Age-dependent histoarchitectural changes in human lymph nodes: an underestimated process with clinical relevance?

Experimental evidence indicates that lymph nodes in humans undergo alterations during ageing. This is clinically important because of the crucial role of these organs in the immune system and their lymph reabsorption and drainage function. Although some age-related changes in lymph node histoarchitecture have been described, they are seldom taken into account in traditional depictions of lymph nodes. Recently introduced clinical procedures, such as intranodal vaccination or lymph node transplantation, have demonstrated the need for an accurate knowledge of these degenerative processes. In this study, superficial inguinal lymph nodes were obtained from 41 deceased patients between 17 and 98 years old. To minimize immunological influences, such as chronic diseases, specimens were only obtained from forensic pathology autopsies. An immunohistochemical analysis was carried out, on the basis of which lymph node degeneration was scored according to the numbers of lymphocytes and high endothelial venules, and degree of fibrosis and lipomatosis. We observed an age-dependent tendency towards the replacement of areas populated with diverse immune cells by connective tissue. Paradoxically, these changes were also detected in some of the nodes from younger age groups. In conclusion, lymph nodes can display degenerative changes that are mainly age-related and often diverge from the common description found in textbooks. These alterations should be taken into account when dealing with lymph nodes diagnostically and therapeutically in clinical practice.

The German case-control scene investigation study on SIDS: epidemiological approach and main results.

The present study, which was part of the German SIDS Study (GeSID), enrolled sudden infant death syndrome (SIDS) cases and population controls and obtained objective scene data via specifically trained observers shortly after discovery of each dead infant. Infants who had died suddenly and unexpectedly at ages between 8 and 365 days were enrolled in five regions of Germany between November 1998 and October 2001. Shortly after discovery of each dead infant, a specially trained doctor of legal medicine visited the bereaved family at home. Data were obtained by measurements and observations. Dead infants underwent a standardised autopsy, additional information being obtained by standardised parent interviews. Investigation of the sleep environment and wake-up scene in matched controls followed the same protocol. A total of 52 SIDS cases and 154 controls were enrolled, 58% were boys, and median age of cases vs. controls was 126 vs. 129 days. Risk factors in the sleeping environment were pillow use (adjusted OR 4.3; 95%CI 1.6-11.6), heavy duvets (OR 4.4; 1.5-13.3), soft underlay (OR 3.0; 1.1-8.7), face covered by bedding (OR 15.8; 2.5-102.1) and entire body covered by bedding (OR 35.5; 5.5-228.3). Using a standardised protocol, including objective measurements of the sleep environment and a case-control design, this study was able to confirm many risk factors for SIDS.

Age-dependent development of the splenic marginal zone in human infants is associated with different causes of death.

Infants are more susceptible to infections caused by T cell- independent type 2 (TI-2) polysaccharide antigens of certain encapsulated bacteria. Immune responses against this type of antigen are related to the splenic marginal zone (MZ). However, only few data exist on the age-dependent developmental stages of the human spleen in early childhood and on their association with different diseases. Therefore, the present study aimed to investigate spleens of a large number of children at very young ages (12 days to 32 months), derived from autopsy cases. Immunohistochemical labeling was performed on paraffin sections of 34 spleens using a panel of monoclonal antibodies. The shape and size of the white pulp compartments were examined and correlated to the cause of death of the children. Results show that the development of the different compartments was statistically age-dependent, but no clear-cut time point for the maturity of each compartment was seen. Furthermore, the MZ was significantly more often missing when sudden infant death (SID) and/or infection were the cause of death, compared with other violent or traumatic reasons that served as controls. This association supports the concept that an immature state of the spleen and especially of the MZ might contribute to the increased susceptibility to bacterial infections in young infants.