Predictive role of laboratory markers and clinical features for recurrent Henoch-Schönlein Purpura in childhood: A study from Turkey.

Objectives: Henoch Schönlein Purpura is the most common systemic vasculitis of the childhood. The objective of this study was to evaluate whether there is a clinical significance of laboratory parameters and clinical features on the prediction of the recurrent Henoch Schönlein Purpura in children.Methods: For recurrent Henoch Schönlein Purpura, several laboratory results and clinical features were examined to identify the predictor factors via the logistic regression model in 99 children with Henoch Schönlein Purpura. A p-value of <.05 was considered significant. The patients were divided into two groups as the first attack and the recurrent.Results: The demographic features and laboratory results were not found statistically significant between the two groups (p > .05). The multiple logistic regression model showed that the risk of recurrent Henoch Schönlein Purpura increased 17.2-fold in children with Henoch Schönlein Purpura affected by the four systems including skin, joint, kidney and gastrointestinal system [Odds Ratio (OR) 17.2, 95% CI 1.4-12; p < .001].Conclusion: In our inpatient population, the laboratory characteristics were detected not to be a factor for the prediction of recurrence. However, the four systems including skin, joint, kidney and gastrointestinal involvement may be used as a predictive factor for recurrent HSP.

Pertussis serosurveillance study in Izmir, Turkey.

Pertussis is a life-threatening, vaccine-preventable infection. Adults who can be asymptomatic may infect infants. The aim of this study is to determine the IgG antibody levels against pertussis toxin (PT) and filamentous hemagglutinin from 6 months to ≥60 years in Izmir, Turkey. A cluster sample design developed by Expanded Programme on Immunization of the World Health Organization was carried out for the selection of the study population, which consisted of 399 healthy subjects. In-house ELISA was studied in Turkish Public Health Institution. Antibody levels of <10 EU/ml, ≥10 EU/ml and ≥100 EU/ml were accepted as non-immune, immune and possible acute/recent infection, respectively. Anti-PT antibody levels were 8.5% <10 EU/ml, 68.2% 10-100 EU/ml and 23.3% ≥100 EU/ml; the latter was correlated with possible acute/recent infection. Results showed that pertussis is endemic, particularly among adolescents and adults, which is a threat for infants who have not completed their primary immunization.

[Detection of Bordetella pertussis infection by culture, real-time polymerase chain reaction and serologic tests among children with prolonged cough]. / Uzamis Öksürügü Olan Çocuklarda Kültür, Gerçek Zamanli Polimeraz Zincir Reaksiyonu ve Seroloji ile Bordetella pertussis Enfeksiyonunun Arastirilmasi

Pertussis is a respiratory infection caused by Bordetella pertussis. It attacks all age groups. It has significantly higher mortality and morbidity among newborns and children. Adolescents and adults with symptomatic but unrecognized pertussis are often the source of the infection for pediatric cases. Therefore, it is suggested to perform laboratory diagnostic tests for B.pertussis infection in children and adolescents with prolonged cough of more than two weeks. In this study, it was aimed to identify B.pertussis infection by culture, real-time polymerase chain reaction (Rt-PCR) and serological methods among children with prolonged cough. Nasopharyngeal swab samples were obtained from 51 children (19 female, 32 male; age between 2 months-14 years; median age: 7.0), who attended the outpatient clinic of Ege University Medical Faculty Department of Pediatrics, Izmir, Turkey with prolonged cough (≥ 14 days) during December 2009-August 2010. While pertussis vaccination had been completed in 48 (94%) of the cases, three cases had not been vaccinated. Previous antibiotic treatment was reported for 38 (75%) of the cases. Cultivation was done by using 7% horse blood and charcoal containing Bordetella Agar (Becton Dickinson, Germany) and Rt-PCR targeting IS481 sequence (Roche Applied Science, Germany) was used to detect B.pertussis. In addition, in house ELISA was performed to detect titers of anti-pertussis toxin (anti-PT) IgG and anti-filamentous hemagglutinin (anti-FHA) IgG antibodies in paired sera collected in 2-4 week intervals. Fourfold titer increase of antibodies or anti-PT IgG levels of at least 100 EU/ml in one serum were evaluated as serological confirmation of B.pertussis infection. In our study, B.pertussis was isolated from one nasopharyngeal swab samples culture among the 51 patients, and IS481 Rt-PCR yielded positive results for B.pertussis in 6 (11.8%) samples. Nine (17.6%) patients were diagnosed as B.pertussis infection by serological tests. Totally 12 patients were evaluated as positive using at least one method. Among them only one had positive results with three of the tests used and two were positive with IS481 Rt-PCR assay and serologic tests. Three patients were found positive with only IS481 Rt-PCR and six were identified only with serologic diagnosis. In this study, 23.5% (12/51) of children with persistant cough were evaluated as having B.pertussis infection. The age range of these cases (5 female, 7 male) was 2 months-11 years and one case had not been vaccinated at all while four cases had not completed the vaccination schedule. It was concluded that since B.pertussis can be detected as the etiologic agent of persistant cough in a significant number of children by culture, PCR and serologic tests, diagnostic tests must be applied to evaluate B.pertussis infection. However, standardized serological methods and PCR protocols are needed for accurate and reliable diagnosis.

Seroepidemiology of varicella-zoster virus and reliability of varicella history in Turkish children, adolescents and adults.

This study aimed to assess the age specific varicella-zoster virus (VZV) seroprevalence in Izmir, Turkey and to determine the reliability of a history of varicella to detect susceptible children, adolescents and adults. A questionnaire, including previous history of varicella, was completed for each participant and, in 590 of them, VZV-specific IgG was measured using an ELISA test. Overall, 28.5% of individuals were seronegative for VZV. By 5 years of age, only 25.5% of children were seropositive for VZV. Among adolescents and young adults, 18.8% and 11.7% were seronegative, respectively. The negative predictive value was 57.8%, decreasing with age (81.9% in children, 34.5% in adolescents and 8.3% in adults). In conclusion, a negative history of varicella is not a reliable predictor of varicella antibody status in adolescents and young adults. Serological testing before immunisation will be logical, rather than presumptive vaccination, for adolescents and adults with negative history of varicella.

The Association of minor congenital anomalies and childhood cancer.

BACKGROUND: Although the association of some congenital malformations and specific genetic syndromes is well understood, the association between minor anomalies and cancer is not well known. In recent years some researchers have reported studies establishing this association in different types of cancer. In this study, we aimed to investigate the prevalence and patterns of age-independent minor anomalies in childhood cancer patients. PROCEDURE: Two hundred patients with various types of cancer and 200 healthy controls were examined by two different medical geneticists for minor anomalies who evaluated all the cases and controls simultaneously. Besides minor anomalies, information on the consanguinity between the parents and occurrence of cancer in relatives were also recorded. The types of minor anomalies in different types of cancer, the number of minor anomalies in patients and controls, the association between cancer and the occurrence of different types of minor anomalies were also evaluated. RESULTS: The consanguinity and the history of cancer in relatives were significantly more prevalent in patients (P = 0.04 and P < 0.001, respectively). The number of minor anomalies in patients were significantly higher compared to the controls (P < 0.01). Particularly, the presence of hypertelorism, high-arched palate (approximately 40-fold higher, 95% CI: 12.895-125.037) and hand-foot anomalies were found to be more prevalent in patients having cancer compared to the controls. CONCLUSION: The common pathways during the embryogenesis may play a role in the development of cancer. The presence and the combination of minor anomalies seem to be associated with a higher prevalence of cancer.

Multicenter prospective study on the burden of rotavirus gastroenteritis in Turkey, 2005-2006: a hospital-based study.

Rotavirus is the main cause of gastroenteritis and dehydration requiring hospitalization among infants and children. Despite the high diarrhea-related mortality rate, there are limited studies describing the prevalence of rotavirus in Turkey. The disease burden of rotavirus gastroenteritis in Turkey was assessed by active, prospective surveillance conducted in accordance with a modified World Health Organization generic protocol from 1 June 2005 through 1 June 2006. A total of 411 children aged <5 years who were hospitalized for gastroenteritis in 4 centers were enrolled. Rotavirus was identified in 53% of samples from the 338 children tested; the range for individual centers was 32.4%-67.4%. Overall, 83.8% of rotavirus-positive children were aged <2 years. Rotavirus gastroenteritis occurred year-round but peaked in the winter. G1P[8] was the most widely prevalent strain (76% of strains), followed by G2P[4] (12.8%). G9P[8] was reported in samples from 3.9% of children. These data support the need for a rotavirus vaccine in Turkey.

Seroprevalence of hepatitis B infection in the Turkish population in Northern Cyprus.

This study was conducted to determine the seroprevalence of hepatitis B virus (HBV) infection in the Turkish population in Northern Cyprus. The secondary aim of this study was to assess the impact of the universal infant hepatitis B vaccination program, which started in 1998. A total of 600 persons 1- to 30-years-old were selected for the study with cluster sampling. The information on sociodemographic characteristics was gathered for each participant and in 585 of them, hepatitis B surface antigen (HBsAg), anti-hepatitis B surface antigen antibody (anti-HBs) and anticore antibody (anti-HBc) were tested. The overall prevalence of anti-HBc and HBsAg carriage was 13.2% and 0.85%, respectively. Old age and low parental educational level were the major independent risk factors for HBV transmission. Seroprevalence of both anti-HBc and anti-HBs antibodies was similar in children 1-7 years of age. After 8 years of age, anti-HBc seroprevalence increased significantly with age, while anti-HBs prevalence decreased (p<0.001). Anti-HBc prevalence increased from 7.0% in children aged 1-7 years to 17.9% in persons aged 16-20 years. None of the children under 12 years of age were HBsAg-positive, while 1.9% of persons aged 16-20 years were HBsAg carriers. Anti-HBs seroprevalence exceeding 90% was found in the cohorts targeted by the routine hepatitis B vaccination program, whereas 36.4% of young adults aged 21-30 years were anti-HBs-positive. The study shows that universal infant hepatitis B immunization has a substantial impact on the immunity in children. However, prevalence of HBV infection is still high in adolescent and young adults in Northern Cyprus. Therefore, catch-up immunization for these groups will help to reduce hepatitis B transmission.

Determination of Lymphocyte Cytokinesis-Block Micronucleus Values in Apparently Healthy Children by means of Age and Sex.

The cytokinesis-block micronucleus (MN) assay on blood lymphocytes is one of the most important tests implemented in cytogenetics for the measurement of genotoxicity. For the purpose of biological dosing, it is crucial to know the spontaneous frequency of MN and its normal values in general population, especially in children, which are used for the population databases. In this study, MN levels were investigated in cytokinesis-blocked lymphocytes of 150 apparently healthy children aged 1 to 15. Our aim was to assess the variability of MN values according to age and sex. The mean MN frequency among boys was 3.69 ± 1.747‰ and 4.12 ± 1.867‰ in girls where there was no significant difference in relation to age and sex. However, when we separated age groups as 0-2 years, 3-5 years, 6-10 years, and 11-15 years, one-way ANOVA test showed significant association. Significance was obvious in the 0-2 years age group with the 3-5 years age group and 6-10 years age group. When we grouped our study population as 0-2 years and 3-15 years, the mean MN frequency among the 0-2 years age group was 2.85 ± 1.599‰ and 4.07 ± 1.867‰ in the 3-15 years age group which was also statistically significant. This difference may be attributed to age-related increase of close contact with environmental hazardous agents. In conclusion, normal values of MN obtained in this study will add valuable information in regard to update the current childhood population data and will act as a reference for further genotoxicity studies.

Bordetella Pertussis Infection in Hospitalized Infants with Acute Bronchiolitis.

OBJECTIVE: To assess the frequency of B. pertussis infection among young infants hospitalized with acute bronchiolitis and to determine whether B. pertussis infection affects the clinical course of acute bronchiolitis. METHODS: A total of 172 infants <6 months of age hospitalized with acute bronchiolitis were tested for B. pertussis and respiratory viruses with real-time PCR. Cases were divided into 2 groups according to B. pertussis positive or negative. Clinical parameters, clinical severity scores and laboratory characteristics of the pertussis-positive and pertussis-negative cases were compared. RESULTS: Bordetella pertussis infection was detected in 44 (25.6%) of the 172 infants hospitalized for acute bronchiolitis, and as co-infection with respiratory viral agents in 27 (61.4%) infants. Of the 44 pertussis-positive infants, only 17 (38.6%) experienced a paroxysmal cough, 13 (29.5%) had whooping and 15 (34.1%) had post-tussive vomiting. There was no significant difference between pertussis-positive and pertussis-negative infants according to Wang clinical score at admission (4.9 ± 1.5 vs. 5.2 ± 2.5; p = 0.689). The overall disease severity score was also similar between the two groups (6.5 ± 1.4 vs. 6.9 ± 1.6; p = 0.095). CONCLUSIONS: Bordetella pertussis infection is common in young infants hospitalized for acute bronchiolitis, mostly as co-infection with respiratory viruses. The clinical features of pertussis in the infants are not characteristic. Viral bronchiolitis and pertussis cases could not be differentiated by clinical findings. Co-infection with pertussis did not affect the clinical outcome in infants hospitalized with acute bronchiolitis.

Purine nucleoside phosphorylase deficiency in a patient with spastic paraplegia and recurrent infections.

Purine nucleoside phosphorylase deficiency is a rare autosomal recessive immunodeficiency disease. The characteristic features of the disease include severe T cell immune defects with recurrent infections, a failure to thrive, and progressive neurological findings. To date, 35 cases of purine nucleosidase phosphorylase deficiency have been reported worldwide. A 2-year-old female patient was hospitalized due to recurrent infections starting from 6 months and a fever that had continued for a month. The parents were first cousins. Physical examination showed a failure to thrive, herpetic lesions around the lips, painful lesions on the tongue and the buccal mucosa, lung infection, and spastic paraparesis in the lower extremities. She had motor and mental retardation. Laboratory tests revealed lymphopenia; low CD3, CD4, and CD8 counts; normal immunoglobulin levels; low uric acid; and very low purine nucleoside phosphorylase enzyme activity (1.4 nmol/h/mg; normal range, 490-1530). DNA sequencing of the purine nucleosidase phosphorylase gene revealed a missense homozygous mutation, a G to A transition at exon 4 position 64 (349G>A transition), which led to a substitution of alanine by threonine at codon 117 (Ala117Thr). Both parents were heterozygous for the mutation. This is the second purine nucleosidase phosphorylase deficient case to have been presented and carrying this mutation worldwide. Various antibiotics, antifungal drugs, and intravenous immunoglobulin were used to treat the infections during her 3 months. This form of treatment proved to be unresponsive, resulting in her subsequent death at 26 months of age.

Evidence of an association between mannose binding lectin codon 54 polymorphism and adenoidectomy and/or tonsillectomy in children.

Mannose binding lectin (MBL) is a calcium-dependent lectin that plays an important role innate immunity by activating the complement pathway. There have been a number of studies describing an association between the MBL genotype and disease susceptibility. MBL deficiency has been described as one of the factors leading to a number of infections in children with recurrent upper respiratory tractus infections (URTI). We hypothesized that MBL deficiency may be associated with recurrent URTI, which requires adenoidectomy and/or adenotonsillectomy. In this study to clarify this hypothesis we investigated whether there may be an association between two low producing MBL variants and adenoidectomy and/or tonsillectomy due to recurrent URTI in children. Blood samples were collected, adenoidectomy and/or tonsillectomy due to recurrent URTI and 50 controls (mean age 80.53 +/- 32.62 months). In all patients and controls codon 54 and codon 57 polymorphisms of the MBL gene were analyzed. None of the subjects from the patient group and control group carried codon 57 polymorphism of the MBL gene. The frequency of low-level MBL genotypes (AB and BB) for codon 54 polymorphism in the patient group was found to be significantly higher compared to the control subjects (55.7% versus 14%) (p<0.001). This study shows that the presence of low-level MBL alleles is associated with adenoidectomy and/or tonsillectomy caused by recurrent URTI in children.

Comparison of ELISA with shell vial cell culture method for the detection of human rotavirus in fecal specimens.

The aim of the study was to compare an enzyme immunoassay method with shell vial cell culture method for detection of rotavirus in fecal specimens. In addition, the correlation between laboratory results and clinical scores of patients with gastroenteritis was evaluated. A total of 219 fecal specimens from children (ages 3 weeks to 5 years) with acute gastroenteritis submitted to pediatric emergency room were evaluated by both ELISA and shell vial cell culture. A Vesikari score was used for assessing the severity of the illness. Among 219 stool samples tested, 107 (48.9%) were determined to be positive. Two specimens were positive by shell vial cell culture method while they were ELISA negative. According to these results the calculated sensitivity, specificity, PPV, and NPV of ELISA were 98.1%, 100%, 100%, and 98.2%, respectively. The mean severity score for the 107 episodes of rotavirus diarrhoea was 11.0 +/- 3.6 compared to 4.5 +/- 1.9 for the 112 episodes of non-rotavirus diarrhea in the same population. Our study indicates that ELISA, which is easier to perform, faster and cheaper than cell culture methods may be suitable for routine diagnosis of rotavirus infections. The severity of rotavirus positive gastroenteritis was significantly higher than that of rotavirus negative patients.

Etiology, Seasonality, and Clinical Features of Viral Respiratory Tract Infections in Children Hospitalized With Acute Bronchiolitis: A Single-Center Study.

The purpose of this study was to evaluate the viral frequency, seasonality, and clinical and demographic features of patients hospitalized with acute bronchiolitis. A cross-sectional, descriptive study was performed in 316 infants younger than 2 years of age who were hospitalized for acute viral bronchiolitis. Respiratory tract infection agents were investigated with polymerase chain reaction (PCR). A total of 316 infants were included in this study. Of the 316 infants, at least one respiratory tract pathogen was detected in 75% (237/316). Respiratory syncytial virus (RSV) was the most common virus identified in 127 infants (40.1%) followed by rhinovirus (n = 78, 24.6%). In this study, where viral agents were determined via PCR in patients who were followed-up due to the diagnosis of acute bronchiolitis, RSV was detected as the most common agent, as in other studies. In almost half of the RSV-positive patients, RSV was accompanied by a second or third agent.

Pyoderma gangrenosum in a six-month-old boy.

Pyoderma gangrenosum (PG) is an uncommon, chronic ulcerative condition of the skin that was first described in 1930. It can occur in any age group, but only 4% of the patients are infants or children. An underlying systemic disease is present in approximately 50% of the patients with PG. The most common associations include inflammatory bowel disease, arthritis, lymphoproliferative disorders and chronic recurrent multifocal osteomyelitis (CRMO). PG has been reported in association with CRMO in only a few children whose ages were between 18 months and 12 years. We report a six-month-old boy who was diagnosed as CRMO based on his clinical examination and histological findings. This is the youngest case reported in the literature (under 12 months of age) with PG associated with CRMO.

Serum immunoglobulin (IgG, IgM, IgA) and IgG subclass concentrations in healthy children: a study using nephelometric technique.

Immunoglobulin (Ig) G, IgM, IgA and IgG subclass (IgG1, IgG2, IgG3, IgG4) concentrations were determined in more than 500 healthy Turkish children using nephelometric technique. These parameters were thought to be highly varied for different ethnic groups because of environmental and genetic factors. Methodology used in previous studies has been reported to affect age-related normal values. Serum IgG, IgM, IgA and IgG1, IgG2, IgG3, IgG4 levels were measured in 510, 491, 486, 542, 511, 515, and 545 healthy children, respectively. According to their age, the patients were divided into 14 groups. In contrast to most of the previous studies, age-related normal values for IgG4 levels were also obtained. In conclusion, it has been suggested that our study as an example for Caucasians using nephelometric technique will supply useful information about age-related normal serum immunoglobulin and IgG subclass concentrations.

Might there be a link between mannose-binding lectin polymorphism and dental caries?

The aim of this study is to analyze two polymorphisms in exon 1 of Mannose-binding lectin (MBL) gene in children with carious teeth and children caries-free in order to determine the frequencies of these polymorphisms and to investigate possible association between MBL polymorphisms and dental caries. Fourty-two children with carious teeth and 40 children caries-free participated in the study. Two-hundred microliters of peripheral blood samples were taken in EDTA tubes and genomic DNA was isolated. PCR-RFLP method was used with BanI and MboII digestion enzymes. The overall distribution of genotypes did not significantly differ between two groups and there was also no significant difference in the allele frequency of codon 54 wild type (allele A) (p=0.884, p=0.585). It has been concluded that further investigations may be required to show possible association between MBL and dental caries in which high number healthy children are participated.

High frequency of pertussis in older children and adolescents with prolonged cough in Turkey.

This study aimed to determine the frequency of B. pertussis infection among Turkish children with prolonged cough. Nasopharyngeal specimens were collected from 7-18 year old children, presenting with prolonged cough of two to four weeks' duration. Specimens were examined for B. pertussis by PCR. Of 101 children with prolonged cough, 20 (19.8%) had a positive PCR testing for B. pertussis. Children who were vaccinated ≥5 years previously had a 6.13-fold higher risk of PCR-confirmed pertussis than those who were vaccinated < 5 years before. The classic symptoms of pertussis (paroxysmal cough, whooping and post-tussive vomiting) were seen in 30%, 15% and 25% of the patients with positive PCR, respectively; 55% of them had only a prolonged cough without any classic symptoms. Pertussis is common among Turkish children with prolonged cough, even after implementation of a fifth dose of pertussis vaccination and despite high vaccination coverage.

Comparison of Vesikari and Clark scales regarding the definition of severe rotavirus gastroenteritis in children.

BACKGROUND: Two clinical severity scales, the Vesikari scale and the Clark scale, are commonly used to assess the efficacy of rotavirus vaccines. The results obtained using the two severity scales differ significantly and hamper comparisons. The aim of this study was to compare the Clark and Vesikari scales and to determine whether modified classifications would provide a better correlation between the two scales. METHODS: The severity of rotavirus gastroenteritis was assessed for each child using both the Vesikari and Clark scales. To make a statistical comparison between the two scales, the classifications were modified. RESULTS: In total, 200 children with rotavirus gastroenteritis were evaluated. Of these, 57% were classified as severe by the Vesikari scale, and only 1.5% by the Clark scale (p < 0.001). When the Clark three-category scale was transformed into a two-category scale by merging mild and moderate categories as non-severe, a good correlation with the Vesikari scale still could not be found. Using the median of the severity scores as the severity threshold did not provide a better correlation between the two scales. Transforming the Vesikari two-category scale into a three-category scale by further subdividing the severe category into two parts, as moderate and severe (≥ 16), provided a better correlation between the two severity scales, but still did not achieve a good level of agreement. CONCLUSIONS: The Clark and Vesikari scales differ significantly in the definition of severe gastroenteritis. Even the attempts at reclassifying the scales did not achieve a good correlation.

A Clinical and Laboratory Approach to the Evaluation of Innate Immunity in Pediatric CVID Patients.

Defective adaptive immune responses are well studied in common variable immunodeficiency (CVID) patients; however, more focus is needed on innate immune system defects to explain CVID's clinical and laboratory heterogeneity. This is the first study comparing migratory function of granulocytes, oxidative burst activity of phagocytic cells, surface integrin expressions on neutrophils and lymphocytes, natural killer (NK) cell numbers and cytotoxic activity, natural killer T cells, lymphocyte subsets such as CD8(+)CD28(+), CD4(+)CTLA-4(+) cells in CVID patients (n: 20) and healthy controls (n: 26). The relationship between laboratory findings and some clinical was also investigated. CD3(+)CD8(+) T cytotoxic cells were found to be elevated in CVID patients, but CD3(+)CD8(+)CD28(+) or CD3(+)CD8(+)CD28(-) cells did not show any significant difference. CD4(+)CTLA-4(+) cell percentages were significantly lower in CVID patients compared to healthy controls. Severe CVID patients had decreased percentages of NK cells with increased NK cell cytotoxicity suggesting possibly increased activation. Furthermore, CD3(-)CD16(+)CD56(+)CD28(+) cells of CVID patients were elevated while percentage of CD28(-) NK cells was decreased. Neutrophil migration percentages were lower but and oxidative burst activity was not affected. CD11a expressions on these cells were depressed in contrast to increased expression of CD18. Innate immunity defects may affect the extent of recurrence and severity of infections in CVID. Our observations highlight some of these associations and indicate the need for further similar studies for improving better innate system evaluation batteries for these patients. Further phenotypic correlations of these analyses will help clinicians reach a more definitive target for the molecular genetic diagnostic of pediatric CVID patients.

Severe Hemolytic Anemia Associated with Mild Pneumonia Caused by Mycoplasma pneumonia.

We report a case of M. pneumoniae infection presenting with severe hemolytic anemia in a 4-year-old girl, with a ten-day history of paleness, weakness, and nonproductive cough. She was very pale and tachycardic. However, she was not tachypneic. Chest examination showed normal breath sounds. No rhoncus or whistling was heard. As the erythrocyte sedimentation rate was excessively elevated, the differential diagnosis primarily comprised hematological malignancies. Direct Coombs' test was positive. Diagnosis of M. pneumoniae infection was confirmed by elevated levels of M. pneumoniae IgG and IgM antibodies and a chest X-ray suggestive of atypical pneumonia. The patient was treated with clarithromycin and packed red cell transfusion and showed a favorable recovery within ten days after admission. In conclusion, this case demonstrates that severe hemolytic anemia caused by M. pneumoniae is not always associated with severe pulmonary involvement, even when the respiratory infection is very mild, M. pneumoniae may be the cause of severe anemia.