AIM To study the occurrence of L-forms of H.pylori infectionin patients with peptic ulcers and its assodation with possiblechanges of cellular immune function in the patients.METHODS:Endoscopic biopsy specimens of gastric antrumand gastric corpus were taken from 228 patients with pepticulcers and inoculated into Skirrow selective medium for H.pylorivegetative forms and special medium for H.pylori L-forms,followed by bacterial isolation and identification.Andperipheral venous blood of the patients was taken to detectthe percentage of CD3~+,CD4~+ and CD8~+ with biotin-streptavidin(BSA)and the level of IL-2,IL-6 and IL-8 with ELISA.RESULTS:(1)The detection rates of H.pyloriL-forms andvegetative forms in the patients were 50.88 %(116/228)and 64.91%(148/228)respectively,and the co-infectionrate of H.pylori L-forms and vegetative forms was 78.38 %(116/148).To be more exact,the detection rates of H.pyloriL-forms in male and female patients were 57.04 %(77/135)and 41.94 %(39/93)respectively,and statistics foundsignificant difference between them(P<0.05).Furthermore,the detection rates of H.pyloriL-forms in patients aged 14years-,30 years-,40 years-and 50 years-were 31.91%(15/47),42.86 %(24/56),56.94 %(41/72)and 67.92 %(36/53)respectively,and there was significant differencebetween them(P<0.01).(2)The percentages of CD3~+,CD4~+,CD8~+,the ratio of CD4~+/CD8~+,and the level of IL-2,IL-6,IL-8 in H.pylori-positive patients were(52.59±5.44)%,(35.51±5.74)%,(27.77±8.64)%,(1.56±0.51),(2.66±0.47)mg/L,(108.62±5.85)ng/L and(115.79±7.18)ng/Lrespectively,compared with those in H.pylori-negativepatients,the percentages of CD3~+,CD4~+ and the ratio ofCD4~+/CD8~+ decreased,but the level of IL-2,IL-6 increased,and the difference was significant(P<0.001-P<0.01).Moreover,the percentages of CD3~+,CD4~+,CD8~+,the ratioof CD4~+/CD8~+,and the level of IL-2,IL-6,IL-8 in the patientswith mixed infection of both H.pylori L-forms and vegetativeforms were(51.69±5.28)%,(34.75±5.89)%,(27.15±7.45)%,(1.48±0.47),(2.16±0.38)mg/L,(119.45±5.44)ng/L and(123.64±6.24)ng/L respectively,compared with those inpatients with simple infection of H.pylorivegetative forms,the percentage of CD4~+,the ratio of CD4~+/CD8~+ and thelevel of IL-2 increased,but the level of IL-6 and IL-8decreased,statistical difference was found between them(P<0.001-P<0.05).CONCLUSION:L-forms variation often occurs in patientswith peptic ulcers who are infected by H.pylori,which is commonly found in male patients and related to ages.TheL-forms variation of H.pylori can be an important factorcausing disorder of cellular immune function in the patientswith peptic ulcers who are infected by H.pylori. AIM To study the occurrence of L-forms of H. pylori infectionin patients with peptic ulcers and its assodation with possiblechanges of cellular immune function in the patients. METHODS: Endoscopic biopsy specimens of gastric anpathy gastric corpus were taken from 228 patients with pepticulcers and inoculated into Skirrow selective medium for H. pylorivegetative forms and special medium for H. pylori L-forms, followed by bacterial isolation and identification. Endperipheral venous blood of the patients was taken to detect the percentage of CD3 ~ +, CD4 ~ + and CD8 ~ (1) The detection rates of H. pylori L-forms and vestigial forms in the patients were 50.88% (116 / 228) and 64.91% (148/228) respectively, and the co-infection rate of H. pylori L-forms and vegetative forms was 78.38% (116/148). To be more exact, the detection rates of H. pylori L-forms in male and female patients were 57.04% (77/135) and 41.94% (39/93) respectively, an Fluorrthermore, the detection rates of H.pylori L-forms in patients aged 14years-, 30 years-, 40 years-and 50 years-were 31.91% (15/47), 42.86 % (24/56), 56.94% (41/72) and 67.92% (36/53) respectively, and there was significant difference between them (P <0.01). (2) The percentages of CD3 ~ +, CD4 ~ The ratio of CD4 ~ + / CD8 ~ +, and the level of IL-2, IL-6 and IL-8 in H.pylori-positive patients were (52.59 ± 5.44)%, (35.51 ± 5.74) %, (27.77 ± 8.64)%, (1.56 ± 0.51), (2.66 ± 0.47) mg / L, (108.62 ± 5.85) ng / L and (115.79 ± 7.18) ng / L respectively, compared with those in H.pylori- negative patients, the percentages of CD3 +, CD4 + and the ratio of CD4 + / CD8 + decreased, but the level of IL-2, IL- 6 increased, and the difference was significant (P <0.001- ) .Moreover, the percentages of CD3 ~ +, CD4 ~ +, CD8 ~ +, the ratio of CD4 ~ + / CD8 ~ +, and the level of IL-2, IL- 6, IL- 8 in the patients with mixed infection of both H.pylori L-forms and vegetativeforms were (51.69 ± 5.28)%, (34.75 ± 5.89)%, (27.15 ± 7.4 5)%, (1.48 ±0.47), (2.16 ± 0.38) mg / L, (119.45 ± 5.44) ng / L and (123.64 ± 6.24) ng / L respectively, compared with those inpatients with simple infection of H.pylorivegetative forms, the percentage of CD4 ~ , the ratio of CD4 ~ + / CD8 ~ + and the level of IL-2 increased, but the level of IL-6 and IL-8 decreased, statistical difference was found between them (P <0.001-P < -forms variation often in patients with peptic ulcers who are infected by H. pylori, which is commonly found in male patients and related to ages.The L-forms variation of H. pylori can be an important factorcausing disorder of cellular immune function in the patientswith peptic ulcers who are infected by H.pylori.