxypyridinoline was significantly lower in marasmus than control [P=0.014] but was insignificantly lower in kwashiorkor with no significant difference between both patient groups. Alkaline phosphatase and parathormone were significantly lower in marasmus than control but not in kwashiorkor. There were no significant differences between the studied groups regarding 25[OH] D3. Bone mineral content was significantly lower in all of the studied regions of both patient groups than control and kwashiorkor patients had a significantly decreased arm and total BMC than marasmus [P=0.07, 0.02 respectively]. Only leg BMD was significantly lower in malnourished patients. There was no significant correlation between biochemical markers and total BMC or BMD. Protein-energy malnourished infants have decreased bone turnover which was more pronounced in marasmus with decreased BMC and non generalized decrease in BMD

Study of peripheral lymphocytes apoptosis in childhood tuberculosis

In a trial to understand some aspects of immunopathogenesis of active tuberculous infection in children, we studied the spontaneous and Mycobacterium tuberculosis [MTR]-induced apoptosis of lymphocytes in children with tuberculous infection. This study included 18 newly diagnosed tuberculous patients [11 pulmonary and 7 lymphadenopathy] with age range of 4-15 years [mean 10.7 +/- 3.1 y] in addition to 9 contacts with positive tuberculin test and 9 healthy tuberculin non-reactors with matched age and sex. Diagnosis of tuberculosis was confirmed by smear positivity, Bactec culture for T.B or biopsy. From each patient and control peripheral blood mononuclear cells [PBMC] were obtained and subjected to study of apoptosis both spontaneously and after stimulation with atypical mycobacterial culture by TUNEL Method. The mean percentages of spontaneous apoptosis were 7.83 +/- 3.29, 1.22 +/- 0.44 and 1.0 +/- 0 in tuberculous patients, tuberculin positive contacts and healthy negative control respectively. After culture, the mean percentages of apoptosis increased to 16 +/- 7.15, 4.77 +/- 1.85 and 2.33 +/- 0.71 in patients, tuberculin reactor contacts and healthy non- reactor groups respectively. Spontaneous apoptosis was significantly higher in patients than contact tuberculin-reactors and healthy non reactors [P<0.001] without significant difference between the latter 2 groups. After culture, apoptosis in patients was significantly higher than control groups [P < 0.001] and tuberculin reactor contacts had significantly more apoptosis than healthy non reactors [P=0.002]. There was no significant difference in apoptosis increment between pulmonary or tuberculous lymphadenopathy patients. There was highly significant correlation between tuberculin diameter and incremement of apoptosis [P=0.006]. It could be concluded that apoptosis is directly involved in the immunopathogenesis of tuberculosis in children. It affects both primed and non primed lymphocytes and is related to the state of hypersensitivity