Role of 30 kDa antigen of enteric bacterial pathogens as a possible arthritogenic factor in post-dysenteric reactive arthritis.

Background: Reactive arthritis (ReA)/Reiter’s syndrome (RS) may be caused as a sequel of infections caused by enteric bacterial pathogens, although the mechanisms through, which different pathogens cause similar disease are not clear. Aim: This study was done to look for the presence and role of any common bacterial antigen among the pathogens isolated from such patients. Materials and Methods: A total of 51 patients of ReA and 75 controls (three groups of 25 subjects each: Group 1: Patients who did not develop arthritic complications within 3 months after bacillary dysentery/diarrhea; Group 2: Patients with other arthritic diseases and Group 3: Normal healthy subjects) were included. The isolated enteric pathogens were tested to detect the immunodominant antigens. Results and Conclusions: A common 30 kDa antigen was found to be specifi cally present among seven arthritogenic enteric bacterial strains belonging to three genera, Salmonella, Shigella and Hafnia. Post-dysenteric ReA patients’ sera show higher levels of immunoglobulin G, immunoglobulin M and immunoglobulin A antibodies against this antigen as compared to the controls. Lymphocytes of ReA patients recognize this antigen, proliferate and produce interleukin-2 in response to this antigen more than the lymphocytes of controls. 30 kDa antigen may be a common arthritogenic factor associated with postdysenteric ReA/RS. The association of Hafnia alvei with post-dysenteric ReA is described for the fi rst time. Four cases of mycobacterial ReA had an association with this antigen, suggesting that the arthritogenic antigen of mycobacteria and enteric bacteria may be of a similar nature.

Wheat threshing dust--a "new allergen" in April-May nasobronchial allergy.

OBJECTIVE: To identify the allergen(s) responsible for mid April-mid May nasobronchial allergy seen in North India. DESIGN: Case control study. SETTING: Children living in and around Chandigarh (urban, rural). SUBJECTS: 39 children suffering from wheat harvest period (mid April-mid May) respiratory allergy along with randomly selected controls. METHODS: Aerobiological surveys were done from March to June for identification of prevailing allergens for performing allergy tests. Patients were subjected to skin tests (ST), nasal provocation tests (NPT) and bronchial provocation tests (BPT) with extracts prepared from identified pollens and fungal spores. Specific IgE (SIgE) was assayed by ELISA and comparison between pre-season, season and post-season values made. RESULTS: 81% patients had ST positive to antigen of wheat threshing dust (WTD), 30% to fungal antigens, 14% to wheat dust antigens and none to the wheat plant (WP) antigens. Nasal provocation test and bronchial provocation tests were also positive to WTD in 80% and 66% patients, respectively. WTD SIgE was demonstrated in 77% of ST positive patients. CONCLUSIONS: These in vivo and in vitro tests confirm wheat threshing dust as a major causative inhalant allergen for the April-May nasobronchial allergy; in addition, fungal allergens also play a role in 1/3rd of these patients.

Body water distribution in newborn infants appropriate for gestational age.

Total body water (TBW), extracellular water (ECW) and intracellular water (ICW) were measured within 6 h of birth in 99 appropriate for gestational age (AGA) infants. The two groups of infants included were term (mean +/- SD gestation 272 +/- 7 days) and preterm (mean +/- SD gestation 238 +/- 11 days) infants. The mean TBW +/- SD was 777 +/- 26 ml/kg in preterm infants and 737 +/- 26 ml/kg in term infants. The corresponding ECW was 349 +/- 26 ml/kg and 331 +/- 30 ml/kg respectively. Weight was the best correlate of TBW (r = 0.98) and ECW (r = 0.92) volumes. TBW per unit of body weight showed significant decline with increasing gestation (r = -0.54) and birth weight (r = -0.51). ICW per kg showed a moderate correlation with TBW (r = 0.63), whereas ECW per kg had a low correlation (r = 0.35) with it. TBW/kg in our infants was comparable to infants from other ethnic groups. ICW/kg, however, was consistently higher and ECW/kg lower at all stages of maturation in Indian infants as compared to Caucacian and Negroid infants.

Water electrolyte homeostasis in acute bronchiolitis.

Children with acute bronchiolitis frequently require hospitalization and parenteral fluid therapy. Water retention due to impaired renal water excretion has been described in several pulmonary conditions in children. We studied 20 infants (3.6 +/- 2.9 months), hospitalized consecutively for acute bronchiolitis for water and electrolyte changes during the acute stage and compared them to those on recovery. Serum sodium and plasma osmolality, urinary sodium and osmolality were measured in all infants. Ten infants each were assigned alternatively to study body water compartment or renal water handling (water load excretion and free water excretion capacity) on the day of hospitalization and after recovery. Mean ( +/- SD) value of serum sodium of the infants at admission was 132.7 +/- 7.2 mEq/L which increased to 137.1 +/- 5.4 mEq/L on recovery (p < 0.05). Plasma osmolality changed from 284 +/- 14 mOsm/kg at admission to 294 +/- 10 mOsm/kg at recovery (p < 0.05). There was a significant decrease in urinary sodium from 54 +/- 39 mEq/L to 20 +/- 18 mEq/L and urinary osmolality from 415 +/- 213 mOsm/kg to 252 +/- 204 mOsm/kg at admission and at recovery, respectively. All 10 infants showed significant increase in total body water (mean +/- SD; 22.8 +/- 7.5 ml/kg) at admission as compared to that at recovery. The total body water (TBW) excess was mainly in extracellular water compartment (16.3 +/- 3.6 ml/kg). Seven of 10 infants had significant impairment in renal water excretion. Increase in maximum free water clearance of these 7 infants on recovery was 0.69 +/- 0.27 ml/min, i.e., 15 times more than that at admission. It is concluded that bronchiolitis of infancy is characterized by water retention which is caused by impaired renal water excretion. In the management of severe bronchiolitis careful attention to fluid therapy is mandatory; liberal fluid therapy may lead to water intoxication.

Bacterial contamination of reconstituted oral rehydration solution.

The extent and nature of bacterial contamination in oral rehydration solution reconstituted for use by individuals and for group of patients was studied. Twenty three volunteers (all qualified doctors) were asked to reconstitute a packet of prepackaged salt in half litre of clean unboiled water obtained from taps at their residence. Five ml aliquots of ORS were collected at 6, 12 and 24 hours after reconstitution for bacteriologic study. The water used by volunteers to reconstitute the ORS as well as throat swabs, peri-anal swabs and nail clippings of volunteers yielded pathogenic bacteria in all the subjects/samples. All the 23 specimens of ORS prepared by volunteers when cultured at 6 hours after reconstitution yielded pathogenic bacteria. The bacterial colony counts were found to be unacceptably high at 12 hours. Five ml samples of reconstituted ORS prepared in bulk in the children ward of PGIMER, Chandigarh were cultured at 12, and again at 24 hours after reconstitution on 10 different days. These yielded Klebsiella pneumoniae in 8 specimens (80%) and E. coli in 2 (20%). The bacterial colony count was unacceptably high, 12 hours after reconstitution.