The current study analyzed the differences between pediatric and adult celiac disease, and the obtained results showed that pediatric and adult celiac disease is characterized by a female predominance in all age groups with a gender ratio of 1.62. This predominance was also suggested by other studies (
12,
13). In the present series, the mean age of celiac patients was 15.17 ± 15.76 years. The mean age at disease diagnosis was 10.79 ± 10.72 and 21.07 ± 12.49 years in children and adults, respectively. This issue is confirmed by other studies (
14), as the disease can be diagnosed at any age. Therefore, the starting age for the gluten-free diet was 9.23 ± 9.93 years in all patients and 1.80 ± 0.68 years in infants. This suggests that the development of the disease is related to the cessation of breastfeeding and the early introduction of cereals containing gluten, confirmed by Poddar’s study results (
6).
The mean BMI in the current sample was 15.79 ± 2.47 kg/m
2; all the patients were malnourished (BMI < 16.5 kg/m
2). This finding is similar to the findings of other studies conducted on Indian children indicating that growth retardation was a frequent manifestation of the disease (
6). In a comparable way to adults, the present study’s results demonstrated an increase in the rate of BMI (> 16.5 kg/m
2) comparable to a study by Dickey and Kearney (
15), who showed that few celiac patients were underweight at diagnosis.
The clinical symptomatology of the disease was characterized by classic forms that are defined as digestive disorders, which were predominant in children (69%), mainly chronic diarrhea (54.1%), abdominal pain (63.3%), and abdominal bloating (32.1%), with a significant difference (P = 0.004; P = 0.026, and P < 0.001, respectively), which is consistent with a study by Rodrigo-Saez et al. (
16) who noted that chronic diarrhea was the main feature of the disease in children. On the other hand, adults also expressed chronic diarrhea as the main symptom of the disease. The current study’s results are confirmed by Sood et al.’s study (
17), in which chronic diarrhea was present in adults, in contradiction with other studies’ results (
18). Therefore, the present study’s results underline that extra digestive manifestations are quite common in adults with celiac disease, such as weight loss (52.7%), anemia (51.4%), and asthenia (37.8%), with a significant difference (P = 0.004, P = 0.026, and P = 0.026, respectively). The current study’s results are suggested by several compliance studies (
6). Although weight loss was the principal extra digestive manifestation (P = 0.004) in the infant group, the stature weight delay was dominant in children (P = 0.016). The aforementioned data are similar to those of Vivas et al.’s study (
18).
In the present study, there were many diseases associated with celiac disease in children and adults; however, in the adult group, Crohn’s disease and hypothyroidism seem to be more frequent, as noted in the results of studies by Doya et al. (
19) and Baharvand et al. (
20). Rodrigo-Saez et al. (
16) suggested that most associated diseases in adults are of autoimmune origin. Unlike in the infant group, where allergy was followed by anemia as the main associated disease, Vivas et al. (
18) suggest that anemia is one of the associated diseases in infants and children. Anemia, hypothyroidism, and type 1 diabetes were the main associated comorbidities confirmed by the results of El Mehadji et al.’s study (
21). In addition, the literature has shown that celiac disease is associated with autoimmune diseases, mainly type 1 diabetes and hypothyroidism (
22,
23).
The serological tests were necessary for the diagnosis of the disease, although the current study’s results showed that serology was positive in 85.2% of celiac patients. The present study’s results are similar to the results of other studies (
21,
24), recalling that even in infants (90.0%), children (80.7%), and (89.2%) adults, the tests mainly (IgA and IgG a-tTG, IgA endomysial antibodies, and IgA antigliadin antibodies) were significantly higher for children than adults, which underlines an excellent predictive value to confirm the diagnosis (
25,
26). A study by Roujon et al. (
24) showed that anti-endomysium and tissue transglutaminase IgA antibodies represent the most specific and sensitive markers, with the exception of IgA-deficient patients. Further search for IgG is recommended. The present study’s results are concordant with other studies' results (
27) concerning the use of anti-transglutaminase assays. Nevertheless, the present study showed a significant difference in anti-transglutaminases of IgG (P < 0.001).
The histological test defined by a duodenal biopsy remains an examination of reference to confirm the diagnosis of celiac disease. That is why all the studied patients underwent a biopsy with the presence of villous atrophy of partial grade (Marsh = 3), which was dominant in all the patients. Moreover, the total grade (Marsh ≥ 3) was present in adults more frequently than in children. The aforementioned results were also reported by other studies (
21,
27).
The response to the gluten-free diet is also necessary to confirm the diagnosis of celiac disease (
26). Therefore, good adherence to the gluten-free diet was higher in children than in adults, with a significant difference (P = 0.001), which is consistent with another study’s results (
28). Poor adherence to the gluten-free diet and/or lack of clinical and histological response favors the development of refractory sprue, as confirmed by Leffler et al. (
28) and Abdulkarim et al. (
29).
5.1. Conclusions
Celiac disease in the western Algeria region presents many differences between children and adults. In adults, the presentation of the disease is marked during childhood and is characterized by the presence of atypical and typical forms. Additionally, comorbidity was in the form of autoimmune diseases in adults. Adherence to the gluten-free diet has been well established in children than adults.