Evidence for altered density characteristics of the peripheral blood lymphocytes in kwashiorkor

The immune system in children with malnutrition--a systematic review

BACKGROUND

Malnourished children have increased risk of dying, with most deaths caused by infectious diseases. One mechanism behind this may be impaired immune function. However, this immune deficiency of malnutrition has not previously been systematically reviewed.

OBJECTIVES

To review the scientific literature about immune function in children with malnutrition.

METHODS

A systematic literature search was done in PubMed, and additional articles identified in reference lists and by correspondence with experts in the field. The inclusion criteria were studies investigating immune parameters in children aged 1-60 months, in relation to malnutrition, defined as wasting, underweight, stunting, or oedematous malnutrition.

RESULTS

The literature search yielded 3402 articles, of which 245 met the inclusion criteria. Most were published between 1970 and 1990, and only 33 after 2003. Malnutrition is associated with impaired gut-barrier function, reduced exocrine secretion of protective substances, and low levels of plasma complement. Lymphatic tissue, particularly the thymus, undergoes atrophy, and delayed-type hypersensitivity responses are reduced. Levels of antibodies produced after vaccination are reduced in severely malnourished children, but intact in moderate malnutrition. Cytokine patterns are skewed towards a Th2-response. Other immune parameters seem intact or elevated: leukocyte and lymphocyte counts are unaffected, and levels of immunoglobulins, particularly immunoglobulin A, are high. The acute phase response appears intact, and sometimes present in the absence of clinical infection. Limitations to the studies include their observational and often cross-sectional design and frequent confounding by infections in the children studied.

CONCLUSION

The immunological alterations associated with malnutrition in children may contribute to increased mortality. However, the underlying mechanisms are still inadequately understood, as well as why different types of malnutrition are associated with different immunological alterations. Better designed prospective studies are needed, based on current understanding of immunology and with state-of-the-art methods.

The effect of nutritional support on T-lymphocyte subpopulations in protein calorie malnutrition

T-lymphocyte subpopulations were measured in the two major types of adult malnutrition, adult marasmus and kwashiorkor-like hypoalbuminemic malnutrition. The population of T-cells (T3) and the percentage of both helper (T4) and suppressor (T8) T-cells were significantly (P less than .05) decreased in patients with kwashiorkor-like hypoalbuminemic malnutrition, but did not differ from control values in patients with adult marasmus. The ratio of helper T-cell (T4), to suppressor T-cells (T8) (range 1.2-1.6) did not vary from control values in either type of malnutrition. One week of nutritional support was not associated with a significant increase in any of the T lymphocyte subpopulations in either type of malnutrition. These T-cell subpopulation changes are consistent with the greater depression of cellular immune function seen in patients with metabolic stresses associated with kwashiorkor-like hypoalbuminemic malnutrition. With the increasing frequency in which abnormalities of T-cell subpopulations are being reported in various diseases, the coexistence of kwashiorkor-like hypoalbuminemic malnutrition should be noted for its potentially confounding effect.

A clinical assessment of fluorescence polarisation changes in lymphocytes stimulated by phytohaemagglutinin (PHA) in malignant and benign diseases

The modified double-zone SCM technique, developed in these laboratories as an in vitro test for cancer, is based on the differential response to PHA of lymphocytes harvested from two regions of a Ficoll-Triosil gradient. Lymphocyte responses are measured by changes in intracellular fluorescein fluorescence polarisation. We report its continued clinical evaluation in patients hospitalised with malignant and non-malignant diseases, including a blind trial of 78 patients with disorders of the gastrointestinal tract, breast and lung. Overall "false' negative and "false' positive rates from 336 blood samples were 1.8 and 3.3% respectively.